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As Filed With The Securities And Exchange Commission On November 10, 1999

SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

AMENDMENT No. 2

TO
SCHEDULE 13E-3

RULE 13E-3 TRANSACTION STATEMENT
(PURSUANT TO SECTION 13(E) OF THE SECURITIES EXCHANGE
ACT OF 1934 AND RULE 13E-3 ((S) 240.13E-3) THEREUNDER)

COGENERATION CORPORATION OF AMERICA
--------------------------------------------------------------------------------
(Name of the Issuer)

NRG ENERGY, INC.
COGENERATION CORPORATION OF AMERICA
--------------------------------------------------------------------------------
(Name of Person(s) Filing Statement)

COMMON STOCK, PAR VALUE $0.01 PER SHARE
--------------------------------------------------------------------------------
(Title of Class of Securities)

628950-10-7
--------------------------------------------------------------------------------
(CUSIP Number of Class of Securities)

James J. Bender                             Julie A. Jorgensen
Vice President and General Counsel         President and Chief Executive Officer
NRG Energy, Inc.                    Cogeneration Corporation of America
1221 Nicollet Mall, Suite 700                 One Carlson Parkway, Suite 240
Minneapolis, MN 55403-2445                     Minneapolis, MN 55447-4454
(612) 373-5300                                (612) 745-7900

(Name, Address and Telephone Number of Person Authorized to Receive Notices
and Communications on Behalf of Person(s) Filing Statement)

Copies to:

Jeanine L. Matte, Esq.                     Bruce J. Parker, Esq.
Pankaj K. Sinha, Esq.                 Kaplan, Strangis and Kaplan, P.A.
Skadden, Arps, Slate, Meagher & Flom LLP           5500 Norwest Center
1440 New York Avenue, N.W.                 90 South Seventh Street
Washington, D.C. 20005-2111                  Minneapolis, MN 55402
(202) 371-7000                             (612) 904-5600

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This statement is filed in connection with (check the appropriate box):

a. [x] The filing of solicitation materials or an information statement subject 
to Regulation 14A, Regulation 14C or Rules 13e-3(c) under the Securities
Exchange Act of 1934.

b. [ ] The filing of a registration statement under the Securities Act of 1933.

c. [ ] A tender offer.

d. [ ] None of the above.

Check the following box if the soliciting materials or information statement
referred to in checking box (a) are preliminary copies:  [x]

CALCULATION OF FILING FEE

Transaction Valuation       Amount of Filing Fee

$183,463,413.00               $36,692.69

[x] Check box if any part of the fee is offset as provided by Rule 0-11(a)(2)
and identify the filing with which the offsetting fee was previously paid.
Identify the previous filing by registration statement number, or the form or
schedule and the date of its filing.

Amount Previously Paid: $36,692.69

Form or Registration Number: Schedule 14A

Filing Party: Cogeneration Corporation of America

Date Filed: November 10, 1999  

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INTRODUCTION

This Rule 13e-3 Transaction Statement on Schedule 13E-3 (the "Schedule 13E-3")
is being filed by NRG Energy, Inc., a corporation organized under the laws of
Delaware ("NRG"), and Cogeneration Corporation of America, a corporation
organized under the laws of Delaware ("CogenAmerica"), pursuant to Section 13(e)
of the Securities Exchange Act of 1934, as amended, and Rule 13(e) 3 thereunder,
in connection with the Agreement and Plan of Merger, dated as of August 26, 1999
(the "Merger Agreement"), by and among Calpine Corporation ("Calpine"), Calpine
East Acquisition Corp. ("Acquisition Sub") and CogenAmerica, pursuant to which
Acquisition Sub will merge with and into CogenAmerica, with CogenAmerica
continuing as the surviving corporation.

The following Cross Reference Sheet, prepared pursuant to General Instruction F
to Schedule 13E-3, shows the location in the Proxy Statement of CogenAmerica
filed with the Securities and Exchange Commission on the date hereof of the
information required to be included in this Schedule 13E-3. The information set
forth in the Proxy Statement, including all exhibits thereto, is hereby
expressly incorporated herein by reference as set forth in the Cross Reference
Sheet and the responses in this Schedule 13E-3, and such responses are qualified
in their entirety by reference to the information contained in the Proxy
Statement.

The information contained in this Schedule 13E-3 concerning CogenAmerica,
including, without limitation, information concerning the background of the
transaction, the deliberations of CogenAmerica's Board of Directors in
connection with the transaction, the opinion of CogenAmerica's financial
advisor, and CogenAmerica's capital structure and historical financial
statements, was supplied by CogenAmerica. NRG, Calpine and Acquisition Sub take
no responsibility for the accuracy of such information. The information
contained in this Schedule 13E-3 concerning Calpine and Acquisition Sub was
supplied by Calpine. CogenAmerica and NRG take no responsibility for the
accuracy of such information. The information contained in this Schedule 13E-3
concerning NRG was supplied by NRG. CogenAmerica, Calpine and Acquisition Sub
take no responsibility for the accuracy of such information.

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CROSS-REFERENCE SHEET

SCHEDULE 13E-3                         LOCATION IN PROXY STATEMENT
ITEM NUMBER AND CAPTION                    ---------------------------
-----------------------

Item 1(a)...................................    Outside Front Cover Page;
QUESTIONS AND ANSWERS
ABOUT THE MERGER; SUMMARY -
The Companies

Item 1(b)...................................    SUMMARY - The Special Meeting;
THE SPECIAL MEETING - Record 
Date; Voting Power; Votes
Required

Item 1(c)...................................    HISTORICAL MARKET INFORMATION

Item 1(d)...................................    HISTORICAL MARKET INFORMATION

Item 1(e)...................................    Not applicable.

Item 1(f)...................................    Not applicable.

Item 2(a)-(d),(g)...........................    Not applicable.

Item 2(e)-(f)...............................    Not applicable.

Item 3(a)(1)................................    Outside Front Cover Page; 
SPECIAL FACTORS -
Background of the Merger; -
Reasons for the Merger; -
Conflicts of Interest -
Arrangements with NRG

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Item 3(a)(2)and(b)..........................    Outside Front Cover Page;
SUMMARY - Recommendations of the
Independent Directors
Committee and the Board of
Directors; SPECIAL FACTORS -
Background of the Merger; -
Reasons for the Merger;
-Conflicts of Interest -
Arrangements with NRG

Item 4(a)...................................    QUESTIONS AND ANSWERS
ABOUT THE MERGER; SUMMARY -
Terms of the Merger
Agreement; SPECIAL FACTORS -
Purpose, Timing and
Structure of the Merger;
SUMMARY OF MATERIAL FEATURES
OF THE MERGER

Item 4(b)...................................    QUESTIONS AND ANSWERS ABOUT THE
MERGER; SUMMARY - Terms of the
Merger Agreement; SPECIAL
FACTORS - Purpose, Timing and 
Structure of the Merger; SUMMARY
OF MATERIAL FEATURES OF THE
MERGER; SUMMARY OF MATERIAL
FEATURES OF THE CALPINE/NRG
AGREEMENT

Item 5(a)-(b)...............................    SUMMARY - Terms of the Merger
Agreement; SPECIAL FACTORS - 
Background of the Merger; - 
Plans for CogenAmerica After 
the Merger; - Conflicts of 
Interest - Arrangements with 
NRG; SUMMARY OF MATERIAL 
FEATURES OF THE MERGER; 
SUMMARY OF MATERIAL FEATURES OF
THE CALPINE/NRG AGREEMENT

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Item 5(c)-(d)...............................    SUMMARY - Terms of the Merger
Agreement; SPECIAL FACTORS -
Purpose, Timing and Structure of
the Merger; - Plans for
CogenAmerica After the Merger;
SUMMARY OF MATERIAL FEATURES OF
THE MERGER; SUMMARY OF MATERIAL
FEATURES OF THE CALPINE/NRG
AGREEMENT

Item 5(e)...................................    QUESTIONS AND ANSWERS ABOUT THE
MERGER; SUMMARY - Terms of the
Merger Agreement; SPECIAL
FACTORS - Purpose, Timing and
Structure of the Merger; -
Plans for CogenAmerica After the
Merger; SUMMARY OF MATERIAL
FEATURES OF THE MERGER; SUMMARY
OF MATERIAL FEATURES OF THE
CALPINE/NRG AGREEMENT 

Item 5(f)-(g)...............................    QUESTIONS AND ANSWERS ABOUT THE
MERGER; SUMMARY - Terms of the
Merger Agreement; SPECIAL
FACTORS - Purpose, Timing and
Structure of the Merger; SUMMARY
OF MATERIAL FEATURES OF THE
MERGER; SPECIAL FACTORS -
Certain Effects of the Merger

Item 6(a) and (d)...........................    SUMMARY OF MATERIAL FEATURES OF
THE MERGER - Financing of the
Merger; Source of Funds

Item 6(b)...................................    EXPENSES OF THE TRANSACTION

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Item 7(a)-(c)..............................     SUMMARY - Potential Benefits and
Detriments of the Merger to
Unaffiliated Stockholders;
Benefits to Insiders; SPECIAL
FACTORS -  Background of the
Merger; - Purpose, Timing and
Structure of the Merger; 
- Reasons for the Merger;
- Perspective of NRG on the 
Fairness of the Merger 

Item 7(d)..................................     SUMMARY - Potential Benefits and
Detriments of the Merger to
Unaffiliated Stockholders;
Benefits to Insiders; SPECIAL
FACTORS - Background of the
Merger; - Purpose, Timing and
Structure of the Merger; 
- Reasons for the Merger; -
Perspective of NRG on the
Fairness of the Merger; SUMMARY
OF MATERIAL FEATURES OF THE
MERGER - Federal Income Tax
Consequences of the Transaction

Item 8(a) .................................     QUESTIONS AND ANSWERS ABOUT THE
MERGER; SUMMARY - 
Recommendations of the
Independent Directors Committee
and the Board of Directors; -
Opinion of CogenAmerica's
Financial Advisor; SPECIAL
FACTORS - Background of the
Merger; - Purpose, Timing and
Structure of the Merger; -
Reasons for the Merger; -
Opinion of Financial Advisor; -
Perspective of NRG on the
Fairness of the Merger 

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Item 8(b)...............................        SUMMARY - Recommendations of the
Independent Directors Committee
and the Board of Directors; -
Opinion of CogenAmerica's
Financial Advisor; SPECIAL
FACTORS - Background of the
Merger; - Purpose, Timing and
Structure of the Merger; -
Reasons for the Merger; -
Opinion of Financial Advisor; -
Perspective of NRG on the
Fairness of the Merger

Item 8(c)...............................        SUMMARY - Record Date;
Voting Power; Votes Required;
THE SPECIAL MEETING - Record
Date; Voting Power; Votes 
Required; SUMMARY OF MATERIAL
FEATURES OF THE MERGER - The
Merger - Conditions to the
Merger

Item 8(d)...............................        SPECIAL FACTORS - Background of 
the Merger; - Recommendations of
the Independent Directors 
Committee and the Board of 
Directors

Item 8(e)...............................        SUMMARY - Record Date;
Voting Power; Votes Required; 
SPECIAL FACTORS - Background of
the Merger; - Recommendations of
the Independent Directors 
Committee and the Board of 
Directors; THE SPECIAL MEETING -
Record Date; Voting Power;
Votes Required; SUMMARY OF
MATERIAL FEATURES OF THE MERGER
- The Merger - Conditions to the
Merger

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Item 8(f)...............................        SPECIAL FACTORS - Background of
the Merger; - Reasons for the
Merger; - Recommendations of the
Independent Directors Committee
and the Board of Directors

Item 9(a)-(c)............................       SUMMARY - Opinion of
CogenAmerica's Financial
Advisor; - Recommendations of
the Independent Directors
Committee and the Board of
Directors; SPECIAL FACTORS -
Opinion of Financial Advisor

Item 10(a)...............................       SUMMARY - Record Date; Voting 
Power; Votes Required; THE
SPECIAL MEETING - Record Date;
Voting Power; Votes Required;
INTEREST IN SECURITIES OF 
COGENAMERICA

Item 10(b)...............................       CERTAIN TRANSACTIONS IN COMMON
STOCK AND STOCK OPTIONS 

Item 11..................................       SUMMARY OF MATERIAL FEATURES OF
THE MERGER; SUMMARY OF MATERIAL
FEATURES OF THE CALPINE/NRG
AGREEMENT

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Item 12(a)-(b).........................         SUMMARY - Recommendations of the
Independent Directors Committee
and the Board of Directors; THE
SPECIAL MEETING - Record Date;
Voting Power; Votes Required;
SPECIAL FACTORS - Reasons for
the Merger; - Recommendations of
the Independent Directors
Committee and the Board of
Directors; - Perspective of NRG
on the Fairness of the Merger; -
Conflicts of Interest; SUMMARY
OF MATERIAL FEATURES OF THE
CALPINE/NRG AGREEMENT

Item 13(a).............................         SUMMARY - Appraisal Rights; 
SUMMARY OF MATERIAL FEATURES OF
THE MERGER - Appraisal Rights

Item 13(b)-(c).........................         Not applicable. 

Item 14(a).............................         SELECTED CONSOLIDATED FINANCIAL
DATA OF COGENAMERICA;
INCORPORATION OF CERTAIN
DOCUMENTS BY REFERENCE 

Item 14(b).............................         Not applicable. 

Item 15(a)-(b).........................         THE SPECIAL MEETING - General;
EXPENSES OF THE TRANSACTION

Item 16................................         Not applicable.

Item 17(a).............................         Not applicable.  

Item 17(b).............................         Fairness Opinion, dated as of
August 26, 1999, delivered by
Donaldson, Lufkin & Jenrette
Securities Corporation (set
forth as Appendix C to the Proxy
Statement which is filed as
Exhibit (d) hereto)*

Item 17(c)(1)..........................         Agreement and Plan of Merger
among Cogeneration Corporation
of America, Calpine Corporation
and Calpine East Acquisition
Corp., dated as of August 26,
1999 (set forth as Appendix A to
the Proxy Statement which is
filed as Exhibit (d) hereto)*

Item 17(c)(2)..........................         Contribution and Stockholders
Agreement, dated as of August
26, 1999, among Calpine
Corporation, Calpine East
Acquisition Corp. and NRG
Energy, Inc.

Item 17(d).............................         Copies of each of the
Preliminary Proxy Statement of
Cogeneration Corporation of
America, Letter to Stockholders
and Notice of Special Meeting of
Stockholders

Item 17(e).............................         Section 262 of the Delaware
General Corporation Law (set
forth as Appendix D to the Proxy
Statement which is filed as
Exhibit (d) hereto)*

Item 17(f).............................         Not applicable.

* Incorporated by reference to the Proxy Statement

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ITEM 1.        ISSUER AND CLASS OF SECURITY SUBJECT TO THE TRANSACTION.

(a)     The information set forth on the Outside Front Cover Page and in
"QUESTIONS AND ANSWERS ABOUT THE MERGER" and "SUMMARY - The Companies" of the
Proxy Statement is incorporated herein by reference.

(b)     The information set forth in "SUMMARY - The Special Meeting" and
"THE SPECIAL MEETING - Record Date; Voting Power; Votes Required" of the Proxy
Statement is incorporated herein by reference.

(c)     The information set forth in "HISTORICAL MARKET INFORMATION" of
the Proxy Statement is incorporated herein by reference.

(d)     The information set forth in "HISTORICAL MARKET INFORMATION" of
the Proxy Statement is incorporated herein by reference.

(e)     Not applicable.

(f)     On April 30, 1996, NRG received an option to convert $3,000,000 
of the outstanding principal amount of the loan then existing between NRG and
O'Brien (Schuylkill) Cogeneration, Inc. ("Schuylkill") into 396,255 shares of
common stock of CogenAmerica. Such option vested on August 22, 1997 when NRG
loaned additional funds to Schuylkill. On Novermber 25, 1997, NRG converted
$3,000,000 of the loan balance into 396,255 shares at a per share price of
approximately $7.57. The average price of CogenAmerica's common stock was $16.40
and $19.48, respectively, for the third and fourth quarters of 1997.

ITEM 2.        IDENTITY AND BACKGROUND.

This Statement is being filed jointly by NRG and CogenAmerica
(the "Filing Persons"). The information set forth on the Outside Front Cover
Page and in "SUMMARY - The Companies" of the Proxy Statement is incorporated
herein by reference.

(a)-(d) Not applicable.

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(e)     During the last five years, none of the Filing Persons nor, to 
the best of their respective knowledge, any of their directors, executive 
officers or controlling persons have been convicted in a criminal proceeding 
(excluding traffic violations or similar misdemeanors).

(f)     During the last five years, none of the Filing Persons nor, to 
the best of their respective knowledge, any of their directors, executive 
officers or controlling persons was a party to a civil proceeding of a judicial 
or administrative body of competent jurisdiction and as a result of such
proceeding was or is subject to a judgment, decree or final order enjoining
further violations of, or prohibiting activities, subject to, federal or state
securities laws or finding any violation of such laws.

(g)     Not applicable.

ITEM 3.        PAST CONTACTS, TRANSACTIONS OR NEGOTIATIONS.

(a)(1)  The information set forth on the Outside Front Cover Page and in
"SPECIAL FACTORS - Background of the Merger"; "- Reasons for the Merger"; 
"- Conflicts of Interest - Arrangements with NRG" of the Proxy Statement is
incorporated herein by reference.

(a)(2) and (b)   The information set forth on the Outside Front Cover
Page and in "SUMMARY - Recommendations of the Independent Directors Committee
and the Board of Directors"; and "SPECIAL FACTORS - Background of the Merger";
"- Reasons for the Merger"; "- Conflicts of Interest - Arrangements with NRG" of
the Proxy Statement is incorporated herein by reference.

In addition, on September 14, 1998, NRG sent a letter to
CogenAmerica's Chairman requesting that he call a special meeting of
CogenAmerica's stockholders to consider removal of Robert Sherman from
CogenAmerica's Board of Directors. NRG also filed definitive solicitation
materials with the Securities and Exchange Commission pursuant to Section 14(a)
of the Securities and Exchange Act of 1934, as amended, relating to a proposed
solicitation of proxies and consents from CogenAmerica's stockholders to remove
Mr. Sherman from CogenAmerica's Board of Directors. On October 26, 1998,
consents of over

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50% of CogenAmerica's stockholders in favor of Mr. Sherman's removal from 
CogenAmerica's Board of Directors were filed with CogenAmerica and Mr. Sherman
was removed from CogenAmerica's Board of Directors.

ITEM 4.        TERMS OF THE TRANSACTION.

(a)     The information set forth in "QUESTIONS AND ANSWERS ABOUT THE
MERGER"; "SUMMARY - Terms of the Merger Agreement"; "SPECIAL FACTORS - Purpose,
Timing and Structure of the Merger"; and "SUMMARY OF MATERIAL FEATURES OF THE
MERGER" of the Proxy Statement is incorporated herein by reference.

(b)     The information set forth in "QUESTIONS AND ANSWERS ABOUT THE
MERGER"; "SUMMARY - Terms of the Merger Agreement"; "SPECIAL FACTORS - Purpose,
Timing and Structure of the Merger"; "SUMMARY OF MATERIAL FEATURES OF THE
MERGER"; and "SUMMARY OF MATERIAL FEATURES OF THE CALPINE/NRG AGREEMENT" of the
Proxy Statement is incorporated herein by reference.

ITEM 5.        PLANS OR PROPOSALS OF THE ISSUER OR AFFILIATE.

(a) - (b)   The information set forth in "SUMMARY - Terms of the Merger
Agreement"; "SPECIAL FACTORS - Background of the Merger"; " - Plans for
CogenAmerica After the Merger"; "- Conflicts of Interest - Arrangements with
NRG"; "SUMMARY OF MATERIAL FEATURES OF THE MERGER"; and "SUMMARY OF MATERIAL
FEATURES OF THE CALPINE/NRG AGREEMENT" of the Proxy Statement is incorporated
herein by reference.

(c) - (d)   The information set forth in "SUMMARY - Terms of the Merger
Agreement"; "SPECIAL FACTORS - Purpose, Timing and Structure of the Merger"; " -
Plans for CogenAmerica After the Merger"; and "SUMMARY OF MATERIAL FEATURES OF
THE MERGER"; "SUMMARY OF MATERIAL FEATURES OF THE CALPINE/NRG AGREEMENT" of the
Proxy Statement is incorporated herein by reference.

(e)     The information set forth in "QUESTIONS AND ANSWERS ABOUT THE
MERGER"; "SUMMARY - Terms of the Merger Agreement"; "SPECIAL FACTORS - Purpose,
Timing and Structure of the Merger"; " - Plans for CogenAmerica After the
Merger"; "SUMMARY OF MATERIAL FEATURES OF THE MERGER"; and "SUMMARY OF

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MATERIAL FEATURES OF THE CALPINE/NRG AGREEMENT"; of the Proxy Statement is
incorporated herein by reference.

(f) - (g)   The information set forth in "QUESTIONS AND ANSWERS ABOUT THE
MERGER"; "SUMMARY - Terms of the Merger Agreement"; "SPECIAL FACTORS - Purpose,
Timing and Structure of the Merger"; "SUMMARY OF MATERIAL FEATURES OF THE
MERGER"; and "SPECIAL FACTORS - Certain Effects of the Merger" of the Proxy
Statement is incorporated herein by reference.

ITEM 6.        SOURCE AND AMOUNTS OF FUNDS OR OTHER CONSIDERATION.

(a) and (d) The information set forth in "SUMMARY OF MATERIAL FEATURES
OF THE MERGER - Financing of the Merger; Source of Funds" of the Proxy Statement
is incorporated herein by reference.

(b)     The information set forth in "EXPENSES OF THE TRANSACTION" of the
Proxy Statement is incorporated herein by reference.

(c )    Not applicable.

ITEM 7.        PURPOSE(S), ALTERNATIVES, REASONS AND EFFECTS.

(a) - (c)   The information set forth in "SUMMARY - Potential Benefits
and Detriments of the Merger to Unaffiliated Stockholders; Benefits to
Insiders"; and "SPECIAL FACTORS - Background of the Merger"; "- Purpose, Timing
and Structure of the Merger"; "- Reasons for the Merger"; "- Perspective of NRG
on the Fairness of the Merger" of the Proxy Statement is incorporated herein by
reference.

(d)     The information set forth in "SUMMARY - Potential Benefits and
Detriments of the Merger to Unaffiliated Stockholders; Benefits to Insiders";
"SPECIAL FACTORS - Background of the Merger"; "- Purpose, Timing and Structure
of the Merger"; "- Reasons for the Merger"; "- Perspective of NRG on the
Fairness of the Merger"; and "SUMMARY OF MATERIAL FEATURES OF THE MERGER -
Federal 

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Income Tax Consequences of the Transaction" of the Proxy Statement is 
incorporated herein by reference.

ITEM 8.        FAIRNESS OF THE TRANSACTION.

(a)     The information set forth in "QUESTIONS AND ANSWERS ABOUT THE
MERGER"; "SUMMARY - Recommendations of the Independent Directors Committee and
the Board of Directors"; "- Opinion of CogenAmerica's Financial Advisor"; and
"SPECIAL FACTORS - Background of the Merger"; "- Purpose, Timing and Structure
of the Merger"; "- Reasons for the Merger"; "- Opinion of Financial Advisor";
"- Perspective of NRG on the Fairness of the Merger" of the Proxy Statement is
incorporated herein by reference.

(b)     The information set forth in "SUMMARY - Recommendations of the
Independent Directors Committee and the Board of Directors"; "- Opinion of
CogenAmerica's Financial Advisor"; and "SPECIAL FACTORS - Background of the
Merger"; "- Purpose, Timing and Structure of the Merger"; "- Reasons for the
Merger"; "- Opinion of Financial Advisor"; "- Perspective of NRG on the Fairness
of the Merger" of the Proxy Statement is incorporated herein by reference.

(c)     The information set forth in "SUMMARY - Record Date; Voting
Power; Votes Required"; "THE SPECIAL MEETING - Record Date; Voting Power;
Votes Required" and "SUMMARY OF MATERIAL FEATURES OF THE MERGER - The Merger -
Conditions to the Merger" of the Proxy Statement is incorporated herein by 
reference.

(d)     The information set forth in "SPECIAL FACTORS - Background of the
Merger"; "- Recommendations of the Independent Directors Committee and the
Board of Directors" of the Proxy Statement is incorporated herein by reference.

(e)     The information set forth in "SUMMARY - Record Date; Voting 
Power; Votes Required"; "SPECIAL FACTORS - Background of the Merger"; "- 
Recommendations of the Independent Directors Committee and the Board of 
Directors"; "THE SPECIAL MEETING - Record Date; Voting Power;
Votes Required" and "SUMMARY OF MATERIAL FEATURES OF THE MERGER - The Merger - 
Conditions to the Merger" of the Proxy Statement is incorporated herein by
reference.

(f)     The information set forth in "SPECIAL FACTORS - Background of the
Merger"; "- Reasons for the Merger"; "- Recommendations of the Independent

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Directors Committee and the Board of Directors" of the Proxy Statement is
incorporated herein by reference.

ITEM 9.        REPORTS, OPINIONS, APPRAISALS AND CERTAIN NEGOTIATIONS.

(a) - (c)   The information set forth in "SUMMARY - Opinion of 
CogenAmerica's Financial Advisor"; "- Recommendations of the Independent 
Directors Committee and the Board of Directors"; and "SPECIAL FACTORS - Opinion
of Financial Advisor" of the Proxy Statement is incorporated herein by 
reference.

ITEM 10.       INTEREST IN SECURITIES OF THE ISSUER.

(a)     The information set forth in "SUMMARY - Record Date; Voting 
Power; Votes Required"; "THE SPECIAL MEETING - Record Date; Voting Power; Votes
Required" and "INTEREST IN SECURITIES OF COGENAMERICA" of the Proxy Statement is
incorporated herein by reference.

(b)     The information set forth in "CERTAIN TRANSACTIONS IN COMMON 
STOCK AND STOCK OPTIONS" of the Proxy Statement is incorporated herein by 
reference.

ITEM 11.       CONTRACTS, ARRANGEMENTS OR UNDERSTANDINGS WITH RESPECT TO THE 
ISSUER'S SECURITIES.

The information set forth in "SUMMARY OF MATERIAL FEATURES OF THE 
MERGER"; and "SUMMARY OF MATERIAL FEATURES OF THE CALPINE/NRG AGREEMENT" of the
Proxy Statement is incorporated herein by reference.

ITEM 12.       PRESENT INTENTION AND RECOMMENDATION OF CERTAIN PERSONS WITH 
REGARDS TO THE TRANSACTION.

(a)-(b)     The information set forth in "SUMMARY - Recommendations of
the Independent Directors Committee and the Board of Directors"; "THE SPECIAL
MEETING - Record Date; Voting Power; Votes Required"; "SPECIAL FACTORS - Reasons
for the Merger"; "- Recommendations of the Independent Directors Committee and
the Board of Directors"; "- Perspective of NRG on the Fairness of the 

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Merger"; "- Conflicts of Interest"; and "SUMMARY OF MATERIAL FEATURES OF THE
CALPINE/NRG AGREEMENT" of the Proxy Statement is incorporated herein by 
reference.

ITEM 13.       OTHER PROVISIONS OF THE TRANSACTION.

(a)     The information set forth in "SUMMARY - Appraisal Rights"; and
"SUMMARY OF MATERIAL FEATURES OF THE MERGER - Appraisal Rights" of the Proxy
Statement is incorporated herein by reference.

(b)-(c) Not Applicable.

ITEM 14.       FINANCIAL INFORMATION.

(a)     The information set forth in "SELECTED CONSOLIDATED FINANCIAL 
DATA OF COGENAMERICA"; and "INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE" of
the Proxy Statement is incorporated herein by reference.

(b)     Not Applicable.

ITEM 15.       PERSONS AND ASSETS EMPLOYED, RETAINED OR UTILIZED.

(a)-(b) The information set forth in "THE SPECIAL MEETING - General";
and "EXPENSES OF THE TRANSACTION" of the Proxy Statement is incorporated herein
by reference.

ITEM 16.       ADDITIONAL INFORMATION.

Not Applicable.

ITEM 17.       MATERIAL TO BE FILED AS EXHIBITS.

(a)     Not Applicable.

(b)     Fairness Opinion, dated as of August 26, 1999, delivered by
Donaldson, Lufkin & Jenrette Securities Corporation (set forth as Appendix C to
the Proxy Statement which is filed as Exhibit (d) hereto)*

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(c)(1)  Agreement and Plan of Merger among Cogeneration Corporation of
America, Calpine Corporation and Calpine East Acquisition Corp., dated August
26, 1999 (set forth as Appendix A to the Proxy Statement which is filed as
Exhibit (d) hereto)*

(c)(2)  Contribution and Stockholders Agreement, dated as of August 26, 
1999, among Calpine Corporation, Calpine East Acquisition Corp. and NRG Energy,
Inc.

(d)     Copies of each of the Preliminary Proxy Statement of Cogeneration
Corporation of America, Letter to Stockholders and Notice of Special Meeting of
Stockholders, filed with the SEC on November 10, 1999

(e)     Section 262 of the Delaware General Corporation Law (set forth
as Appendix D to the Proxy Statement which is filed as Exhibit (d) hereto)*

(f)     As of the date of this Statement, no written instruction, form or
other material has been furnished to any person making the actual oral
solicitation or other recommendation (including the proxy solicitor referred to
in "THE SPECIAL MEETING - Voting Procedures; Proxies" of the Proxy Statement) 
for such person's use, directly or indirectly in connection with the Rule 13e-3
transaction.

*Incorporated by reference to the Proxy Statement

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SIGNATURES

After due inquiry and to the best of our knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Dated:  November 10, 1999

NRG ENERGY, INC.

By: /s/ James J. Bender
-------------------------------------
Name: James J. Bender
Title: Vice President and General Counsel

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SIGNATURES

After due inquiry and to the best of our knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Dated:  November 10, 1999

COGENERATION CORPORATION OF
AMERICA

By: /s/ Julie A. Jorgensen
------------------------------------
Name: Julie A. Jorgensen
Title: President and Chief 
Executive Officer

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EXHIBIT INDEX

EXHIBIT                                          DESCRIPTION

99(c)(2)*                               Contribution and Stockholders Agreement,
dated as of August 26, 1999, among 
Calpine Corporation, Calpine East 
Acquisition Corp. and NRG Energy, Inc.
99(d)                                   Copies of each of the Definitive Proxy
America, Letter to Stockholders and 
Notice of Special Meeting of 
Stockholders

* Previously filed as Exhibit 99(c)(2) to Schedule 13E-3 filed with the 
Securities and Exchange Commission on September 24, 1999.

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[COGENERATION CORPORATION OF AMERICA LOGO]

COGENERATION CORPORATION OF AMERICA

One Carlson Parkway, Suite 240
Minneapolis, Minnesota 55447-4454

November 12, 1999

Dear Stockholder:

You are cordially invited to attend a special meeting of stockholders of
Cogeneration Corporation of America ("CogenAmerica") to be held on December 16,
1999 at 9:00 a.m., local time, at The Marquette Hotel, Universe Room, 50th
Floor, 710 Marquette Avenue, Minneapolis, Minnesota. Stockholders of record as
of November 12, 1999 are entitled to vote at the special meeting.

At the special meeting, you will be asked to approve (1) the merger of a
subsidiary of Calpine Corporation with and into CogenAmerica and (2) an
amendment to CogenAmerica's certificate of incorporation to facilitate the
merger. As a result of the merger, you will receive $25.00 in cash for each
share of CogenAmerica common stock which you own and CogenAmerica will be owned
80% by Calpine and 20% by NRG Energy, Inc., an existing stockholder.

THE COGENAMERICA BOARD OF DIRECTORS, BASED UPON THE UNANIMOUS
RECOMMENDATION OF THE INDEPENDENT DIRECTORS COMMITTEE, COMPRISED OF THREE
DISINTERESTED DIRECTORS, HAS DETERMINED THAT THE MERGER AGREEMENT IS ADVISABLE
AND IS FAIR TO, AND IN THE BEST INTERESTS OF, THE STOCKHOLDERS OF COGENAMERICA
(OTHER THAN NRG ENERGY, INC.), AND HAS UNANIMOUSLY APPROVED THE MERGER AGREEMENT
AND THE AMENDMENT AND HAS UNANIMOUSLY RECOMMENDED THAT THE COGENAMERICA
STOCKHOLDERS APPROVE AND ADOPT THE MERGER AGREEMENT AND THE AMENDMENT.

Approval and adoption of the merger agreement at the special meeting
requires the affirmative vote of the holders of more than 66 2/3% of the
outstanding shares of CogenAmerica common stock entitled to vote at the special
meeting. Approval of the charter amendment at the special meeting requires the
affirmative vote of the holders of more than 50% of the outstanding shares of
CogenAmerica common stock entitled to vote at the special meeting.

EVEN IF YOU PLAN TO ATTEND THE MEETING, WE URGE YOU TO MARK, SIGN AND DATE
THE ENCLOSED PROXY AND RETURN IT PROMPTLY. You have the option to revoke it at
any time or to vote your shares personally on request if you attend the special
meeting of stockholders. If the merger agreement and the charter amendment are
approved by the stockholders, you will receive instructions as soon as
practicable after completion of the merger on how to surrender your shares to
receive payment.
Sincerely,

DAVID H. PETERSON
David H. Peterson, Chairman

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[COGENERATION CORPORATION OF AMERICA LOGO]

COGENERATION CORPORATION OF AMERICA
One Carlson Parkway, Suite 240
Minneapolis, Minnesota 55447-4454

NOTICE OF SPECIAL MEETING OF STOCKHOLDERS
TO BE HELD ON DECEMBER 16, 1999

To the Stockholders of Cogeneration Corporation of America:

Notice is hereby given that a special meeting of stockholders of
Cogeneration Corporation of America ("CogenAmerica"), will be held on December
16, 1999 at 9:00 a.m., local time, at The Marquette Hotel, Universe Room, 50th
Floor, 710 Marquette Avenue, Minneapolis, Minnesota:

(1) To consider and vote upon a proposal to approve and adopt the
Agreement and Plan of Merger, dated as of August 26, 1999, pursuant to
which Calpine East Acquisition Corp., a Delaware corporation ("Acquisition
Sub") and a subsidiary of Calpine Corporation, a Delaware corporation, will
be merged with and into CogenAmerica, and each outstanding share of
CogenAmerica common stock, $.01 par value, other than shares owned by
CogenAmerica, Acquisition Sub and stockholders who exercise their appraisal
rights, will be converted into the right to receive $25.00 in cash. A copy
of the merger agreement is attached as Appendix A to the accompanying proxy
statement. The merger agreement is also summarized in the proxy statement.

(2) To consider and vote upon a proposal to amend CogenAmerica's
certificate of incorporation to permit NRG Energy, Inc., a Delaware
corporation ("NRG"), to transfer and contribute shares of CogenAmerica
common stock owned by NRG to Acquisition Sub immediately prior to
consummation of the merger so that, upon completion of the merger, NRG will
retain a 20% equity interest in CogenAmerica. A copy of the proposed
amendment is attached as Appendix B to the accompanying proxy statement.
The amendment is also summarized in the proxy statement.

(3) To consider and act upon such other matters as may properly come
before the special meeting or any adjournment or adjournments thereof.

A proxy card and a proxy statement containing more detailed information
with respect to the matters to be considered at the special meeting accompany
this notice.

THE INDEPENDENT DIRECTORS COMMITTEE AND THE BOARD OF DIRECTORS OF
COGENAMERICA HAVE UNANIMOUSLY APPROVED THE MERGER AGREEMENT AND THE CHARTER
AMENDMENT AND RECOMMEND THAT THE STOCKHOLDERS APPROVE AND ADOPT THE MERGER
AGREEMENT AND THE CHARTER AMENDMENT.

Only holders of CogenAmerica common stock of record at the close of
business on November 12, 1999, are entitled to notice of, and to vote at, the
special meeting. The quorum required to hold the special meeting is 60% of the
shares of CogenAmerica

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common stock entitled to vote at the meeting, present in person or by proxy. The
affirmative vote of more than 66 2/3% of the outstanding shares of CogenAmerica
common stock is required to approve the merger agreement and the affirmative
vote of more than 50% of the outstanding shares of CogenAmerica common stock is
required to approve the amendment to CogenAmerica's certificate of
incorporation. Each stockholder who signs and returns a proxy in the form
enclosed with this proxy statement may revoke the same at any time prior to its
use by giving notice of such revocation to CogenAmerica in writing or in person
at the special meeting. Unless so revoked, the shares represented by each proxy
will be voted at the special meeting and at any adjournments thereof. Presence
at the special meeting of a stockholder who has signed a proxy does not alone
revoke that proxy.

Holders of CogenAmerica common stock who do not vote their shares in favor
of the merger agreement and who strictly comply with Section 262 the Delaware
General Corporation Law (the "DGCL") have appraisal rights to make written
demand for payment of the "fair value" of their shares. For a description of the
appraisal rights of stockholders, see Section 262 of the DGCL, a copy of which
is attached as Appendix D to the accompanying proxy statement. In addition, a
description of procedures to be followed in order to exercise appraisal rights
is set forth in the accompanying proxy statement.

It is very important that your shares be represented at the special
meeting. You are urged to complete and sign the accompanying proxy card, which
is solicited by the CogenAmerica Board of Directors, and mail it promptly in the
enclosed envelope.

BY ORDER OF THE BOARD OF DIRECTORS

THOMAS L. OSTERAAS
Thomas L. Osteraas
Secretary

Minneapolis, Minnesota

November 12, 1999

PLEASE DO NOT SEND YOUR STOCK CERTIFICATES AT THIS TIME. IF THE MERGER IS
COMPLETED, YOU WILL BE SENT INSTRUCTIONS REGARDING THE SURRENDER OF YOUR STOCK
CERTIFICATES.

WHETHER OR NOT YOU ARE ABLE TO ATTEND THE MEETING, PLEASE SIGN, DATE AND
RETURN THE ACCOMPANYING PROXY CARD PROMPTLY IN THE ENCLOSED ENVELOPE WHICH
REQUIRES NO POSTAGE IF MAILED IN THE UNITED STATES.

THE TRANSACTION HAS NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION NOR HAS THE COMMISSION PASSED UPON THE FAIRNESS OR MERITS OF
THE TRANSACTION NOR UPON THE ACCURACY OR ADEQUACY OF THE INFORMATION CONTAINED
IN THIS DOCUMENT, INCLUDING THE ACCOMPANYING PROXY STATEMENT. ANY REPRESENTATION
TO THE CONTRARY IS UNLAWFUL.

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COGENERATION CORPORATION OF AMERICA
One Carlson Parkway, Suite 240
Minneapolis, Minnesota 55447-4454

PROXY STATEMENT
FOR SPECIAL MEETING OF STOCKHOLDERS
TO BE HELD ON DECEMBER 16, 1999

QUESTIONS AND ANSWERS ABOUT THE MERGER

Q: What will happen in the merger?

A: In the merger, a subsidiary of Calpine Corporation will be merged into
CogenAmerica, and CogenAmerica will be the surviving corporation. At the time of
the merger, each outstanding share of CogenAmerica common stock (other than
shares owned by CogenAmerica, by Calpine's acquisition subsidiary and by
stockholders who exercise their appraisal rights) will be converted into the
right to receive $25.00 per share in cash. After the merger, CogenAmerica will
no longer be publicly traded and will be owned 80% by Calpine and 20% by NRG
Energy, Inc., an existing stockholder of CogenAmerica. To review the structure
of the merger in greater detail, see pages 19 and 20 of this proxy statement.

Q: Why does the CogenAmerica Board of Directors recommend the merger?

A: The CogenAmerica Board of Directors believes that the sale of CogenAmerica is
in your best interests by providing you the right to receive $25.00 per share in
cash for your shares of CogenAmerica common stock. To review the background of
and reasons for the merger in greater detail, see pages 13 through 19 and 20
through 24 of this proxy statement.

Q: What will I receive in the merger?

A: You will have the right to receive $25.00 in cash, without interest, for each
share of CogenAmerica common stock that you own. For example, if you own 100
shares of CogenAmerica common stock, you will have the right to receive merger
consideration of $2,500.00 in cash upon completion of the merger.

Q: When do you expect the merger to be completed?

A: We are working to complete the merger by December 31, 1999.

Q: What are the tax consequences of the merger to me?

A: The merger will be a taxable transaction for federal income tax purposes to
CogenAmerica stockholders and option holders. To review the federal income tax
consequences to you in greater detail, see page 45 of this proxy statement. Your
tax consequences will depend on your personal situation. You should consult your
tax advisor for a full understanding of the tax consequences of the merger to
you.

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Q: What am I being asked to vote upon?

A: You are being asked to approve and adopt the merger agreement that provides
for the merger and the amendment to CogenAmerica's certificate of incorporation
that permits NRG to transfer a portion of its shares of CogenAmerica common
stock to Acquisition Sub which will allow NRG to retain a 20% interest in
CogenAmerica after the merger. The Board of Directors and the Independent
Directors Committee of CogenAmerica have unanimously approved the merger
agreement and the amendment, and recommend that the CogenAmerica stockholders
vote "FOR" the approval and adoption of the merger agreement and the amendment.

Q: What do I need to do now?

A: Simply indicate on your proxy card how you want to vote and then sign, date
and mail the proxy card in the enclosed envelope as soon as possible so that
your shares will be represented at the special meeting. In addition, you may
attend the special meeting and vote your shares in person, rather than voting by
proxy. You may withdraw your proxy up to and including the day of the special
meeting and either change your vote or attend the special meeting and vote in
person.

Q: If my shares are held in "street name" by my broker, will my broker vote my
shares for me?

A: Your broker will vote your shares only if you provide instructions on how to
vote. You should instruct your broker how to vote your shares by following the
directions your broker provides to you. If you do not provide instructions to
your broker, your shares will not be voted and they will be counted as votes
against the proposals to approve and adopt the merger agreement and the
amendment.

Q: Should I send in my stock certificates now?

A: No. After the merger is completed we will send you written instructions for
exchanging your CogenAmerica common stock certificates for the merger
consideration.

Q: Whom can I contact if I have additional questions or would like additional
copies of the proxy statement or proxy card?

A: You should contact either:

Thomas L. Osteraas, Secretary
Cogeneration Corporation of America
One Carlson Parkway, Suite 240
Minneapolis, MN 55447-4454

(612) 745-7900

or our proxy solicitor:

D.F. King & Co., Inc.

77 Water Street

New York, NY 10005

Banks and Brokers call:

(212) 269-5550

All others call toll-free:

(800) 848-3094

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TABLE OF CONTENTS

Summary.....................................................      1
The Companies.............................................      1
The Special Meeting.......................................      2
Record Date; Voting Power; Votes Required.................      2
Potential Benefits and Detriments of the Merger to
Unaffiliated Stockholders; Benefits to Insiders........      3
Recommendations of the Independent Directors Committee and
the Board of Directors.................................      3
Opinion of CogenAmerica's Financial Advisor...............      4
Terms of the Merger Agreement.............................      4
General................................................      4
Conditions to the Merger...............................      4
No Solicitation........................................      5
Termination............................................      5
Fees and Expenses......................................      5
Accounting Treatment......................................      6
Conflicts of Interests....................................      6
Board of Directors and Officers of CogenAmerica........      6
NRG....................................................      6
Regulatory Approvals......................................      6
Appraisal Rights..........................................      7
The Special Meeting.........................................      8
General...................................................      8
Proposals to be Considered at the Special Meeting.........      8
Record Date; Voting Power; Votes Required.................      8
Voting Procedures; Proxies................................      9
Historical Market Information...............................     10
Selected Consolidated Financial Data of CogenAmerica........     11
Proposal 1: The Merger......................................     13
Special Factors.............................................     13
Background of the Merger..................................     13
Purpose, Timing and Structure of the Merger...............     19
Reasons for the Merger....................................     20
Recommendations of the Independent Directors Committee and
the Board of Directors.................................     24
Opinion of Financial Advisor..............................     25
Perspective of NRG on the Fairness of the Merger..........     30
Plans for CogenAmerica After the Merger...................     31
Certain Effects of the Merger.............................     32
Unsolicited Offers From Third Parties.....................     32
Conflicts of Interest.....................................     33
Arrangements with NRG..................................     33
Arrangements Between Calpine and NRG...................     34
Directors and Officers of CogenAmerica.................     34
Severance Agreements for Officers......................     35
Indemnification........................................     35
Summary of Material Features of the Merger..................     37
The Merger................................................     37
General................................................     37

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Merger Consideration......................................................................         37
Payment for Shares........................................................................         37
Stock Options and Warrant.................................................................         37
Closing of Transfer Books.................................................................         37
Conditions to the Merger..................................................................         38
Representations and Warranties............................................................         39
Certain Covenants.........................................................................         39
No Solicitation of Transactions...........................................................         40
Termination...............................................................................         41
Termination Fee...........................................................................         42
Indemnification...........................................................................         42
Amendment and Waiver......................................................................         43
Expenses..................................................................................         43
Effective Time...............................................................................         43
Conversion of Common Stock...................................................................         43
Payment for Stock Options....................................................................         44
Conduct of Business Pending the Merger.......................................................         44
Regulatory Filings and Approvals.............................................................         44
Conditions to the Merger.....................................................................         45
Federal Income Tax Consequences of the Transaction...........................................         45
Financing of the Merger; Source of Funds.....................................................         45
Anticipated Accounting Treatment.............................................................         46
Appraisal Rights.............................................................................         46
Summary of Material Features of the Calpine/NRG Agreement......................................         50
Proposal 2: The Charter Amendment..............................................................         52
Summary of the Amendment.......................................................................         52
Management of CogenAmerica.....................................................................         52
Interest in Securities of CogenAmerica.........................................................         52
Certain Transactions in Common Stock and Stock Options.........................................         55
Expenses of the Transaction....................................................................         55
Independent Accountants........................................................................         55
Where You Can Find More Information............................................................         56
Incorporation of Certain Documents by Reference................................................         57
Shareholder Proposals..........................................................................         57
Other Matters..................................................................................         57
Appendix to the Proxy Statement................................................................         59
APPENDICES
APPENDIX A -- Agreement and Plan of Merger.....................................................        A-1
APPENDIX B -- Amendment to CogenAmerica Certificate of Incorporation...........................        B-1
APPENDIX C -- Opinion of Donaldson Lufkin & Jenrette Securities Corporation....................        C-1
APPENDIX D -- Text of Section 262 of the Delaware General Corporation Law......................        D-1

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SUMMARY

This summary highlights selected information from this proxy statement and
may not contain all of the information that is important to you. For a more
complete understanding of the merger and for a more complete description of the
legal terms of the merger, you should read this proxy statement carefully, as
well as the appendices to this proxy statement, including the merger agreement.
For additional information on CogenAmerica, see "Where You Can Find More
Information" (page 56).

THE COMPANIES

Cogeneration Corporation of America
One Carlson Parkway, Suite 240
Minneapolis, Minnesota 55447-4454
Telephone: (612) 745-7900

Cogeneration Corporation of America, a Delaware corporation, is an
independent power producer engaged primarily in the business of developing,
owning and managing the operation of cogeneration projects which produce
electricity and thermal energy for sale under long-term contracts with
industrial and commercial users and public utilities. CogenAmerica's current
project portfolio consists of (1) a 122 megawatt ("MW") cogeneration facility in
Parlin, New Jersey, (2) a 58 MW cogeneration facility in Newark, New Jersey, (3)
a 117 MW cogeneration facility in Morris, Illinois, (4) a 110 MW cogeneration
facility in Pryor, Oklahoma, (5) an 83% interest in two standby/peak shaving
facilities with an aggregate capacity of 22 MW in Philadelphia, Pennsylvania,
and (6) a 50% interest in a 150 MW cogeneration facility in Philadelphia,
Pennsylvania. Through its United Kingdom subsidiary called Puma, CogenAmerica
also designs and assembles diesel and natural gas fueled power generation
systems ranging in size from 5 kilowatts to 5 MW. The CogenAmerica common stock
trades on the The Nasdaq Stock Market under the symbol "CGCA".

Calpine Corporation
50 West San Fernando Street
San Jose, California 95113
Telephone: (408) 995-0505

Calpine Corporation, a Delaware corporation, is a leading independent power
company engaged in the development, acquisition, ownership and operation of
power generation facilities and the sale of electricity predominantly in the
United States.

Calpine East Acquisition Corp.
50 West San Fernando Street
San Jose, California 95113
Telephone: (408) 995-0505

Calpine East Acquisition Corp., a Delaware corporation ("Acquisition Sub"),
is currently a wholly-owned subsidiary of Calpine. Calpine formed Acquisition
Sub shortly before execution of the merger agreement for the purpose of carrying
out the merger. Immediately prior to the merger NRG will contribute to
Acquisition Sub approximately

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1.4 million shares of its CogenAmerica common stock in exchange for a 20%
interest in Acquisition Sub.

NRG Energy, Inc.
1221 Nicollet Mall, Suite 700
Minneapolis, Minnesota 55403-2445
Telephone: (612) 373-5300

NRG Energy, Inc., a Delaware corporation, is one of the world's leading
independent power producers, specializing in the development, construction,
operation, maintenance and ownership of low-cost, environmentally sensitive
power plants. Established in 1989 as a wholly owned subsidiary of Northern
States Power Company, NRG has a diversified energy portfolio of projects in the
United States, Europe, the Pacific Rim, and Latin America. NRG is involved in
approximately 15,000 MW of projects utilizing diverse fuel types including
natural and landfill gas, hydro and solid fuels such as coal, lignite, biomass
and refuse-derived fuel.

THE SPECIAL MEETING (PAGE 8)

The special meeting will be held on December 16, 1999 at 9:00 a.m., local
time, at The Marquette Hotel, Universe Room, 50th Floor, 710 Marquette Avenue,
Minneapolis, Minnesota. At the special meeting, stockholders will be asked to
consider and vote upon a proposal to approve and adopt the merger agreement and
a proposal to approve the amendment to CogenAmerica's certificate of
incorporation. The special meeting has been called by order of the CogenAmerica
Board of Directors.

RECORD DATE; VOTING POWER; VOTES REQUIRED (PAGE 8)

Holders of record of CogenAmerica common stock at the close of business on
November 12, 1999 are entitled to notice of and to vote at the special meeting.
As of that date, there were 6,857,269 shares of CogenAmerica common stock issued
and outstanding held by approximately 2,200 holders of record. Holders of record
of CogenAmerica common stock on the record date are entitled to one vote per
share on any matter that may properly come before the special meeting. The
quorum required to hold the special meeting is 60% of the shares of CogenAmerica
common stock entitled to vote at the meeting, present in person or by proxy. If
a quorum is present, the affirmative vote of the holders of more than 66 2/3% of
the outstanding shares of CogenAmerica common stock is required to approve and
adopt the merger agreement and the affirmative vote of the holders of more than
50% of the outstanding shares of CogenAmerica common stock is required to
approve the amendment to CogenAmerica's certificate of incorporation.

On the record date, NRG owned 3,106,612 shares of CogenAmerica common stock
or approximately 45.3% of the outstanding shares. Pursuant to the contribution
and stockholder agreement dated as of August 26, 1999 (the "Calpine/NRG
Agreement") between NRG and Calpine, NRG has granted its proxy to Calpine to
vote the CogenAmerica shares held by NRG for approval and adoption of the merger
agreement and the charter amendment.

If either proposal is not approved, the merger will not be completed,
CogenAmerica will remain a public company and the stockholders of CogenAmerica
will not have the right to receive $25.00 per share for the CogenAmerica common
stock. A stockholder who wishes to exercise appraisal rights under the Delaware
General Corporation Law

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("DGCL") must vote against or fail to vote for approval and adoption of the
merger agreement.

POTENTIAL BENEFITS AND DETRIMENTS OF THE MERGER TO UNAFFILIATED STOCKHOLDERS;
BENEFITS TO INSIDERS (PAGES 20, 32 AND 33)

The primary benefit of the merger to you is the opportunity to sell all of
your shares of CogenAmerica common stock at a cash price which represents a
substantial premium over historical trading prices. The merger consideration of
$25.00 per share in cash represents a premium of approximately 48.6% over the
average market price for CogenAmerica common stock for the 20 trading days
preceding the announcement of the execution of the merger agreement on August
27, 1999. As a result of the merger, however, you will not be entitled to
participate in future earnings or growth of CogenAmerica. In addition, you will
be required to recognize a taxable gain as a result of the merger if your cost
basis in your shares of CogenAmerica common stock is less than $25.00 per share.

Upon completion of the merger, Calpine will own 80% and NRG will own 20% of
the equity interests of CogenAmerica. As the stockholders of CogenAmerica,
Calpine and NRG will have complete control over the management and conduct of
CogenAmerica's business, all income generated by CogenAmerica and any future
increase in CogenAmerica's value. Similarly, Calpine and NRG will also bear the
risk of any losses incurred in the operation of CogenAmerica and any decrease in
the value of CogenAmerica. Calpine will have operating control over CogenAmerica
subject to certain limitations set forth in the Calpine/NRG Agreement.

Like the unaffiliated stockholders of CogenAmerica, the executive officers
and directors of CogenAmerica will have the right to receive $25.00 per share
for each of their shares of CogenAmerica common stock. In addition, the officers
and directors of CogenAmerica who hold options will have the right to receive
(a) the excess of $25.00 over the exercise price of each option multiplied by
(b) the number of shares of CogenAmerica common stock purchasable upon exercise
of the option (after giving effect to any acceleration of the option as a result
of the merger), net of withholding and applicable taxes.

At November 12, 1999, the executive officers and directors of CogenAmerica
beneficially owned 737,000 shares of CogenAmerica common stock, including
647,000 shares subject to options that will become exercisable as a result of
the merger, representing an aggregate cash payment to such persons upon
completion of the merger of $9,482,625. Because current NRG corporate policy
prohibits NRG employees from receiving the economic benefit of options granted
to them in their capacity as a director of an affiliated company, the three NRG
employees, who currently serve as directors of CogenAmerica and were previously
granted stock options in their capacity as directors of CogenAmerica, have
agreed to cancel their stock options. The three NRG employees who serve as
directors of CogenAmerica will receive no cash payment for cancellation of these
options.

RECOMMENDATIONS OF THE INDEPENDENT DIRECTORS COMMITTEE AND THE BOARD OF
DIRECTORS (PAGE 24)

Because NRG will retain a 20% equity interest in CogenAmerica after the
merger and certain directors of CogenAmerica are or were officers of NRG, the
Independent Directors

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Committee of the CogenAmerica Board of Directors reviewed and evaluated the
proposals to acquire CogenAmerica. At special meetings held on August 26, 1999,
the Independent Directors Committee and the Board of Directors of CogenAmerica
each unanimously determined that the merger is in furtherance of and consistent
with the long-term business strategies of CogenAmerica and is fair to and in the
best interest of the CogenAmerica stockholders (other than NRG). The
CogenAmerica Board of Directors unanimously recommends that you vote "FOR"
approval and adoption of the merger agreement and the charter amendment. You
should refer to the matters considered by the Independent Directors Committee
and the Board of Directors of CogenAmerica in determining whether to approve the
merger agreement, beginning at page 20.

OPINION OF COGENAMERICA'S FINANCIAL ADVISOR (PAGE 25)

Donaldson, Lufkin & Jenrette Securities Corporation ("DLJ"), a nationally
recognized investment banking firm, rendered an opinion, dated August 26, 1999
to the Independent Directors Committee of the CogenAmerica Board of Directors
that, as of such date, based upon and subject to the assumptions, limitations
and qualifications in the opinion, the consideration to be received by the
holders (other than NRG) of CogenAmerica common stock in the merger is fair to
the holders from a financial point of view. THE FULL TEXT OF THE WRITTEN OPINION
OF DLJ IS ATTACHED TO THIS PROXY STATEMENT AS APPENDIX C. YOU SHOULD READ THE
FAIRNESS OPINION OF DLJ IN ITS ENTIRETY.

TERMS OF THE MERGER AGREEMENT (PAGE 37)

The merger agreement is attached to this proxy statement as Appendix A. You
should read the merger agreement in its entirety. It is the legal document that
governs the merger.

General. The merger agreement provides that Acquisition Sub will be merged
into CogenAmerica and CogenAmerica will be the surviving corporation. As a
result of the merger, the stockholders of CogenAmerica will have the right to
receive $25.00 in cash, without interest, for each share of common stock that
they own, other than shares owned by CogenAmerica, Acquisition Sub or
CogenAmerica stockholders who exercise their appraisal rights.

Conditions to the Merger. The completion of the merger depends upon the
satisfaction of a number of conditions, including:

- approval of the merger agreement by the holders of more than 66 2/3% of
the outstanding shares of common stock;

- approval of the charter amendment by the holders of more than 50% of the
outstanding shares of CogenAmerica common stock;

- receipt of all necessary orders and consents of governmental authorities
and other persons and the expiration of any regulatory waiting periods;

- material accuracy of the representations and warranties of the parties
and the fulfillment of each party's promises contained in the merger
agreement;

- absence of any court or governmental entity rendering the merger illegal;
and

- absence of litigation having a material adverse effect on CogenAmerica.

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Each party may waive the satisfaction of any condition to its obligations
under the merger agreement, other than approval of the merger agreement and the
charter amendment by the CogenAmerica stockholders. EVEN IF THE COGENAMERICA
STOCKHOLDERS APPROVE THE MERGER AGREEMENT, THERE CAN BE NO ASSURANCE THAT THE
CONDITIONS TO THE OBLIGATIONS OF THE PARTIES TO COMPLETE THE MERGER WILL BE MET
OR WAIVED OR THAT THE MERGER WILL BE COMPLETED.

No Solicitation. Until completion or abandonment of the merger,
CogenAmerica and its affiliates are not permitted to solicit, initiate or
encourage any acquisition proposals from any other party. CogenAmerica may
respond to unsolicited acquisition proposals and enter into discussions if,
after receiving advice of counsel, the CogenAmerica Board of Directors
determines such response is necessary to fulfill its fiduciary obligations and
such proposal provides for consideration to CogenAmerica stockholders that is
superior to the consideration to CogenAmerica stockholders under the merger
agreement.

Termination. Either CogenAmerica or Calpine may terminate the merger
agreement under certain circumstances, including if:

- CogenAmerica and Calpine mutually consent in writing;

- the merger is not completed by the close of business on February 28,
2000 or, if the special meeting has not been held by February 28,
2000, then the merger is not completed by the close of business on
March 31, 2000;

- legal constraints or prohibitions prevent the completion of the
merger;

- CogenAmerica stockholders do not approve the merger agreement and
the charter amendment;

- the other party breaches in a material manner any of its
representations, warranties or covenants under the merger agreement
and the breach is not cured within 30 business days after notice; or

- CogenAmerica enters into or the CogenAmerica Board of Directors
approves an agreement for CogenAmerica to be acquired by another
party for consideration to CogenAmerica stockholders that is
superior to the consideration to CogenAmerica stockholders under the
merger agreement (a "Superior Proposal") so long as (a) CogenAmerica
notifies Calpine of the Superior Proposal, (b) Calpine has an
opportunity to respond, and (c) CogenAmerica pays Calpine a
termination fee of $7,500,000.

In addition, Calpine may terminate the merger agreement if the CogenAmerica
Board of Directors withdraws or modifies its recommendation that CogenAmerica
stockholders approve the merger agreement, or recommends an alternative
acquisition proposal.

Fees and Expenses. Each of CogenAmerica, Calpine and Acquisition Sub agreed
to pay its own fees and expenses. CogenAmerica will pay a termination fee of
$7,500,000 to Calpine if the merger agreement is terminated by reason of a
superior proposal permitting termination of the merger agreement or if
CogenAmerica is acquired by another party within 12 months following termination
of the merger agreement under certain circumstances specified in the merger
agreement.

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ACCOUNTING TREATMENT (PAGE 46)

CogenAmerica believes that the merger will be accounted for by Acquisition
Sub using the purchase method of accounting in accordance with generally
accepted accounting principles.

CONFLICTS OF INTERESTS (PAGE 33)

Board of Directors and Officers of CogenAmerica. Four members of the
CogenAmerica Board of Directors were, at the time the CogenAmerica Board of
Directors approved the merger agreement, officers of NRG. However, none of the
NRG officers on the Board of Directors were members of the Independent Directors
Committee. Because current NRG corporate policy prohibits NRG employees from
receiving the economic benefit of options granted to them in their capacity as a
director of an affiliated company, the NRG employees, who currently serve as
directors of CogenAmerica and were previously granted stock options in their
capacity as directors of CogenAmerica, have agreed to the cancellation of their
stock options. The NRG employees who serve as directors of CogenAmerica will
receive no cash payment for cancellation of these options. The officers of
CogenAmerica, including its President and Chief Executive Officer who is also a
director of CogenAmerica, own or have options to purchase a substantial number
of shares of CogenAmerica common stock. All three disinterested directors of
CogenAmerica who comprise the Independent Director Committee own or have options
to purchase a substantial number of shares of CogenAmerica common stock.

NRG. As of the close of business on November 12, 1999, NRG beneficially
owned 3,106,612 shares of CogenAmerica common stock which represents
approximately 45.3% of the outstanding shares. Pursuant to the Calpine/NRG
Agreement, NRG has agreed to contribute immediately prior to completion of the
merger part of its holdings (approximately 1.4 million shares of common stock)
to Acquisition Sub in exchange for a 20% interest in Acquisition Sub. NRG has
granted its proxy to Calpine to vote the CogenAmerica shares held by NRG for
approval and adoption of the merger agreement and the charter amendment at the
special meeting. In addition, NRG or its subsidiaries and CogenAmerica or its
subsidiaries are currently parties to agreements (the "Affiliate Agreements")
pursuant to which (1) NRG has agreed to offer to sell to CogenAmerica certain
independent power plants developed by NRG, (2) NRG has agreed to provide certain
management services to CogenAmerica and CogenAmerica has agreed to reimburse NRG
for its costs incurred to provide the management services, and (3) NRG has
agreed to manage the operation of independent power plants owned by CogenAmerica
in Morris, Illinois, and in Newark and Parlin, New Jersey, and CogenAmerica has
agreed to pay NRG certain management fees and reimburses NRG for its operating
costs. In connection with the completion of the merger, NRG and CogenAmerica
will terminate these agreements and exchange mutual general releases.

REGULATORY APPROVALS (PAGE 44)

CogenAmerica is required to make filings with or obtain approvals from
regulatory authorities in connection with the merger. These filings and
approvals include filings with the Securities and Exchange Commission (the
"SEC"), the Federal Trade Commission, the Department of Justice, the Federal
Energy Regulatory Commission ("FERC") and the New Jersey Department of
Environmental Protection. The filings with the SEC consist of this proxy
statement and a Schedule 13E-3 providing certain disclosures to

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CogenAmerica stockholders concerning the merger and the parties to the
transactions contemplated by the merger agreement. An application and notice was
filed with the Federal Trade Commission and the Department of Justice as
required by the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended
(the "HSR Act") on October 13, 1999. An application and notice was filed with
the FERC on September 17, 1999. The requisite filings under the New Jersey
Industrial Site Recovery Act were made on August 31, 1999.

APPRAISAL RIGHTS (PAGE 46)

Any stockholder of CogenAmerica who does not vote in favor of the proposal
to approve the merger agreement and who strictly complies with the applicable
provisions of Section 262 of the DGCL has appraisal rights to receive cash for
the "fair value" for such holder's shares of CogenAmerica common stock, which
may be more than, the same as, or less than the agreed consideration of $25.00
per share. "Fair value" will be determined based on the value of the shares
immediately before completion of the merger without any appreciation or
depreciation in anticipation of the merger and may be more than, the same or
less than the merger consideration of $25.00 per share. To exercise appraisal
rights with respect to the merger, you must follow the required procedures
precisely, which include the requirement to give written notice to CogenAmerica
before the special meeting of your intent to demand payment. A stockholder who
wishes to exercise appraisal rights under the DGCL must vote against or fail to
vote for approval and adoption of the merger agreement. The provisions of
Section 262 of the DGCL are attached to this proxy statement as Appendix D.

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THE SPECIAL MEETING

GENERAL

This proxy statement is furnished in connection with the solicitation of
proxies by the CogenAmerica Board of Directors for the special meeting of
Stockholders of CogenAmerica to be held on December 16, 1999 at 9:00 a.m., local
time, at The Marquette Hotel, Universe Room, 50th Floor, 710 Marquette Avenue,
Minneapolis, Minnesota and at any adjournments thereof.

PROPOSALS TO BE CONSIDERED AT THE SPECIAL MEETING

At the special meeting, the CogenAmerica stockholders will be asked to
consider and vote upon:

- a proposal to approve and adopt the merger agreement,

- a proposal to approve and adopt the charter amendment, and

- consider and act upon such other matters as may properly come before the
special meeting.

The merger is conditioned on the approval of the merger agreement and the
charter amendment by the CogenAmerica stockholders. Subject to the receipt of
regulatory approvals, approval by the CogenAmerica stockholders and satisfaction
of other conditions, the merger agreement provides for the merger of Acquisition
Sub with and into CogenAmerica. If the proposed merger is completed, each issued
and outstanding share of CogenAmerica common stock at the effective time of the
merger (other than shares owned by CogenAmerica, by Acquisition Sub and by
stockholders who exercise their appraisal rights) will be converted into the
right to receive $25.00 in cash. The charter amendment enables NRG to transfer
and contribute to Acquisition Sub immediately prior to completion of the merger
approximately 1.4 million shares of its CogenAmerica common stock in exchange
for a 20% equity interest in Acquisition Sub. After completion of the merger,
CogenAmerica will be owned 80% by Calpine and 20% by NRG.

RECORD DATE; VOTING POWER; VOTES REQUIRED

Only holders of record of CogenAmerica common stock on the record date are
entitled to notice of and to vote at the special meeting. As of November 12,
1999, there were 6,857,269 shares of CogenAmerica common stock issued and
outstanding and held by approximately 2,200 holders of record. Holders of record
of CogenAmerica common stock on the record date are entitled to one vote per
share on any matter that may properly come before the special meeting. The
quorum required to hold the special meeting is 60% of the shares of CogenAmerica
common stock entitled to vote at the meeting, present in person or by proxy. If
a quorum is present, the affirmative vote of the holders of more than 66 2/3% of
the total voting power of the shares of CogenAmerica common stock entitled to
vote is required to approve and adopt the merger agreement, and the affirmative
vote of the holders of more than 50% of the shares of CogenAmerica common stock
entitled to vote is required to approve the charter amendment.

On the record date, NRG owned 3,106,612 shares of CogenAmerica common stock
or approximately 45.3% of the outstanding shares. Pursuant to the Calpine/NRG
Agreement, NRG granted its proxy to Calpine to vote the CogenAmerica shares held
by NRG for

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approval and adoption of the merger agreement and the charter amendment.
Accordingly, CogenAmerica needs the affirmative vote of an additional 1,464,901
shares to approve and adopt the merger agreement and 322,023 shares to approve
the charter amendment.

VOTING PROCEDURES; PROXIES

If you fail to vote, or vote to abstain, it will have the same legal effect
as a vote cast against the proposals. Your broker and, in many cases, your
nominee will not have discretionary power to vote on the proposals to be
presented at the special meeting. Accordingly, you should instruct your broker
or nominee how to vote. A broker non-vote will have the same effect as a vote
against the proposals.

If there are insufficient votes to approve the proposals at the special
meeting and if you authorized your shares to be voted in favor of the
adjournment of the special meeting in order to provide additional time to
solicit additional proxies in favor of the proposals, your shares will be voted
to adjourn the special meeting in order to solicit additional proxies in favor
of the proposals. If the special meeting is adjourned or postponed for any
purpose, at any subsequent reconvening of the special meeting, your proxy will
be voted in the same manner as it would have been voted at the original
convening of the meeting unless you withdraw or revoke your proxy. Your proxy
may be voted this way even though it may have been voted on the same or any
other matter at a previous meeting.

Under Delaware law, if you do not vote in favor of the proposals and comply
with certain notice requirements and other procedures, you will have the right
to dissent and to be paid cash for the "fair value" of your shares as finally
determined under such procedures. This payment may be more, the same as or less
than the consideration to be received by other CogenAmerica stockholders under
the terms of the merger agreement. If you fail to follow such procedures
precisely, you may lose your appraisal rights. See "Appraisal Rights."

Each stockholder who signs and returns a proxy in the form enclosed with
this proxy statement may revoke the same at any time prior to its use by giving
notice of such revocation to CogenAmerica in writing or in person at the special
meeting. Signing and returning a later dated proxy in the form enclosed with
this proxy statement will revoke a prior proxy. Presence at the special meeting
of a stockholder who has signed a proxy does not alone revoke that proxy. Unless
so revoked, all of the shares represented by each proxy will be voted at the
special meeting and at any adjournments thereof. IF NO INSTRUCTIONS ARE
INDICATED, SUCH PROXIES WILL BE VOTED FOR THE PROPOSALS TO APPROVE AND ADOPT THE
MERGER AGREEMENT AND THE CHARTER AMENDMENT, FOR POSTPONEMENT OR ADJOURNING OF
THE SPECIAL MEETING FOR THE PURPOSE OF SOLICITING ADDITIONAL PROXIES FOR
APPROVAL AND ADOPTION OF THE MERGER AGREEMENT, THE CHARTER AMENDMENT AND, IN THE
DISCRETION OF THE PERSONS NAMED ON THE PROXY, ON SUCH OTHER MATTERS AS MAY
PROPERLY BE PRESENTED AT THE SPECIAL MEETING.

The cost of preparing, assembling and mailing this proxy statement, the
notice, the proxy card and other material which may be sent to the stockholders
will be borne by CogenAmerica. In addition, directors, officers and regular
employees of CogenAmerica and its subsidiaries, at no additional compensation,
may solicit proxies by telephone, telegram or in person. Upon request,
CogenAmerica will reimburse brokers and other persons holding shares for the
benefit of others for their expenses in forwarding proxies and accompanying
material and in obtaining authorization from beneficial owners of CogenAmerica
common stock to give proxies. CogenAmerica has also retained D.F.

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King & Co., Inc. to assist in the solicitation of proxies. The proxy solicitor
will receive customary fees and expense reimbursement for its services.

In order to assure the presence of the necessary quorum at the special
meeting, please sign and mail the enclosed proxy promptly in the envelope
provided. No postage is required if mailed within the United States. The signing
of the proxy will not prevent you from attending the meeting and voting in
person, should you so desire.

HISTORICAL MARKET INFORMATION

CogenAmerica common stock is currently traded on Nasdaq National Market
tier of The Nasdaq Stock Market under the symbol "CGCA". From March 1997 to
November 1997, the CogenAmerica common stock was traded on the Nasdaq SmallCap
Market. Prior to March 1997, the CogenAmerica common stock was not listed on an
exchange or on The Nasdaq Stock Market, but traded from time to time on the pink
sheets and on the OTC Bulletin Board. The following table sets forth the high
and low sales prices for each quarterly period since 1997 from the quotations
published by Nasdaq-Amex Online. Such prices may have reflected inter-dealer
prices, without retail mark-ups, mark-downs or commissions, and may not
necessarily represent actual transactions.

HIGH        LOW
-------    -------

1999:
First Quarter...............................................    $ 9.375    $  8.00
Second Quarter..............................................    $ 14.50    $ 8.125
Third Quarter...............................................    $24.438    $ 14.75
Fourth Quarter (through November 8, 1999)...................    $ 24.50    $23.813
1998:
First Quarter...............................................    $19.531    $15.125
Second Quarter..............................................    $ 18.25    $13.313
Third Quarter...............................................    $ 15.00    $  7.25
Fourth Quarter..............................................    $ 10.00    $ 7.625
1997:
First Quarter...............................................    $ 13.75    $ 11.25
Second Quarter..............................................    $ 16.00    $11.125
Third Quarter...............................................    $ 21.00    $ 14.25
Fourth Quarter..............................................    $22.375    $ 18.00

On August 26, 1999, the last trading day prior to announcement of the
execution of the merger agreement, the closing sale price per share of
CogenAmerica common stock on The Nasdaq Stock Market as published by Nasdaq-Amex
Online was $16.813. On November 8, 1999, the closing sale price per share of
CogenAmerica common stock was $24.438. The high and low bid quotations during
the period from August 26, 1999 (the date the merger was signed) through
November 8, 1999 were $24.50 and $16.813, respectively.

CogenAmerica has not paid any cash dividends on its common stock.

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SELECTED CONSOLIDATED FINANCIAL DATA OF COGENAMERICA

The following table shows summarized historical financial data for
CogenAmerica. This information is based on historical information presented in
CogenAmerica's filings with the SEC. You should read all of the summary
financial information in the table in connection with this historical financial
information. This historical financial information is incorporated into this
proxy statement by reference. See "Where You Can Find More Information" on page
56. Effective December 31, 1996, CogenAmerica changed its fiscal year end from
June 30 to December 31.

SIX MONTHS   SIX MONTHS       YEAR           YEAR        SIX MONTHS      YEAR       YEAR       YEAR
ENDED        ENDED         ENDED          ENDED          ENDED        ENDED      ENDED      ENDED
JUNE 30,     JUNE 30,    DECEMBER 31,   DECEMBER 31,   DECEMBER 31,   JUNE 30,   JUNE 30,   JUNE 30,
1999         1998          1998           1997         1996(1)        1996       1995       1994
----------   ----------   ------------   ------------   ------------   --------   --------   --------
(DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)

STATEMENT OF OPERATIONS
DATA:
Revenues:
Energy....................   $ 45,302     $ 21,801      $ 52,216       $ 43,210       $ 21,669     $ 66,623   $ 74,455   $ 62,647
Equipment sales and
services.................      7,096        8,334        19,342         19,415         15,607       25,344     19,639     24,304
Rental....................         --        1,481         2,438          2,179          1,062        1,895      2,362      5,372
Development fees and
other....................         --           --            --             --          1,578        2,685      5,791     14,266
Total..................     52,398       31,616        73,996         64,804         39,916       96,547    102,247    106,589
Income (loss) before
extraordinary item.......     12,816        4,052         8,002         23,352          4,780      (17,713)   (40,919)   (16,501)
Net income (loss)(4)......     12,816        4,052         8,002         23,352          6,423      (17,713)   (40,919)   (16,501)
Basic earnings (loss) per
share(2):
Before extraordinary
Item...................   $   1.87     $   0.59      $   1.17       $   3.59       $   0.75     $  (4.24)  $ (11.02)  $  (4.45)
Extraordinary item.......         --           --            --             --           0.25           --         --         --
After extraordinary
Item...................   $   1.87     $   0.59      $   1.17       $   3.59       $   1.00     $  (4.24)  $ (11.02)  $  (4.45)
Diluted earnings (loss)
per share(2):
Before extraordinary
Item...................   $   1.85     $   0.58      $   1.15       $   3.48       $   0.74     $  (4.24)  $ (11.02)  $  (4.45)
Extraordinary item.......         --           --            --             --           0.25           --         --         --
After extraordinary
Item...................   $   1.85     $   0.58      $   1.15       $   3.48       $   0.99     $  (4.24)  $ (11.02)  $  (4.45)
BALANCE SHEET DATA:
Total assets...........   $341,612     $263,178      $318,674       $227,894       $173,624     $178,162   $189,748   $237,816
Long-term debt, net of
current maturities:
Loans due NRG............     40,123        4,439        36,123          4,439         14,388       96,929         --         --
Nonrecourse long-term
debt(3)................    186,810      201,077       189,848        143,697        143,972       60,415      3,405     60,310
Recourse long-term
debt...................     45,225       25,000        45,225         46,323          6,339        6,374         --      7,073
Total..................    272,158      230,516       271,196        194,459        164,699      163,718      3,405     67,383
COMPUTATION OF RATIO OF
EARNINGS TO FIXED
CHARGES(5):
Pre-tax income (loss) from
continuing operation.....   $ 20,623     $  6,814      $ 12,880       $  2,898       $  4,512     $(18,176)  $(38,239)  $(14,588)
Undistributed income of
equity investees less
than 50% owned...........      2,247        2,646         4,784            105            162           61         --         --
Capitalized interest......         --        1,979         3,858            674             --           --         --         --
Fixed charges of 50% owned
person...................        970           --            --             --             --           --         --         --
Pre-tax income (loss) from
continuing operations
before adjustments for
minority interests in
consolidated subsidiaries
or income or loss from
equity investees.........   $ 17,406     $  2,189      $  4,238       $  2,119       $  4,350     $(18,237)  $(38,239)  $(14,588)
Fixed charges:
Interest expense and
amortization of debt
expense................     11,310        7,039        15,855         14,768          7,681       18,646     20,583     18,013
Capitalized interest.....         --        1,979         3,858            674             --           --         --         --
Fixed charges of 50%
owned person...........        970
Rentals at one-third.....         --           27            54             59            168          268        433        436
Total fixed charges.......   $ 12,280     $  9,045      $ 19,767       $ 15,501       $  7,849     $ 18,914   $ 21,016   $ 18,449

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SIX MONTHS   SIX MONTHS       YEAR           YEAR        SIX MONTHS      YEAR       YEAR       YEAR
ENDED        ENDED         ENDED          ENDED          ENDED        ENDED      ENDED      ENDED
JUNE 30,     JUNE 30,    DECEMBER 31,   DECEMBER 31,   DECEMBER 31,   JUNE 30,   JUNE 30,   JUNE 30,
1999         1998          1998           1997         1996(1)        1996       1995       1994
----------   ----------   ------------   ------------   ------------   --------   --------   --------
(DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)

Pre-tax income (loss) from
continuing operations
before adjustments for
minority interests in
consolidated subsidiaries
or income or loss from
equity investees plus
fixed charges, less
preferred stock dividend
requirements of
consolidated
subsidiaries.............   $ 29,686     $ 11,234      $ 24,005       $ 17,620       $ 12,199     $    677   $(17,223)  $  3,861
Ratio of earnings to fixed
charges..................        2.4          1.2           1.2            1.1            1.6           --         --         --
COMPUTATION OF BOOK VALUE
PER SHARE:
Stockholders' equity
(deficit)................   $ 16,601     $   (124)     $ (3,813)      $ (4,202)      $(30,513)    $(37,573)  $(40,758)  $    136
Weighted average shares
outstanding -- diluted...   $  6,942     $  6,999      $  6,966       $  6,725       $  6,463     $  4,182   $  3,712   $  3,712
Book value per share......   $   2.39     $  (0.02)     $   0.55       $  (0.62)      $  (4.72)    $  (8.98)  $ (10.98)  $   0.04

---------------

(1) Effective July 1, 1996, CogenAmerica changed its fiscal year-end from June
30 to December 31.

(2) Net income (loss) per share has been restated for all periods presented to
reflect the common shares issued under the terms of the plan of
reorganization for O'Brien Environmental Energy, Inc. (now called
Cogeneration Corporation of America) which emerged from reorganization under
Chapter 11 of the Federal bankruptcy laws on April 30, 1996.

(3) Amount at June 30, 1995 excludes $60,310 of long-term project financing
which was included in current liabilities due to a default under the debt
agreement.

(4) Amount for 1997 reflects a net tax benefit of $20,454 resulting from the
reduction of a tax valuation allowance. See Note 16 of CogenAmerica's
Consolidated Financial Statements incorporated by reference into this proxy
statement.

(5) For the purposes of determining the ratio of earnings to fixed charges,
"earnings" consists of income (loss) before income tax expense and
extraordinary item plus fixed charges less undistributed equity in earnings
of less than 50% owned investees and capitalized interest. "Fixed charges"
consist of interest (whether expensed or capitalized) plus amortization of
deferred financing costs and one-third of rental expense (this portion is
considered to be representative of the interest factor). Earnings were
insufficient to cover fixed charges for the fiscal year ended June 30, 1994,
1995 and 1996 in the amounts of $14.6 million, $38.2 million and $18.2
million, respectively. For the six months ended June 30, 1999, pre-tax
income (loss) from continuing operations includes a one-time gain in the
amount of $14,536 representing the fair value of additional ownership
interest in the Grays Ferry Cogeneration Partnership resulting from
settlement of litigation.

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PROPOSAL 1: THE MERGER

SPECIAL FACTORS

BACKGROUND OF THE MERGER

CogenAmerica's predecessor, O'Brien Environmental Energy, Inc., filed for
protection under Chapter 11 of the Federal bankruptcy laws on September 28,
1994. NRG proposed a plan of reorganization that was approved by the Bankruptcy
Court and O'Brien emerged from bankruptcy on April 30, 1996 under the name NRG
Generating (U.S.) Inc. ("NRG Generating") which subsequently changed its name to
Cogeneration Corporation of America. Under the reorganization plan, NRG advanced
NRG Generating $71.2 million under loan agreements, purchased approximately
41.86% of the NRG Generating common stock for approximately $21.2 million,
purchased certain subsidiaries of NRG Generating for $7.5 million and funded a
cash distribution to the former O'Brien stockholders totaling $7.5 million. The
former O'Brien stockholders also retained the remaining common stock or
approximately 58.14% of the then outstanding shares that were publicly traded.
In addition, as part of the reorganization plan, NRG and NRG Generating entered
into a co-investment agreement under which NRG agreed to offer NRG Generating
ownership interests in certain power projects that NRG initially developed or
had the right under contract to acquire from a third party and a management
services agreement under which NRG agreed to provide, at its cost, management
and support services. Pursuant to the co-investment agreement, CogenAmerica
acquired from NRG the Pryor, Oklahoma plant for $23.9 million in 1998 and the
Morris, Illinois plant for a development fee of $4.8 million paid to NRG plus
assumption of liabilities related to the project in 1997. Because of NRG's
substantial ownership of CogenAmerica and the number of NRG representatives on
the CogenAmerica Board of Directors, the new bylaws for CogenAmerica approved as
part of the bankruptcy reorganization plan established an Independent Directors
Committee of the Board of Directors that is responsible for making all decisions
for CogenAmerica in connection with the co-investment agreement and the
management services agreement with NRG. Under the bylaws, the Independent
Directors Committee must consist of at least two disinterested directors.
Currently, the Independent Directors Committee is comprised of the three
disinterested directors on the CogenAmerica Board of Directors, Mark Liddell,
Lawrence I. Littman, and Charles J. Thayer.

From January 26, 1999 through May 13, 1999, CogenAmerica received
indications of interest from four independent power companies, including Calpine
and Bidder A, to acquire 100% of the equity interests of CogenAmerica. These
indications of interest were not solicited by the Company or, to the Company's
knowledge, by any person acting on behalf of the Company or NRG. The indications
of interest were at prices that ranged from $16.00 to $19.00 per share in cash.
During this period, the range of the public trading prices for CogenAmerica
common stock was $8.00 to $13.00 per share.

Based on the level of interest from the four parties and the significant
premium in their indications of interest over the then market price of the
CogenAmerica common stock, management informed the CogenAmerica Board of
Directors of the indications of interest and sought advice from financial and
legal advisors on how best to proceed in considering the offers. Management
contacted DLJ since DLJ had previously served as CogenAmerica's investment
banker and was familiar with CogenAmerica's business and the independent power
and public utility industries. Management also sought advice from Kaplan,
Strangis and Kaplan, P.A. ("KSK"), a Minneapolis, Minnesota law firm

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experienced in acquisition and merger transactions. Copies of the indications of
interest from the four parties were also provided to the directors of
CogenAmerica. Based upon the advice of DLJ and KSK, and after the directors had
reviewed that advice and considered their alternatives, a meeting of the
CogenAmerica Board of Directors was scheduled for May 20, 1999.

At the meeting of the CogenAmerica Board of Directors on May 20, 1999, the
directors reviewed the indications of interest, counsel explained the fiduciary
duties of the CogenAmerica Board of Directors under the circumstances and DLJ
provided a presentation on current industry conditions and the strategic
alternatives available to the CogenAmerica Board of Directors. The CogenAmerica
Board of Directors determined that a sale of 100% of the equity interests of
CogenAmerica should be explored, approved the engagement of DLJ and KSK, and
authorized DLJ to assist management and counsel in the conduct of a process for
the sale of CogenAmerica.

Following the May 20, 1999 CogenAmerica Board of Directors meeting, DLJ
assisted management in preparing an "Information Package" to provide interested
parties with relevant information on CogenAmerica and its business, assets,
operations and personnel. The Information Package consisted of (i) the Annual
Report of CogenAmerica for the year ended December 31, 1998; (ii) the Quarterly
Report on form 10-Q of CogenAmerica for the Quarter ended March 31, 1999; (iii)
the Proxy Statement dated April 26, 1999 for CogenAmerica's annual stockholders
meeting; and (iv) a financial model based on management's internal projections
for each of CogenAmerica's existing six plants and consolidated statements for
CogenAmerica for the period from January 1, 1999 to December 31, 2009. From May
25, 1999 through June 4, 1999, DLJ contacted 13 parties in the independent power
industry or the public utility industry that had the financial resources to
acquire CogenAmerica and that had been active in acquiring generation capacity.
Nine of the 13 parties indicated an interest in reviewing the Information
Package for CogenAmerica, including Calpine and Bidder A. CogenAmerica executed
confidentiality agreements with each of the eight bidders that had not
previously executed a confidentiality agreement. After each bidder had signed a
confidentiality agreement, it received an Information Package. After receiving
the Information Package, the nine parties were requested to submit preliminary
indications of interest on June 11, 1999. Seven parties submitted preliminary
indications of interest, while two parties declined to make a submission. The
preliminary indications of interest ranged from a low of $15.09 per share to a
high of $24.00 per share for 100% of the equity interests in CogenAmerica. On
June 11, 1999, DLJ received an unsolicited indication of interest from an
investment fund for an acquisition of CogenAmerica.

On June 21, 1999, the CogenAmerica Board of Directors met to consider the
preliminary indications of interest. DLJ summarized the current status of the
solicitation process and described the terms of each preliminary indication of
interest. DLJ also advised the CogenAmerica Board of Directors that an
investment fund had approached DLJ with an unsolicited indication of interest in
acquiring CogenAmerica. The CogenAmerica Board of Directors decided to continue
the sale process with the five highest bidders and the investment fund upon its
execution of a confidentiality agreement. Continuation of the sale process
included allowing the six bidders access to CogenAmerica's management and
records for purposes of conducting due diligence. The CogenAmerica Board of
Directors established July 13, 1999 as the date on which the six remaining
parties would be required to submit firm offers. The CogenAmerica Board of

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Directors also decided to invite the highest bidder from the June 11 round of
bids to make a preemptive bid.

The due diligence process included an opportunity to review of the
corporate, legal and financial records of CogenAmerica, including material
contracts, and a management presentation with an opportunity to ask questions of
management. Each prospective bidder was also provided forms of merger agreement
with CogenAmerica and a stockholder agreement with NRG that had been prepared by
CogenAmerica's outside counsel with the input of management and NRG, and
approved by CogenAmerica and NRG. The highest bidder in the June 11, 1999 round
of bids declined to submit a preemptive offer. On July 13, 1999, the six parties
submitted their bids and comments on the proposed forms of merger agreement and
stockholder agreement. The cash bids ranged from a low of $18.50 per share to a
high of $23.00 per share. All of the bids also required CogenAmerica and NRG to
terminate the Affiliate Agreements.

On July 15, 1999, the CogenAmerica Board of Directors met to consider the
bids. DLJ summarized the current status of the solicitation process and
described the terms of each bid. Counsel reviewed the changes proposed by the
bidders to the forms of merger agreement and stockholder agreement. In this
round, Calpine and Bidder A were the highest bidders with bids of $22.50 per
share and $23.00 per share, respectively. The CogenAmerica Board of Directors
determined that negotiations should proceed with Calpine and Bidder A on the
terms of the merger agreement and the stockholder agreement and that each party
should complete its due diligence.

Later that day, Calpine and Bidder A were notified that they were the two
final bidders in the sale process and that their bids were virtually equal.
Subsequently, representatives of NRG indicated to CogenAmerica's management and
outside counsel that NRG might not be able to sell all of its equity interest in
CogenAmerica in light of the pending merger transaction involving NRG's parent
company, Northern States Power Company ("NSP") which effectively limits the
disposition of assets by parties to the merger. As a result, meetings of the
Independent Directors Committee and the Board of Directors of CogenAmerica were
scheduled for July 22, 1999.

A meeting of the Independent Directors Committee was held by telephone on
July 22, 1999 followed by a meeting of the CogenAmerica Board of Directors. DLJ
briefed the independent directors on the status of discussions with the
remaining two bidders. Counsel apprised the Independent Directors Committee of
the issue that NRG had raised and that resolution of the issue might require a
different transaction structure. Counsel also updated the Independent Directors
Committee on the progress of negotiations with NRG on the terms of an agreement
pursuant to which the various contracts with NRG and its subsidiaries would be
terminated in the event of a sale of CogenAmerica. The Independent Directors
Committee and the Board of Directors of CogenAmerica determined that the new
concerns regarding the transaction structure should be resolved as quickly as
possible and that the sale process with the remaining two bidders should
proceed.

On July 27, 1999, representatives from Calpine and its counsel met with
representatives of CogenAmerica and its management to negotiate Calpine's
proposed changes to the form of merger agreement. Thereafter, NRG's
representatives, with CogenAmerica's management and representatives present,
negotiated with Calpine its proposed changes to the form of stockholder
agreement with NRG. On July 28, 1999, representatives from Bidder A and its
counsel met with representatives of CogenAmerica and its management to negotiate
Bidder A's proposed changes to the form of merger agreement. Thereafter,

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NRG's representatives, with CogenAmerica's management and representatives
present, negotiated with Bidder A its proposed changes to the form of
stockholder agreement with NRG. At each meeting, counsel for CogenAmerica
informed Calpine and Bidder A of the possibility of an alternative transaction
structure. Both parties were willing to proceed with the sale process while a
viable transaction structure was developed. Based on the negotiating sessions
over the definitive agreements, CogenAmerica delivered to Calpine and Bidder A
on or about July 30, 1999 revised forms of the merger agreement and stockholder
agreement that were acceptable to CogenAmerica. The parties were requested to
submit revised bids and any revisions to the merger agreement and the
stockholder agreement by August 3, 1999.

On August 3, 1999, both Calpine and Bidder A submitted new bids, including
a mark-up of the merger agreement and stockholder agreement that each party was
willing to execute. Calpine initially offered $23.52 per share in cash for 100%
of the equity interests of CogenAmerica and Bidder A offered $24.00 per share in
cash for 100% of the equity interests in CogenAmerica. A meeting of the
CogenAmerica Board of Directors was held on August 4, 1999 to consider the bids.
Shortly before the meeting, Calpine increased its bid to $24.52 per share in
cash. At the meeting, DLJ summarized the sale process to date and confirmed its
view that either party had the requisite financial resources available to
consummate the transaction. Counsel described the material changes proposed by
Calpine and Bidder A to the merger agreement and stockholder agreement. NRG's
representative informed the CogenAmerica Board of Directors that the transaction
would have to be restructured to meet NRG's needs if a transaction were to
proceed. The CogenAmerica Board of Directors then determined that the
Independent Directors Committee should be given full control of the sale process
because NRG might have interests that differ from those of CogenAmerica and the
unaffiliated stockholders. The Independent Directors Committee met briefly and
requested that NRG outline the proposed structure of the transaction before
requiring the two remaining bidders to submit final bids. The full CogenAmerica
Board of Directors meeting then reconvened and the CogenAmerica Board of
Directors was apprised of the determinations by the Independent Directors
Committee.

On August 6, 1999, the Independent Directors Committee held a meeting to
determine how to proceed. Counsel reviewed the outline of the possible
transaction structure developed by NRG's representatives, which remained subject
to approval by NRG's board of directors and advised the committee members that
an outline of the proposed transaction could be provided to the two bidders
later that day. The outline proposed that the winning bidder would have the
right to acquire 80% of the equity interests in CogenAmerica and NRG would
retain a 20% equity interest in CogenAmerica. Counsel confirmed that, as a
result of the restructuring of the proposed transaction, NRG did in fact have
interests that differed from those of CogenAmerica and the unaffiliated
stockholders.

Later that day, the two bidders received the outline of the proposed
structure of the transaction. Each of the bidders was also advised that it would
have an opportunity to discuss and negotiate the proposed terms of a possible
transaction with NRG and that each bidder would be required to resubmit its bid
for CogenAmerica by the close of business on August 10, 1999. On Monday, August
9, 1999, each party separately reviewed and negotiated the terms of a possible
transaction with NRG representatives. Representatives of DLJ and KSK were
present during such discussions.

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At the close of business on August 10, 1999, both Calpine and Bidder A
resubmitted their respective bids. Each party provided a mark-up of the merger
agreement previously provided by CogenAmerica to reflect the changes required by
it and a mark-up of the outline of the possible transaction structure. Neither
party changed the price per share in its bid; Calpine offered $24.52 per share
in cash and Bidder A offered $24.00 per share in cash for 80% of the equity
interests in CogenAmerica.

On August 11 and 12, 1999, the Independent Directors Committee held
telephonic meetings. At each meeting, DLJ reported on the rebids received from
the two bidders and counsel summarized the changes to the merger agreement
proposed by each bidder and reported the status of the continuing discussions
between NRG and each bidder. Following the meetings, at the direction of the
Independent Directors Committee, DLJ communicated with both bidders
contemporaneously. Bidder A was informed that it needed to increase its bid and
Calpine was advised that it needed to accept the merger agreement as proposed by
CogenAmerica and the outline as acceptable to NRG's management which remained
subject to approval by NRG's board of directors.

In the evening of August 12, 1999, Calpine delivered a letter to
CogenAmerica increasing its offer to $24.77 per share in cash, accepting the
merger agreement as proposed by CogenAmerica, accepting the terms acceptable to
NRG's management, which remained subject to approval by NRG's board of
directors, and indicating its willingness to negotiate and finalize definitive
documents on such terms. Calpine stated that its offer required an exclusive
period through 5:00 p.m. Eastern Time on August 17, 1999 to finalize the
documentation with NRG.

On August 13, 1999, commencing at approximately 6:00 a.m., Central Time,
the Independent Directors Committee held a telephonic meeting. The Independent
Directors Committee received reports from KSK and DLJ on the events that
transpired the previous evening. At approximately 7:30 a.m., Central Time,
Bidder A increased its offer to $24.77 per share, confirmed its acceptance of
the merger agreement as proposed by CogenAmerica, and requested a two week
exclusivity period to conclude negotiation of a definitive agreement with NRG on
the terms acceptable to NRG's management subject to NRG's Board approval. A
representative of Bidder A verbally indicated to DLJ that Bidder A did not
expect to increase its offer above $24.77 per share.

The Independent Directors Committee reconvened its meeting at approximately
7:45 a.m., Central Time, on August 13, 1999. DLJ informed the independent
directors of the August 13, 1999 letter from Bidder A and the conversation in
which Bidder A indicated that it did not expect to increase its offer. After
further discussion and considering the recommendations of DLJ and KSK, the
Independent Directors Committee authorized DLJ to contact Calpine. DLJ was
directed to inform Calpine that the Committee would accept Calpine's proposal
with the following modifications: (1) the price would be $25.00 per share, (2)
the merger agreement would be changed to provide for a one-step merger rather
than a tender offer followed by a second-step merger, and (3) any debt of
CogenAmerica that could be accelerated as a result of the merger, including the
debt owed to NRG, would be repaid upon completion of the merger.

Calpine requested that the message be in writing and signed on behalf of
the Independent Directors Committee. Counsel for CogenAmerica then prepared a
letter dated August 13, 1999 (the "August 13 Exclusivity Letter") incorporating
the terms approved by the Independent Directors Committee. The August 13
Exclusivity Letter was signed on behalf of the Independent Directors Committee
and transmitted to Calpine via facsimile.

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Calpine accepted the proposal and returned the August 13 Exclusivity Letter
countersigned by Calpine. With the consent of Calpine, DLJ advised Bidder A that
Calpine had been given an exclusive period to conclude the documentation and no
further communications would occur with Bidder A during the exclusive period.

CogenAmerica's counsel then informed NRG of the decision by the Independent
Directors Committee and provided NRG with a copy of the August 13 Exclusivity
Letter and a revised merger agreement reflecting the change in the structure to
a one-step merger from a tender offer followed by a second-step merger.

During the morning on August 16, 1999, Calpine and its counsel met with
CogenAmerica and its counsel to finalize the merger agreement. Commencing in the
afternoon of August 16, 1999 and continuing through August 19, 1999, Calpine,
NRG and their respective counsel discussed the terms of the proposed Calpine/NRG
Agreement.

On August 19, 1999, Bidder A sent by facsimile a letter addressed to the
Board of Directors of NRG, the Independent Directors Committee and the
CogenAmerica Board of Directors. The letter affirmed the interest of Bidder A to
proceed with a transaction and increased its bid to $24.99 per share. Because
CogenAmerica was bound by the exclusivity terms of the August 13 Exclusivity
Letter, no response to Bidder A's letter was made by CogenAmerica or its
officers, directors, employees, agents or representatives.

On August 19, 1999, a Calpine representative advised CogenAmerica and NRG
that the Calpine board of directors approved the merger agreement and the
Calpine/NRG Agreement.

On August 25, 1999, an NRG representative advised CogenAmerica and Calpine
that the NRG board of directors approved the Calpine/NRG Agreement. Meetings of
the Independent Directors Committee and Board of Directors of CogenAmerica were
called for 9:00 a.m. and 12:00 noon, respectively, on August 26, 1999.

On August 26, 1999, commencing at approximately 9:00 a.m., Central Time,
the Independent Directors Committee held a meeting. All independent directors
were present in person as were representatives of DLJ and KSK. At the request of
the independent directors, a representative of O'Melveny & Myers ("O&M"),
counsel to the Independent Directors Committee, attended by telephone.
Representatives of KSK briefed the Independent Directors Committee regarding
their fiduciary duties and the terms of the merger agreement, the Calpine/NRG
Agreement, the agreement between CogenAmerica and NRG (the "Termination
Agreement") terminating the Affiliate Agreements upon completion of the merger,
and an agreement among CogenAmerica, Calpine and NRG (the "Cooperation
Agreement") pursuant to which the parties agree to cooperate with each other in
the preparation of this Proxy Statement and the Schedule 13E-3 that are required
to be filed with the SEC. Copies of the final agreements were available to the
independent directors and were reviewed during the meeting. Representatives of
DLJ briefed the Independent Directors Committee on the sale process and the
bases for DLJ's fairness opinion. DLJ also delivered its executed fairness
opinion addressed to the Independent Directors Committee. The independent
directors also reviewed the benefits and detriments of the proposed merger to
the unaffiliated stockholders of CogenAmerica. The factors considered by the
Independent Directors Committee are discussed below in the section called
"Reasons for the Merger." After considering these factors and the advice of its
financial and legal advisors, the Independent Directors Committee unanimously
approved the merger agreement, the charter amendment, the Calpine/NRG Agreement,
the Termination Agreement and the Cooperation Agreement, and unanimously recom-

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mended that the CogenAmerica Board of Directors approve the merger agreement,
the charter amendment, the Calpine/NRG Agreement and the Cooperation Agreement.

Following conclusion of the meeting of the Independent Directors Committee
and commencing at approximately 12:00 noon, Central Time, the CogenAmerica Board
of Directors convened its meeting in Minneapolis, Minnesota to consider the
transactions contemplated by the merger agreement. All directors of CogenAmerica
were present in person, except for Craig A. Mataczynski and Michael O'Sullivan
who participated by telephone. KSK briefed the CogenAmerica Board of Directors
on the fiduciary duties of the directors and the terms of the merger agreement,
the Calpine/NRG Agreement, the Termination Agreement and the Cooperation
Agreement. Copies of the agreements were available to the directors at the
meeting and were reviewed during the presentation by KSK on the agreements.
Representatives of DLJ reviewed the sale process and the bases for DLJ's
fairness opinion. DLJ also confirmed that it had delivered its executed fairness
opinion to the Independent Directors Committee and that the entire CogenAmerica
Board of Directors was entitled to rely on the opinion. The directors also
reviewed the benefits and detriments of the proposed merger to the unaffiliated
stockholders of CogenAmerica. The factors considered by the CogenAmerica Board
of Directors are discussed below in the section called "Reasons for the Merger."
After considering these factors and the advice of the financial and legal
advisors to CogenAmerica, the CogenAmerica Board of Directors unanimously
approved the merger agreement, the charter amendment, the Calpine/NRG Agreement
and the Cooperation Agreement, and unanimously recommended that the CogenAmerica
stockholders approve the merger agreement and the charter amendment.

After the close of business on August 26, 1999, CogenAmerica executed and
delivered the merger agreement to Calpine, the Cooperation Agreement to Calpine
and NRG, and the Termination Agreement to NRG. Contemporaneously, Calpine
executed and delivered the merger agreement to CogenAmerica, the Cooperation
Agreement to CogenAmerica and NRG, and the Calpine/NRG Agreement to NRG.
Contemporaneously, NRG executed and delivered the Termination Agreement to
CogenAmerica, the Cooperation Agreement to CogenAmerica and Calpine, and the
Calpine/NRG Agreement to Calpine. Press releases announcing the transactions
contemplated by the merger agreement and Calpine/NRG Agreement were issued on
the morning of August 27, 1999.

PURPOSE, TIMING AND STRUCTURE OF THE MERGER

The purpose for the merger is to enable Calpine to acquire 80% and NRG to
retain 20% of the entire equity interests of CogenAmerica in a transaction that
provides the public stockholders of CogenAmerica and NRG, to the extent its
equity interest in CogenAmerica is not being retained, with the opportunity to
sell all of their CogenAmerica common stock at a price which represents a
substantial premium over market prices in effect immediately prior to the
announcement of the merger.

The timing of the execution of the merger agreement resulted from an
extensive sale process conducted by CogenAmerica after it had received four
indications of interest for the acquisition of CogenAmerica at significant
premiums to the then market price of CogenAmerica common stock. In addition, the
market for the sale of independent power company assets has recently been
favorable to sellers of such assets as significant consolidation is occurring in
the independent power industry. In addition, the Independent Directors Committee
and the Board of Directors of CogenAmerica concluded that sufficient additional
capital for CogenAmerica to make acquisitions and expand its business would be
difficult to obtain given CogenAmerica's current leverage and current stock
price

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and that the development of new plants, so called "green field" projects, would
be time consuming and involved significant risk that they would not be completed
after substantial management time and expense had been invested in the projects.

The transaction was structured to achieve both (1) the requirement by NRG
that it retain a 20% interest in CogenAmerica after completion of the merger and
(2) the requirement of Calpine that it acquire the remaining 80% equity interest
in CogenAmerica in a single transaction, while at the same time facilitating a
direct cash payment at a premium price to all holders of CogenAmerica common
stock (other than shares held by CogenAmerica, by Acquisition Sub or by
stockholders who properly exercise their appraisal rights). CogenAmerica also
wished to present its stockholders with a simple transaction that treats equally
all unaffiliated stockholders.

Acquisition Sub is currently a wholly owned subsidiary of Calpine.
Immediately prior to the completion of the merger, NRG will contribute shares of
CogenAmerica common stock to Acquisition Sub which will enable NRG to retain a
20% equity interest in CogenAmerica after completion of the merger. Calpine
formed Acquisition Sub shortly before execution of the merger agreement for the
sole purpose of carrying out the merger.

REASONS FOR THE MERGER

The Independent Directors Committee and the Board of Directors of
CogenAmerica have determined that the merger is substantively fair to the
unaffiliated stockholders of CogenAmerica for the reasons listed in factors (1)
through (8) below, and is procedurally fair to the unaffiliated stockholders of
CogenAmerica for the reasons listed in factors (1), (7), (9) and (10) below and
because (i) the Independent Directors Committee consisting only of board members
representing solely the interest of CogenAmerica and the stockholders other than
NRG approved the transaction, (ii) the Independent Directors Committee was
advised by independent legal counsel retained to negotiate on behalf of
CogenAmerica and the stockholders other than NRG, (iii) the Independent
Directors Committee retained, and received advice from, DLJ as its independent
financial advisor which assisted in the conduct of a sale process and in the
evaluation of the proposed transaction, (iv) the $25.00 per share price and the
other terms and conditions of the merger agreement resulted from an extensive
sale process and arms'-length bargaining between representatives of the
Independent Directors Committee and Calpine and their advisors. See "Special
Factors -- Recommendations of the Independent Directors Committee and the Board
of Directors." The Independent Directors Committee and the Board of Directors of
CogenAmerica unanimously recommend that the CogenAmerica stockholders approve
and adopt the merger agreement and the charter amendment. In reaching these
conclusions, the Independent Directors Committee and the Board of Directors of
CogenAmerica considered and analyzed a number of factors. All of the material
factors considered by the CogenAmerica Board of Directors are described below.

1. Competitive Sale Process. The merger consideration of $25.00 per share
was arrived at after an intense and competitive sale process. During the sale
process, 13 parties were contacted of which seven parties submitted preliminary
indications of interest ranging from $15.09 to $24.00 per share for 100% of the
equity interests of CogenAmerica. Six parties were invited to conduct extensive
due diligence after which firm bids were submitted. The bids ranged from $18.50
to $23.00 per share for 100% of the equity interests in CogenAmerica. The two
highest bidders, Calpine and Bidder A, were invited to conduct on-site plant
visits and to negotiate the terms of the definitive documents. Calpine

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and Bidder A subsequently submitted final bids of $25.00 and $24.77,
respectively. Both the Independent Directors Committee and the Board of
Directors of CogenAmerica determined that the manner in which the sale process
was conducted was a very important factor in concluding that the price resulting
from that process was fair to the unaffiliated stockholders.

2. Premium over Current Market Price. On August 25, 1999, the trading day
immediately preceding the meetings of the Independent Directors Committee and
the Board of Directors of CogenAmerica, the closing sales price for CogenAmerica
common stock was $16.75 per share. The merger consideration of $25.00 per share
represented a premium of 49.3% over the closing market price on August 25, 1999.
Both the Independent Directors Committee and the Board of Directors of
CogenAmerica concluded that the significant premium over the current market
price was a very important factor in favor of the transaction and determining
the merger consideration was fair to the unaffiliated stockholders.

3. Premium over Historical Market Price. The merger consideration of $25.00
per share represented a significant premium over the historical market price of
CogenAmerica common stock. The following premiums over historical market price
were considered to be very important factors to both the Independent Directors
Committee and the Board of Directors of CogenAmerica in favor of the transaction
and in their determination that the merger consideration was fair to the
unaffiliated stockholders:

PREMIUM
OVER HISTORICAL
DATE OR PERIOD TO MEASURE PREMIUM                   MARKET PRICE
---------------------------------                  ---------------

January 26, 1999 (the first date a bidder met formally with
NRG to express its interest in an acquisition
transaction)..............................................         170.3%
May 20, 1999 (the date the CogenAmerica Board of Directors
determined to explore strategic alternatives).............         102.0%
July 29, 1999 (four weeks prior to the approval of the
merger agreement by the Independent Directors Committee
and the Board of Directors of CogenAmerica)...............          40.8%
August 19, 1999 (one week prior to the approval of the
merger agreement by the Independent Directors Committee
and the Board of Directors of CogenAmerica)...............          50.4%

In addition, both the Independent Directors Committee and the Board of Directors
of CogenAmerica considered very important the fact that the historical daily
trading volume of CogenAmerica common stock was relatively small, it being in
the range of 12,000 to 13,000 shares or approximately 0.2% of the outstanding
shares. The merger would enable all unaffiliated stockholders to sell their
shares for cash without any depressing effect that the sale of a considerable
number of shares might have on the market price of the CogenAmerica common
stock.

4. Presentation and Opinion of DLJ. Both the Independent Directors
Committee and the Board of Directors of CogenAmerica considered very important
the presentation made by DLJ at their meetings on August 26, 1999 and DLJ's
fairness opinion addressed to the Independent Directors Committee in determining
that the merger was fair to the unaffiliated stockholders. For a discussion of
the DLJ presentation, see the caption entitled "Opinion of Financial Advisor"
below and see Appendix C for a copy of the full text of

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the written opinion of DLJ dated August 26, 1999 which sets forth assumptions
made, matters considered and limitations on the review undertaken in connection
with the opinion.

5. Going Concern Value. As part of its presentation to the Independent
Directors Committee and the Board of Directors of CogenAmerica on August 26,
1999, DLJ presented a discounted cash flow analysis of the value of CogenAmerica
as a going concern. Depending on the assumptions for discount rate and multiple
of earnings before interest, taxes, depreciation and amortization for the
terminal value, the discounted cash flow analysis indicated an implied value of
CogenAmerica common stock in the range of $9.62 per share to $22.39 per share.
Although the Independent Directors Committee and the Board of Directors of
CogenAmerica considered the going concern value (as expressed by the discounted
cash flow analysis by DLJ) as an important factor supporting the fairness of the
merger consideration to the unaffiliated stockholders, this factor was somewhat
less important than the other four factors discussed above.

6. Future Prospects as a Public Company. Both the Independent Directors
Committee and the Board of Directors of CogenAmerica considered the future
prospects of CogenAmerica as an independent public company. In order for
CogenAmerica to continue its growth, CogenAmerica had to acquire or develop
additional independent power plants. CogenAmerica would require additional
capital to provide the financial resources necessary for the acquisition or
development of new projects. Due to the current high leverage of CogenAmerica,
additional debt might not be available or, if available, would be at high
interest rates. An analysis by management indicated that the sale of
CogenAmerica common stock at a price below $20.00 per share would be dilutive of
future earnings and, therefore, not a viable alternative to raising capital.
Also, due to the low earnings multiple for CogenAmerica and the competitive
prices for independent power plants, it would be difficult for CogenAmerica to
make acquisitions using its stock that would be accretive to future earnings.
The current competitive market for existing independent power plants made
acquisitions of existing plants expensive. The development of new plants,
so-called "green field" projects, required a substantial amount of time and
investment without any assurance that CogenAmerica would be awarded the project.
Based on CogenAmerica's capital constraints and risks of future expansion, both
the Independent Directors Committee and the Board of Directors of CogenAmerica
considered this factor to be important in determining that the merger was the
best alternative for the unaffiliated stockholders.

7. Right to Terminate Merger Agreement. After following certain procedures
and paying Calpine a termination fee of $7,500,000, CogenAmerica has the right
to terminate the merger agreement in order to accept a superior takeover
proposal from a third party. This so-called "fiduciary out" provision is
described in "Summary of Material Features of the Merger -- Termination" below.
The Calpine/NRG Agreement provides that the agreement terminates in the event
the merger agreement terminates. As a result, if CogenAmerica received a
superior takeover proposal from a third party, it would be able to terminate the
merger agreement by following the requisite procedures, and NRG would be able to
enter into an agreement with the third party on terms comparable to the Calpine/
NRG Agreement. This would enable the Independent Directors Committee and the
Board of Directors of CogenAmerica to accept a takeover proposal that provides
more value to the unaffiliated stockholders of CogenAmerica. Both the
Independent Directors Committee and the Board of Directors of CogenAmerica
considered the fiduciary out provision of the

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merger agreement a significant factor in determining the merger was fair to the
unaffiliated stockholders.

8. Financial Ability of Calpine. Calpine has the financial ability to
complete the merger and support CogenAmerica's future business operations. The
merger agreement is not conditioned on financing by Calpine. Both the
Independent Directors Committee and the Board of Directors of CogenAmerica
considered the financial ability of Calpine to fund the merger consideration to
be a significant factor in approving the merger agreement.

9. Appraisal Rights. Stockholders of CogenAmerica who do not support the
merger or are dissatisfied with the consideration to be received by the holders
of CogenAmerica common stock are able to obtain "fair value" for their shares if
they properly exercise their appraisal rights under the DGCL. Both the
Independent Directors Committee and the Board of Directors of CogenAmerica
considered the ability of unaffiliated stockholders to exercise their appraisal
rights as a favorable factor, but not as important as the factors enumerated
above in paragraphs 1 through 8.

10. Stockholder Vote. The proposed merger is not conditioned on the
approval of at least a majority of unaffiliated shareholders. Pursuant to the
Calpine/NRG Agreement, NRG has granted its proxy to Calpine to vote the
CogenAmerica shares held by NRG for approval and adoption of the merger
agreement and the charter amendment. Since the proposed merger requires the
approval of more than 66 2/3% of the outstanding shares of CogenAmerica common
stock and NRG owns approximately 45.3% of the outstanding CogenAmerica common
stock, unaffiliated shareholders owning an aggregate of approximately 39.1% of
the outstanding CogenAmerica common stock held by unaffiliated shareholders need
to vote in favor of the proposals to enable the proposed merger to proceed.
Based on the fact that Calpine would not proceed with the transaction unless NRG
agreed to grant its proxy to Calpine to vote NRG's CogenAmerica shares in favor
of the merger agreement and the charter amendment at the special meeting and
that, as discussed in paragraph 7 above, the Calpine/NRG Agreement would
terminate in the event the CogenAmerica Board of Directors exercised its
"fiduciary out" to terminate the merger agreement in order to accept a superior
takeover proposal from another party, the Independent Directors Committee and
the Board of Directors of CogenAmerica did not consider the lack of a vote of
the majority of the unaffiliated shareholders as an important factor and
concluded that the proposed transaction is procedurally fair despite the absence
of a requirement that a majority of the unaffiliated shareholders approve the
proposed merger.

11. Net Book Value. The Independent Directors Committee and the Board of
Directors of CogenAmerica did not consider the net book value of CogenAmerica as
a relevant factor in its determination.

12. Liquidation Value. Neither the Independent Directors Committee nor the
Board of Directors of CogenAmerica considered the liquidation value of
CogenAmerica as a relevant factor in its determination. A liquidation of the
assets would result in CogenAmerica paying taxes on the gain from the sale of
its assets. Therefore, the net proceeds from the sale of its assets would be
reduced by taxes and transaction costs before any distribution could be made to
stockholders.

13. Price Paid by NRG for CogenAmerica Common Stock. NRG facilitated the
reorganization of CogenAmerica's predecessor in 1996 under Chapter 11 of the
Federal Bankruptcy Laws by contributing an aggregate of $21.2 million to the
predecessor in

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exchange for 2,710,357 shares of the predecessor's common stock representing
approximately 41.86% of the outstanding shares of CogenAmerica common stock
after giving effect to such issuance. The price per share of CogenAmerica common
stock paid by NRG was $3.27. Since the operations of CogenAmerica have
substantially improved since that time, including the addition of two plants
after the 1996 reorganization, neither the Independent Directors Committee nor
the Board of Directors of CogenAmerica considered the price paid by NRG for its
shares of CogenAmerica common stock as a relevant factor in its determination.

In view of the variety of factors considered in connection with its
evaluation of the merger, the Independent Directors Committee and the Board of
Directors of CogenAmerica found it impracticable to, and did not, quantify, rank
or otherwise assign relative weights to the reasons for the merger described
above or determine that any reason was of particular importance in reaching its
determination that the merger is fair to and in the best interest of
CogenAmerica stockholders (other than NRG), except that the factors enumerated
in paragraphs 1 through 4 above were the most important, the factors enumerated
in paragraphs 5 and 6 above were important, the factors in paragraphs 7 and 8
were also important but less significant than the first six factors, the factor
enumerated in paragraph 9 was less significant than the first eight factors, the
factor enumerated in paragraph 10 was not important, and the factors enumerated
in paragraphs 11 through 13 were not relevant. The Independent Directors
Committee and the Board of Directors of CogenAmerica view their recommendations
as being based upon their judgment, in light of the totality of the information
presented and considered, as summarized in the reasons for the merger described
above, and the overall effect of the merger on CogenAmerica's stockholders
compared to continuing the business of CogenAmerica in the ordinary course or
seeking other potential parties to effect a business combination.

RECOMMENDATIONS OF THE INDEPENDENT DIRECTORS COMMITTEE AND THE BOARD OF
DIRECTORS

The Independent Directors Committee is a standing committee of the
CogenAmerica Board of Directors that is comprised of three disinterested
directors. The purpose of the Independent Directors Committee is to consider and
act upon matters where the interests of NRG, as the principal stockholder and
whose officers constitute four members of the CogenAmerica Board of Directors,
may be in conflict with the interests of the unaffiliated stockholders of
CogenAmerica. When it became apparent in the sale process undertaken by
CogenAmerica that NRG would be treated differently from the unaffiliated
stockholders of CogenAmerica, the Independent Directors Committee took over
control of the sale process. The Independent Directors Committee then retained
financial and legal advisors to assist it in the sale process and the other
matters related to the transactions contemplated by the merger agreement. On
August 26, 1999, the Independent Directors Committee determined that the merger
was in the best interests of CogenAmerica and was fair to CogenAmerica
stockholders (other than NRG). Accordingly, the Independent Directors Committee
unanimously approved the merger agreement, the charter amendment, the
Termination Agreement, the Calpine/NRG Agreement and the Cooperation Agreement,
and recommended that the CogenAmerica Board of Directors approve the merger
agreement, the charter amendment and the Cooperation Agreement after receiving
reports from its financial and legal advisors, including reports on the sale
process, the terms of the operative documents and the valuation analysis by DLJ,
and the written opinion from DLJ that, as of its date and subject to the
assumptions, limitations and qualifications set forth in the written opinion,
the consideration to be paid to the CogenAmerica

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stockholders (other than NRG) in the merger was fair from a financial point of
view. The Independent Directors Committee took such actions for the reasons set
forth above under the caption "Reasons for the Merger."

Following the meeting of the Independent Directors Committee, the
CogenAmerica Board of Directors held a meeting on August 26, 1999 to consider
the transactions contemplated by the merger agreement. The CogenAmerica Board of
Directors received reports from financial and legal advisors for CogenAmerica.
The reports included a review of the sale process, a discussion of the terms of
the operative agreements and the valuation analysis by DLJ. DLJ also provided
the directors with a copy of the opinion of DLJ addressed to the Independent
Directors Committee that, as of its date and subject to the assumptions,
limitations and qualifications set forth in the written opinion, the
consideration to be paid to the stockholders other than NRG in the merger was
fair from a financial point of view, and DLJ indicated that the directors were
entitled to rely on the opinion. The Independent Directors Committee also
informed the CogenAmerica Board of Directors that it had unanimously approved
the merger agreement, the charter amendment, the Termination Agreement, the
Calpine/NRG Agreement and the Cooperation Agreement, and unanimously recommended
that the CogenAmerica Board of Directors approve the merger agreement, the
charter amendment and the Cooperation Agreement. Based on these reports and
recommendations and for the reasons set forth above under the caption "Reasons
for the Merger," the CogenAmerica Board of Directors also determined that the
merger was in the best interests of CogenAmerica and was fair to the
unaffiliated stockholders of CogenAmerica. The CogenAmerica Board of Directors
unanimously approved the merger agreement, the charter amendment, the
Calpine/NRG Agreement and the Cooperation Agreement and recommended that the
CogenAmerica stockholders approve the merger agreement and the charter
amendment.

THE INDEPENDENT DIRECTORS COMMITTEE AND THE BOARD OF DIRECTORS OF
COGENAMERICA HAVE UNANIMOUSLY APPROVED THE MERGER AGREEMENT AND THE CHARTER
AMENDMENT, AND THE COGENAMERICA BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT
THE COGENAMERICA STOCKHOLDERS VOTE FOR APPROVAL AND ADOPTION OF THE MERGER
AGREEMENT AND THE CHARTER AMENDMENT.

OPINION OF FINANCIAL ADVISOR

CogenAmerica asked DLJ, in its role as financial advisor to CogenAmerica,
to render an opinion to the Independent Directors Committee of CogenAmerica as
to the fairness, from a financial point of view, to the holders of CogenAmerica
common stock, other than NRG, of the consideration to be received by such
holders in the merger. On August 26, 1999, DLJ delivered to the Independent
Directors Committee its written opinion to the effect that, as of such date,
based on and subject to the assumptions, limitations and qualifications set
forth in such written opinion, the consideration to be received in the merger by
the holders of CogenAmerica common stock, other than NRG, was fair to such
holders from a financial point of view.

THE FULL TEXT OF DLJ'S OPINION IS ATTACHED AS APPENDIX C TO THIS PROXY
STATEMENT. THE SUMMARY OF DLJ'S OPINION SET FORTH IN THIS PROXY STATEMENT IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO THE FULL TEXT OF DLJ'S OPINION.
COGENAMERICA STOCKHOLDERS ARE URGED TO READ DLJ'S OPINION CAREFULLY AND IN ITS
ENTIRETY FOR THE PROCEDURES FOLLOWED, ASSUMPTIONS MADE, OTHER MATTERS CONSIDERED
AND LIMITS OF THE REVIEW BY DLJ IN CONNECTION WITH SUCH OPINION.

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DLJ PREPARED ITS OPINION FOR THE INDEPENDENT DIRECTORS COMMITTEE SOLELY
WITH RESPECT TO THE FAIRNESS FROM A FINANCIAL POINT OF VIEW OF THE CONSIDERATION
TO BE RECEIVED IN THE MERGER BY HOLDERS OF COGENAMERICA COMMON STOCK, OTHER THAN
NRG, AS OF THE DATE THEREOF. DLJ EXPRESSED NO OPINION AS TO THE PRICES AT WHICH
COGENAMERICA COMMON STOCK WOULD ACTUALLY TRADE AT ANY TIME AND DOES NOT ADDRESS
THE RELATIVE MERITS OF THE MERGER AND THE OTHER BUSINESS STRATEGIES CONSIDERED
BY THE INDEPENDENT DIRECTORS COMMITTEE NOR DOES IT ADDRESS THE INDEPENDENT
DIRECTORS COMMITTEE'S DECISION TO PROCEED WITH THE MERGER. DLJ'S OPINION DOES
NOT ADDRESS ANY OTHER ASPECT OF THE MERGER NOR DOES IT CONSTITUTE A
RECOMMENDATION TO ANY COGENAMERICA STOCKHOLDER AS TO HOW TO VOTE ON THE MERGER
AND SHOULD NOT BE RELIED UPON BY ANY STOCKHOLDER AS SUCH.

CogenAmerica selected DLJ as its financial advisor because DLJ is an
internationally recognized investment banking firm that has substantial
experience providing strategic advisory services. DLJ was not retained as an
advisor or agent to the stockholders of CogenAmerica or any other person. As
part of its investment banking business, DLJ is regularly engaged in the
valuation of businesses and securities in connection with mergers, acquisitions,
underwritings, sales and distributions of listed and unlisted securities,
private placements and valuations for corporate and other purposes. CogenAmerica
did not impose any restrictions or limitations upon DLJ with respect to the
investigations made or the procedures followed by DLJ in rendering its opinion.
For purposes of rendering its opinion, DLJ among other things, reviewed the
Agreement and Plan of Merger and the company letter, dated August 26, 1999, and
the Calpine/NRG Agreement, also dated August 26, 1999, which sets forth the
essential terms and conditions upon which NRG would be able to sell its
CogenAmerica common stock. DLJ also reviewed certain financial and other
business information that was publicly available or furnished by CogenAmerica,
including information provided during discussions with management, for recent
years and interim periods to date. Included in the information provided during
discussions with management were certain internal financial forecasts and
projections of the Company for the period beginning January 1, 1999 and ending
December 31, 2009 prepared by the management of the Company. DLJ met with the
management of CogenAmerica to review and discuss such information and the
Company's business, operations, assets, financial condition and future
prospects.

In addition, DLJ reviewed the historical stock prices and trading volumes
of CogenAmerica common stock, reviewed prices and premiums paid in certain other
business combinations and conducted such other financial studies, analyses and
investigations as DLJ deemed appropriate for purposes of rendering its opinion.

In rendering its opinion, DLJ assumed and relied upon without independent
verification the accuracy and completeness of all of the financial and other
information that was available to it from public sources, that was provided to
it by CogenAmerica, or its representatives, or that was otherwise reviewed by
DLJ. With respect to the financial projections and assumptions supplied to DLJ,
DLJ assumed that they were reasonably prepared on bases reflecting the best
currently available estimates and judgments of the management of CogenAmerica as
to the future operating and financial performance of CogenAmerica. DLJ expressed
no opinion with respect to such projections, forecasts and analyses or the
assumptions upon which they were based. DLJ did not make any independent
valuation or appraisal of the assets or liabilities of CogenAmerica and did not
make any independent verification of the information reviewed by DLJ. DLJ was
not furnished with any such valuations or appraisals. DLJ's opinion was
necessarily based on economic, market, financial and other conditions as they
existed on, and on the

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information made available to DLJ as of, the date of its opinion. DLJ states in
its opinion that, although subsequent developments may affect its opinion, DLJ
does not have any obligation to update, revise or reaffirm its opinion.

The following is a summary of the financial analyses presented by DLJ to
the Independent Directors Committee on August 26, 1999 in connection with the
preparation of DLJ's opinion.

Common Stock Trading History. DLJ examined the historical closing prices of
CogenAmerica common stock from August 20, 1998 to August 23, 1999. During this
time period, CogenAmerica common stock reached a high of $18.13 per share and a
low of $7.94 per share. DLJ also examined the historical trading range of
CogenAmerica common stock from August 20, 1998 to August 23, 1999 relative to an
independent power producer index made up of The AES Corporation, Calpine
Corporation, MidAmerican Energy Holdings Company, Trigen Energy Corporation and
CogenAmerica. This information was presented solely to provide the Independent
Directors Committee with background information on the stock price of
CogenAmerica over the periods indicated.

Premiums Paid Analysis. DLJ determined the premium over the common stock
trading prices for one day, one week and four weeks prior to the announcement
date in all merger and acquisition transactions of U.S. public companies ranging
from $250 million to $750 million in size announced between January 1, 1996 and
August 20, 1999. DLJ obtained information for this analysis from Securities Data
Corp. DLJ analyzed the high, low and median of the premiums paid one day, one
week and four weeks prior to the announcement date. The median premiums for the
selected transactions over the common stock trading prices for one day, one week
and four weeks prior to the announcement date were 23.3%, 29.3% and 36.7%,
respectively. Applying the median premiums to the closing price of CogenAmerica
one day, one week and four weeks prior to the announcement date, DLJ estimated a
value per share of CogenAmerica common stock ranging from $21.42 to $24.61.

Comparable Publicly Traded Company Analysis. As part of its analysis, DLJ
compared the market values and trading multiples of CogenAmerica with that of
the following publicly traded independent power companies:

1. The AES Corporation

2. Calpine Corporation

3. MidAmerican Energy Holdings Company (formerly CalEnergy Company, Inc.),
and

4. Trigen Energy Corporation.

In examining these comparable companies, DLJ calculated the enterprise value of
each company as a multiple of its respective: LTM revenue; LTM EBITDA and LTM
EBIT. LTM means last reported twelve months. EBITDA means earnings before
interest expense, income taxes, depreciation and amortization. EBIT means
earnings before interest expense and income taxes. DLJ also calculated the
equity value of each company as a multiple of its respective: LTM net income;
and projected net income for the calendar year 1999. The enterprise value of a
company is equal to the value of its fully-diluted common equity plus debt and
the liquidation value of outstanding preferred stock, if any, minus cash and the
value of certain other assets, including minority interests in other entities.
Projected net income for the calendar year 1999 was obtained from First Call
estimates.

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For the purpose of this analysis, DLJ calculated EBITDA and EBIT to include
equity in income/loss of affiliates, and calculated enterprise value to include
investment in unconsolidated affiliates.

DLJ's analysis of the comparable companies yielded the following: revenue
multiples for the LTM ended June 30, 1999 ranging from 1.8x to 8.3x; EBITDA
multiples for the LTM ended June 30, 1999 ranging from 7.9x to 16.7x; EBIT
multiples for the LTM ended June 30, 1999 ranging from 14.1x to 24.8x; net
income multiples for the LTM ended June 30, 1999 ranging from 9.7x to 41.6x; and
projected net income multiples for the calendar year 1999 ranging from 14.0x to
34.0x. Based on an analysis of this data and CogenAmerica's results for
comparable periods, DLJ estimated a value per share of CogenAmerica common stock
ranging from $16.10 to $34.40.

These companies were selected by DLJ because they are in the same business
as CogenAmerica, which is the independent power business, and because they have
publicly traded securities. These companies comprise all of the independent
power companies which have publicly traded securities. However, no company
utilized in the comparable public company analysis is identical to CogenAmerica.
Accordingly, an analysis of the results of the foregoing necessarily involves
complex considerations and judgments concerning differences in financial and
operating characteristics of CogenAmerica and other factors that could affect
the public trading value of the companies to which it is being compared. In
evaluating the comparable companies, DLJ made judgments and assumptions with
regard to industry performance, general business, economic, market and financial
conditions and other matters, many of which are beyond the control of
CogenAmerica, such as the impact of competition on CogenAmerica and the industry
generally, industry growth and the assumed absence of any adverse material
change in the financial conditions and prospects of CogenAmerica or the industry
or in the financial markets in general. Mathematical analysis (such as
determining the mean or median) is not, in itself, a meaningful method of using
comparable company data.

Precedent Merger and Acquisition Transaction Analysis. DLJ analyzed
acquisition multiples paid in the acquisition of Sithe Energies by Marubeni
Corporation. This was the most comparable acquisition of a publicly traded
independent power company occurring prior to August 26, 1999. DLJ's analysis of
this comparable transaction yielded the following: (i) a revenue multiple for
the LTM ended September 30, 1995 of 3.3x; (ii) an EBITDA multiple for the LTM
ended September 30, 1995 of 10.4x; (iii) an EBIT multiple for the LTM ended
September 30, 1995 of 13.7x; and (iv) a net income multiple for the LTM ended
September 30, 1995 of 29.2x. Based on an analysis of this data and
CogenAmerica's results for comparable periods, DLJ estimated a value per share
of CogenAmerica common stock ranging from $20.81 to $32.80.

Using publicly available information, DLJ also reviewed certain
acquisitions involving the sale of generation assets by various independent
power companies and public utilities conducted over the year to date period
beginning January 1, 1999. In examining these transactions, DLJ analyzed the
enterprise value of the acquired assets as a multiple of their net generating
capacity. DLJ applied the high, low, median and average of these multiples to
CogenAmerica's net generating capacity to obtain an enterprise value, and equity
value per share. DLJ's analysis yielded an enterprise value multiple range of
$147/kW to $955/kW. Based on an analysis of this data and CogenAmerica's net
generating capacity, DLJ estimated a valuation range of CogenAmerica common
stock with a high end of $27.78 per share. The other end of the range was deemed
not meaningful due to CogenAmerica's relatively high enterprise value to net
generating capacity compared to the

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sample transactions that were examined by DLJ. No transaction utilized as a
comparison in the analysis of selected precedent transactions is identical to
the merger in both timing and size. Accordingly, an analysis of the results of
the foregoing necessarily involves complex considerations and judgments
concerning differences in financial and operating characteristics of
CogenAmerica and other factors that would affect the acquisition value of the
companies to which it is being compared. In evaluating the precedent
transactions, DLJ made judgments and assumptions with regard to industry
performance, global business, economic, market and financial conditions and
other matters, many of which are beyond the control of CogenAmerica, such as the
impact of competition on CogenAmerica and the industry generally, industry
growth and the assumed absence of any adverse material change in the financial
conditions and prospects of CogenAmerica or the industry or the financial
markets in general. Mathematical analysis (such as determining the mean or
median) is not, in itself, a meaningful method of using precedent transactions
data.

Discounted Cash Flow ("DCF") Analysis. DLJ also performed a DCF analysis of
the projected cash flows of CogenAmerica for the fiscal years ending December
31, 2000 through December 31, 2009, using projections and growth assumptions
provided by the management of CogenAmerica. The DCFs for CogenAmerica were
estimated using discount rates ranging from 9% to 11%, based on estimates of and
judgments related to the weighted average costs of capital of CogenAmerica, and
terminal multiples of estimated EBITDA for CogenAmerica's fiscal year ending
December 31, 2009 ranging from 9.0x to 12.0x. Based on this analysis, DLJ
estimated a value per share of CogenAmerica common stock ranging from $9.62 to
$22.39.

The summary set forth above does not purport to be a complete description
of the analyses performed by DLJ but describes, in summary form, the material
elements of the presentation made by DLJ to the Independent Directors Committee
on August 26, 1999. The preparation of a fairness opinion involves various
determinations as to the most appropriate and relevant methods of financial
analysis and the application of these methods to the particular circumstances
and, therefore, such an opinion is not readily susceptible to partial analysis
or summary description. Each of the analyses conducted by DLJ was carried out in
order to provide a different perspective on the transaction and to add to the
total mix of information available. DLJ did not form a conclusion as to whether
any individual analysis, considered in isolation, supported or failed to support
an opinion as to fairness from a financial point of view. Rather, in reaching
its conclusion, DLJ considered the results of the analyses in light of each
other and ultimately reached its opinion based on the results of all analyses
taken as a whole. DLJ did not place any particular reliance or weight on any
individual analysis or factor considered by it, but instead concluded that its
analyses, taken as a whole, supported its determination. Accordingly,
notwithstanding the separate factors summarized above, DLJ has indicated to
CogenAmerica that it believes that its analyses must be considered as a whole
and that selecting portions of its analyses and the factors considered by it,
without considering all analyses and factors, could create an incomplete view of
the evaluation process underlying its opinion. The analyses performed by DLJ are
not necessarily indicative of actual values or future results, which may be
significantly more or less favorable than suggested by such analyses. Such
analyses were prepared solely as part of DLJ's analysis of the fairness of the
merger price, pursuant to the merger agreement, from a financial point of view
to the holders of shares of CogenAmerica common stock, other than NRG, and were
provided to the CogenAmerica Board of Directors in connection with the delivery
of DLJ's written opinion, dated August 26, 1999. The analyses do not purport to
be appraisals or to reflect the prices at which CogenAmerica might actually be
sold. In addition, as described above, DLJ's

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opinion and presentation to the CogenAmerica Board of Directors is one of many
factors taken into consideration by the CogenAmerica Board of Directors in
making its determination to approve the merger. Consequently, the DLJ analysis
described above should not be viewed as determinative of the opinion of the
CogenAmerica Board of Directors or the view of the management of CogenAmerica
with respect to the value of CogenAmerica.

Other Relationships. In the ordinary course of business, DLJ and its
affiliates may own or actively trade the securities of CogenAmerica, Calpine and
NSP for their own accounts and for the accounts of their customers and,
accordingly, may at any time hold a long or short position in CogenAmerica, NSP
or Calpine securities. In addition, DLJ, as part of its investment banking
services, is regularly engaged in the valuation of businesses and securities in
connection with mergers, acquisitions, underwritings, sales and distributions of
listed and unlisted securities, private placements and valuations for estate,
corporate and other purposes. DLJ has performed investment banking services for
CogenAmerica and Calpine in the past and has been compensated for such services.
DLJ acted as co-lead manager for Calpine's secondary offering of 7,200,000
common shares which closed in November 1999.

Engagement Letter. Pursuant to the terms of a letter agreement, dated June
3, 1999, between CogenAmerica and DLJ, CogenAmerica (1) has agreed to pay DLJ
(a) a retainer fee of $200,000 and (b) a fee of $750,000 upon notification by
DLJ that it is prepared to deliver a fairness opinion with respect to a
transaction covered under the letter agreement, and (2) a transaction fee equal
to $2,500,000; plus, if the price per share of the outstanding CogenAmerica
common stock in any transaction exceeds $21.00, three percent (3%) of the amount
by which such price per share exceeds $21.00 multiplied by the number of shares
of CogenAmerica common stock outstanding (treating any shares issuable upon
exercise of options, warrants or other rights of conversion as outstanding) upon
consummation of the merger. The fees paid to DLJ pursuant to clause (1) of the
first sentence of this paragraph are to be deducted from the transaction fee to
which DLJ is entitled upon consummation of the merger. In addition, CogenAmerica
has agreed to reimburse DLJ, upon request by DLJ from time to time, for all
out-of-pocket expenses (including the reasonable fees and expenses of counsel)
incurred by DLJ in connection with its engagement and to indemnify DLJ and
certain related persons against certain liabilities and expenses in connection
with its engagement, including liabilities under federal securities laws. DLJ
and CogenAmerica negotiated the terms of the fee arrangement. DLJ has consented
to this summary of this opinion and the attachment of this opinion as an
appendix to this proxy statement.

PERSPECTIVE OF NRG ON THE FAIRNESS OF THE MERGER

NRG has concluded that the merger and related transactions are fair to
CogenAmerica and the unaffiliated CogenAmerica stockholders. In addition, the
Independent Directors Committee and DLJ made a determination as to the
substantive fairness of the transaction. See "Special Factors - Recommendations
of the Independent Directors Committee and the Board of Directors" and
"-- Opinion of Financial Advisor." NRG's conclusion is based upon the following
reasons:

1. The Independent Directors Committee consisted only of board members
representing solely the interests of CogenAmerica and the stockholders
other than NRG.

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2. The Independent Directors Committee was advised by independent
legal counsel retained to negotiate on behalf of CogenAmerica and the
stockholders other than NRG.

3. The Independent Directors Committee retained, and received advice
from, DLJ as its independent financial advisor to assist in the conduct of
a sale process and assist in the evaluation of the proposed transaction.

4. The $25.00 per share price and the other terms and conditions of
the merger agreement resulted from an extensive sale process and
arms'-length bargaining between representatives of the Independent
Directors Committee and Calpine and their respective advisors.

5. The conclusions and recommendations of the Independent Directors
Committee and the Board of Directors (see "Special Factors -
Recommendations of the Independent Directors Committee and the Board of
Directors" and "-- Opinion of Financial Advisor.")

The affirmative vote of more than 66 2/3% of the outstanding shares of
CogenAmerica common stock is required to approve and adopt the merger agreement
and related transactions. NRG currently holds 45.3% of the outstanding shares of
CogenAmerica common stock and has granted a proxy to Calpine to vote the
CogenAmerica shares owned by NRG for adoption and approval of the merger
agreement and charter amendment. See "Summary-Record Date; Voting Power; Votes
Required." The transaction is not structured to require the affirmative vote of
a majority of unaffiliated stockholders to approve the merger. Nevertheless,
approval of the merger requires the affirmative vote of a significant amount of
unaffiliated stockholders. In addition, the Independent Directors Committee did
not perceive the lack of a vote of the majority of unaffiliated stockholders as
an important factor in its consideration of the merger agreement and related
transactions on behalf of the Company and its unaffiliated stockholders. See
"Reasons for the Merger -- Stockholder Vote." In light of the foregoing, NRG
believes that the merger agreement and related transactions are procedurally
fair despite the absence of a requirement that the majority of unaffiliated
CogenAmerica stockholders approve the transaction.

PLANS FOR COGENAMERICA AFTER THE MERGER

CogenAmerica has been advised by Calpine that it intends to conduct a
review of CogenAmerica and its assets, corporate structure, dividend policy,
capitalization, operations, properties and policies and to consider, subject to
the terms of the merger agreement, what, if any, changes would be desirable in
light of the circumstances then existing, and reserves the right to take such
actions or effect such changes as it deems desirable. Such changes could include
changes in CogenAmerica's business, operations, corporate structure,
capitalization, Board of Directors, or policies.

Upon consummation of the merger, Calpine will own 80% of the fully-diluted
equity and voting power of CogenAmerica. The merger agreement provides that the
directors and officers of Acquisition Sub will be the directors and officers of
CogenAmerica after the completion of the merger. The Calpine/NRG Agreement
provides that the board of directors of the surviving corporation will consist
of no more than seven directors, one of which shall be appointed by NRG.

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Except as described in this proxy statement, CogenAmerica and its
affiliates currently have no plans or proposals which relate to or would result
in an extraordinary corporate transaction involving CogenAmerica or any of its
subsidiaries, such as a merger, reorganization, liquidation, relocation of any
operations or sale or other transfer of a material amount of assets, any change
in the CogenAmerica Board of Directors or management (other than as described
above), any material change in CogenAmerica's capitalization or dividend policy
or any other material change in CogenAmerica's corporate structure or business,
CogenAmerica Board of Directors or management.

CERTAIN EFFECTS OF THE MERGER

As a result of the merger, the equity interests of CogenAmerica will be
owned 80% by Calpine and 20% by NRG, and the current stockholders, other than
NRG, will have no continuing interest in CogenAmerica. Therefore, following the
merger, the stockholders of CogenAmerica, other than NRG, will no longer benefit
from any increases in the value of CogenAmerica and will no longer bear the risk
of any decreases in the value of CogenAmerica. Following the merger, the
operation of CogenAmerica will be subject, among other things, to the agreements
between Calpine and NRG reflected in the Calpine/NRG Agreement. For a
description of the Calpine/NRG Agreement, see the section under the caption
"Summary of Calpine/NRG Agreement" below.

Following the merger, the CogenAmerica common stock will no longer meet the
requirements of The Nasdaq National Market for continued listing and therefore
will be delisted from The Nasdaq National Market.

CogenAmerica common stock is currently registered as a class of securities
under the Securities Exchange Act of 1934, as amended (the "Exchange Act").
Registration of the CogenAmerica common stock under the Exchange Act may be
terminated upon application of CogenAmerica to the SEC if the CogenAmerica
common stock is not listed on a national securities exchange or quoted on the
Nasdaq National Market and there are fewer than 300 record holders of the
CogenAmerica common stock. Termination of registration of the CogenAmerica
common stock under the Exchange Act would substantially reduce the information
required to be furnished by CogenAmerica to its stockholders and to the SEC and
would make certain provisions of the Exchange Act, such as the short-swing
trading provisions of Section 16(b), the requirement of furnishing a proxy
statement in connection with the stockholders' meetings pursuant to Section
14(a), and the requirements of Rule 13e-3 under the Exchange Act with respect to
"going private" transactions, no longer applicable to CogenAmerica. It is the
present intention of Calpine and NRG to cause CogenAmerica to make an
application for the termination of the registration of the CogenAmerica common
stock under the Exchange Act as soon as practicable after completion of the
merger.

UNSOLICITED OFFERS FROM THIRD PARTIES

Since entering into the merger agreement on August 26, 1999 to the date of
this proxy statement, CogenAmerica has not received any unsolicited offers from
third parties for a merger or other business combination involving CogenAmerica
or any of its subsidiaries or any unsolicited proposal or offer to acquire in
any manner a substantial equity interest in, a substantial portion of the voting
securities of, or a substantial portion of the assets of CogenAmerica or any of
its subsidiaries, other than the transactions contemplated by the merger
agreement.

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CONFLICTS OF INTEREST

In considering the actions of the Independent Directors Committee and the
Board of Directors of CogenAmerica with respect to the merger, stockholders
should be aware that directors and officers of CogenAmerica, as well as NRG,
have interests in connection with the merger which may present them with actual
or potential conflicts of interest as summarized below. The CogenAmerica Board
of Directors was aware of these interests and considered them among the other
matters described, but such conflicts,
individually or in the aggregate, did not influence the determination of the
Independent Directors Committee or the Board of Directors of CogenAmerica that
the merger is fair to and in the best interests of the CogenAmerica stockholders
(other than NRG).

Arrangements with NRG. As of the close of business on August 26, 1999, the
date on which the merger agreement was signed, NRG beneficially owned 3,106,612
shares of CogenAmerica common stock, or approximately 45.3% of the outstanding
shares of CogenAmerica common stock. NRG and its subsidiaries also have various
agreements with CogenAmerica and its subsidiaries that affect the operation and
conduct of CogenAmerica's business. The agreements consist of the following: (1)
a co-investment agreement pursuant to which NRG agreed to offer to sell
CogenAmerica certain independent power plants which is how CogenAmerica acquired
the power plants it currently owns in Pryor, Oklahoma and Morris, Illinois; (2)
a management services agreement pursuant to which NRG provides certain
management and technical services to CogenAmerica and its subsidiaries and is
reimbursed for its costs and expenses for providing the services; (3) separate
operation and maintenance agreements (each an "O&M Agreement") for
CogenAmerica's plants in Newark and Parlin, New Jersey and Morris, Illinois
pursuant to which NRG operates those plants in return for a fixed annual fee
subject to certain offsets plus reimbursement of all costs and expenses incurred
to operate the plants; (4) loan and security agreements pursuant to which NRG
made certain loans to CogenAmerica or its subsidiaries and was granted certain
security interests in the assets of CogenAmerica or its subsidiaries; and (5)
various agreements pursuant to which either NRG or CogenAmerica sold the other
certain assets or stock of certain corporations. Pursuant to the co-investment
agreement, NRG sold CogenAmerica the plant in Pryor, Oklahoma for $23.9 million
in 1998 and the plant in Morris, Illinois for a development fee of $4.8 million
paid to NRG plus assumption of liabilities related to the project. For the year
ended December 31, 1998 and the six months ended June 30, 1999, NRG has charged
CogenAmerica $422,227 and $52,527, respectively, under the management services
agreement. For the year ended December 31, 1998 and the six months ended June
30, 1999, NRG has charged CogenAmerica management fees of $147,033 and $73,641,
respectively, and operating cost reimbursements of $35,657 and $17,904,
respectively, under the O&M Agreement for the Newark, New Jersey plant. For the
year ended December 31, 1998 and the six months ended June 30, 1999, NRG has
charged CogenAmerica management fees of $196,044 and $98,189, respectively, and
operating cost reimbursements of $59,705 and $24,180, respectively, under the
O&M Agreement for the Parlin, New Jersey plant. For the year ended December 31,
1998 and the six months ended June 30, 1999, NRG has charged CogenAmerica
management fees of none and $166,667, respectively, and operating cost
reimbursements of none and $35,883, respectively, under the O&M Agreement for
the Morris, Illinois plant. As of August 31, 1999, CogenAmerica owed NRG for
borrowed money an aggregate of $55,191,100 consisting of $53,933,649 in
principal and $1,257,451 in accrued interest. In connection with completion of
the merger, the various Affiliate Agreements will be terminated pursuant to the

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Termination Agreement and the NRG and CogenAmerica parties will exchange mutual
general releases subject to certain exceptions.

Arrangements between Calpine and NRG. In addition to the Calpine/NRG
Agreement, Calpine and NRG entered into an acknowledgement pursuant to which NRG
consented to the execution of certain agreements by CogenAmerica at the
effective time of the merger with Calpine including (i) a tax sharing agreement,
(ii) a management services agreement, (iii) operating and maintenance agreements
for certain of CogenAmerica's project subsidiaries and (iv) a form of energy
services agreement which may be entered into with certain of CogenAmerica's
project subsidiaries.

The tax sharing agreement, which will be entered into at the effective time
of the merger, allocates responsibility between Calpine and CogenAmerica for
preparing and filing tax returns and specifies which party will make tax
payments and how tax liabilities and obligations will be allocated among the
parties.

The form of energy services agreement, if entered into between Calpine and
a CogenAmerica project subsidiary, provides that Calpine will provide fuel
management, marketing and contract administration services in connection with
such subsidiary's gas agreements and will perform certain other services related
to the project. The agreement also provides that Calpine will provide marketing,
scheduling and contract administration services with respect to power generated
by each such project. Under the agreement, in exchange for such services,
CogenAmerica will pay Calpine $10,000 per month in the aggregate for all project
subsidiaries which execute energy services agreements.

The management services agreement, if entered into at the effective time of
the merger, will be on substantially the same terms as CogenAmerica's existing
management services agreement with NRG. The management services agreement
provides that Calpine will provide management, administrative, operation,
maintenance and certain other services to CogenAmerica in connection with
CogenAmerica's day to day business.

The operating and maintenance agreement for the Morris, Illinois, Newark,
New Jersey and Parlin, New Jersey projects, if entered into at the effective
time of the merger, will be on substantially the same terms as CogenAmerica's
existing operating and maintenance agreements with NRG for such projects. The
operating and maintenance agreement for the Pryor, Oklahoma project, if entered
into at the effective time of the merger, will be in a form previously agreed to
by Calpine and NRG.

Directors and Officers of CogenAmerica. Four members of the CogenAmerica
Board of Directors were officers of NRG as of the date the CogenAmerica Board of
Directors approved the merger agreement. David H. Peterson, a director and
Chairman of CogenAmerica, is Chairman of the Board, President and Chief
Executive Officer of NRG. Craig A. Mataczynski, a director of CogenAmerica, is
the President and Chief Executive Officer of NRG's North America Division.
Ronald J. Will, a director of CogenAmerica, is the Managing Director and Chief
Executive Officer of NRG's European operations. Michael O'Sullivan, a director
of CogenAmerica, was a Vice President of NRG's North America Division until he
resigned effective September 3, 1999 to accept a position with a party not
affiliated with NRG. Messrs. Peterson, Mataczynski and Will each hold options to
acquire 30,000 shares of CogenAmerica common stock at an exercise price of
$5.4375 per share. NRG has advised CogenAmerica that current NRG corporate
policy prohibits NRG employees, including Messrs. Peterson, Mataczynski and
Will, from receiving the economic benefit of the options granted to them in
their capacities as directors of

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CogenAmerica. The NRG employees who serve as directors of CogenAmerica and were
previously granted stock options in their capacity as directors of CogenAmerica,
have agreed to the cancellation of their stock options. The amount of NRG's
required contribution into Acquisition Sub will be reduced by the amount
determined by multiplying (i) the number of cancelled options by (ii) the excess
of $25.00 over the exercise prices for the options, thereby ensuring that NRG
receives credit equal to the value of the cancelled options by the Board members
who are employees of NRG. The NRG employees who serve as directors of
CogenAmerica and whose options have been cancelled will receive no cash payment
for these options. Julie A. Jorgensen, a director and the President and Chief
Executive Officer of CogenAmerica, owns 1,500 shares of CogenAmerica common
stock and has options to purchase 30,000 shares of CogenAmerica common stock at
$9.125 per share and 200,000 shares of CogenAmerica common stock at $11.5625 per
share, including 100,000 shares which will become vested and exercisable as a
result of the completion of the merger. The three disinterested directors who
comprise the Independent Directors Committee are Mark Liddell, Lawrence I.
Littman and Charles T. Thayer. CogenAmerica has a policy of granting options to
non-employee directors. Mr. Liddell who was elected as a director at the 1999
annual meeting has an option to acquire 10,000 shares of CogenAmerica common
stock at $12.375 per share which will become vested and exercisable upon
completion of the merger. Mr. Littman owns 70 shares of CogenAmerica common
stock and has options to acquire 30,000 shares at an exercise price of $5.4375
per share. Mr. Thayer owns 40,000 shares of CogenAmerica common stock and has
options to acquire 10,000 shares at an exercise price of $5.4375 per share. A
description of the value of options for each executive officer is included under
"Interests in Securities of CogenAmerica" (page 53).

Severance Agreements for Officers. Under the employment agreement dated May
1, 1999 between CogenAmerica and Ms. Jorgensen, Ms. Jorgensen will be entitled
to terminate her employment after completion of the merger and receive a lump
sum severance payment equal to her base annual salary ($200,000) plus her
current annual target bonus ($100,000) for a total payment of $300,000. On June
11, 1999, the Compensation Committee of the CogenAmerica Board of Directors
adopted a severance policy for designated employees, including officers other
than Ms. Jorgensen, that provides the following severance in the event of a
termination of employment for any reason after the merger: (1) the payment in a
lump sum of the balance of the employee's 1999 base salary and target bonus or
maximum bonus depending upon the timing of the payment elected by the employee;
(2) the payment in a lump sum of the employee's base salary for a specified
period that is 12 months for officers of CogenAmerica, and (3) continuation of
health, dental, life and disability insurance benefits for the severance period.
Assuming that the merger and termination of employment occurs on December 15,
1999, officers of CogenAmerica other than Ms. Jorgensen would receive the
following payments for salary and bonus: $278,092 (target bonus) or $459,292
(maximum bonus) to Timothy P. Hunstad, Vice President and Chief Financial
Officer; $307,558 (target bonus) or $507,958 (maximum bonus) to Richard C.
Stone, Vice President -- Business Development and Marketing; and $208,125
(target bonus) or $329,625 (maximum bonus) to Thomas L. Osteraas, General
Counsel and Secretary.

Indemnification. The bylaws of CogenAmerica provide for the indemnification
of its directors and officers against expenses and liabilities in connection
with any proceeding by reason of his or her being or having been a director or
officer. The merger agreement provides that for six years after the merger,
Calpine will cause CogenAmerica to indemnify all past and present officers and
directors of CogenAmerica and its subsidiaries to the same

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extent as is indemnified at the date of the merger agreement for acts or
omissions occurring at or prior to the merger. Calpine also agreed to provide,
or cause CogenAmerica as the surviving corporation in the merger, for not less
than six years after the merger, a directors' and officers' insurance and
indemnification policy providing coverage for events occurring prior to the
merger with coverage substantially similar to CogenAmerica's existing policy or,
if substantially similar coverage is unavailable, then best available coverage.
Calpine and CogenAmerica are not collectively required to pay premiums of more
than $360,000 in any calendar year.

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SUMMARY OF MATERIAL FEATURES OF THE MERGER

THE MERGER

General. The merger agreement provides that, subject to its conditions and
in accordance with the DGCL, Acquisition Sub will be merged into CogenAmerica
when a certificate of merger is filed with the Delaware Secretary of State or
such other date or time as is stated in the certificate of merger. Following the
merger, the separate existence of Acquisition Sub will cease, and CogenAmerica
will continue as the surviving corporation. At the effective time, each issued
and outstanding share of CogenAmerica common stock, other than shares owned by
CogenAmerica, by Acquisition Sub or by stockholders who exercise their appraisal
rights, will be converted into the right to receive, upon surrender of the
certificate formerly representing the shares of CogenAmerica common stock (the
"Certificate"), $25.00 in cash. As a result of the merger, the CogenAmerica
common stock will no longer be publicly traded and the equity of the surviving
corporation will be owned 80% by Calpine and 20% by NRG.

Merger Consideration. When the merger is completed, each share of
CogenAmerica common stock issued and outstanding immediately prior to the
effective time of the merger will no longer be outstanding and will
automatically be canceled and retired. Each holder of a Certificate will have
only the right to receive an amount in cash equal to the number of such shares
multiplied by $25.00 per share at the time the Certificate is surrendered.

Payment for Shares. As soon as practicable, after the effective time,
America Stock Transfer Company (the "Payment Agent") will mail to each holder of
record of a Certificate a form of letter of transmittal which instructs
CogenAmerica stockholders how to surrender their shares of CogenAmerica common
stock and receive the merger consideration. Risk of loss and title to the
Certificate will pass only when the Payment Agent receives delivery. When a
record holder has delivered to the Payment Agent all Certificates for its shares
of CogenAmerica common stock together with the duly executed letter of
transmittal, the Payment Agent will issue a check for the merger consideration,
net of any withholding or other taxes, if applicable, and mail the check to the
record holder.

Stock Options and Warrant. The merger agreement provides that at the
effective time of the merger all options and the warrant to purchase
CogenAmerica common stock will be canceled and each holder of an option or
warrant will have the right to receive, upon execution and delivery to the
Payment Agent of an option or warrant termination agreement, with respect to his
or her options, a cash payment equal to (a) the excess, if any, of $25.00 over
the exercise price of his or her option or warrant, multiplied by (b) the total
number of shares of CogenAmerica common stock for which such option or warrant
are then vested and exercisable (after giving effect to any acceleration of
vesting as a result of the consummation of the merger) pursuant to the terms of
such option or warrant. The payment of the consideration for an option, net of
any withholding or other applicable taxes, or for the warrant upon delivery to
the Payment Agent of an option or warrant termination agreement, will constitute
full satisfaction of all rights pertaining to the option or for the warrant.

Closing of Transfer Books. At the effective time of the merger, the stock
transfer books of CogenAmerica will be closed and no further transfer of shares
of CogenAmerica common stock will be made on the records of CogenAmerica. On or
after the effective

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time, any Certificates presented to the surviving corporation or the Payment
Agent will be canceled and exchanged for the merger consideration.

CONDITIONS TO THE MERGER.

Each party's obligation to complete the merger is conditioned upon the
following: (a) adoption and approval of the merger agreement by the vote of the
holders of more than 66 2/3% of the outstanding shares of the CogenAmerica
common stock, (b) approval of the charter amendment by the vote of the holders
of more than 50% of the outstanding shares of CogenAmerica common stock, (c)
expiration or termination of the waiting period (and any extension thereof)
applicable to the merger under the HSR Act, (d) the obtaining of all
authorizations, consents, orders, declarations or approvals of, or filings with,
or terminations or expirations of waiting periods imposed by, any governmental
entity, the failure of which would have the effect of making the merger or any
transaction described in the merger agreement illegal or would have,
individually or in the aggregate, a material adverse effect on Calpine (assuming
the merger has taken place), and (e) the absence of any statute, rule,
regulation, legislation, interpretation, judgment, order or injunction or other
action (i) challenging the acquisition by Calpine or Acquisition Sub of any
CogenAmerica common stock, (ii) seeking to prohibit or limit the ownership or
operation by CogenAmerica, Calpine or any of their respective subsidiaries of
any material portion of the business or assets of CogenAmerica, Calpine or any
of their respective subsidiaries, or to compel CogenAmerica, Calpine or any of
their respective subsidiaries to dispose of or hold separate any material
portion of the business or assets of CogenAmerica, Calpine or any of their
respective subsidiaries, (iii) seeking to impose limitations on the ability of
Calpine or Acquisition Sub to acquire or hold, or exercise full rights of
ownership of, any shares of CogenAmerica common stock, including the right to
vote the CogenAmerica common stock purchased by it on all matters properly
presented to the stockholders of CogenAmerica, (iv) seeking to prohibit Calpine
or any of its subsidiaries from effectively controlling in any material respect
the business or operations of CogenAmerica and its subsidiaries in connection
with the merger or the merger agreement, or (v) which otherwise is reasonably
likely to have a material adverse effect on CogenAmerica.

The obligation of CogenAmerica to complete the merger is subject to the
satisfaction of the following conditions at or prior to the effective time: (a)
each of Calpine and Acquisition Sub has performed in all material respects each
of its agreements contained in the merger agreement and the representations and
warranties of Calpine and Acquisition Sub contained in the merger agreement are
true and complete except for such exceptions as would not have a material
adverse effect on Calpine; and (b) no governmental entity has imposed any
requirement which, individually or in the aggregate, would have a material
adverse effect on Calpine.

The obligations of Calpine and Acquisition Sub to complete the merger are
subject to the satisfaction of the following conditions at or prior to the
effective time: (a) CogenAmerica shall have complied with covenants regarding
conduct of CogenAmerica's business in the merger agreement and complies with its
agreements and covenants contained in the merger agreement in all material
respects and the representations and warranties of CogenAmerica contained in the
merger agreement shall be true and complete except for such exceptions as would
not have a material adverse effect on CogenAmerica; (b) there shall not be
instituted or pending any suit, action or proceeding initiated as a result of
the merger agreement or any transactions contemplated thereby (i) challenging
the acquisition by Calpine or Acquisition Sub of any CogenAmerica common

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stock, seeking to restrain or prohibit the making or consummation of the merger
or any other transaction, (ii) seeking to prohibit or limit the ownership or
operation by CogenAmerica, Calpine or any of their respective subsidiaries of
any material portion of the business or assets of CogenAmerica, Calpine or any
of their respective subsidiaries, or to compel CogenAmerica, Calpine or any of
their respective subsidiaries to dispose of or hold separate any material
portion of the business or assets of CogenAmerica, Calpine or any of their
respective subsidiaries, (iii) seeking to impose limitations on the ability of
Calpine or Acquisition Sub to acquire or hold, or exercise full rights of
ownership of, any shares of CogenAmerica common stock, including the right to
vote CogenAmerica common stock purchased by it on all matters properly presented
to the CogenAmerica stockholders, (iv) seeking to prohibit Calpine or any of its
subsidiaries from effectively controlling in any material respect the business
or operations of CogenAmerica and its subsidiaries in connection with the merger
or the merger agreement, or (v) which otherwise is reasonably likely to have a
material adverse effect on CogenAmerica; and (c) since the date of the merger
agreement, there shall not have occurred any event, change, effect or
development that, individually or in the aggregate, has had or would be
reasonably expected to have a material adverse effect on CogenAmerica.

EVEN IF THE COGENAMERICA STOCKHOLDERS APPROVE AND ADOPT THE MERGER
AGREEMENT, THERE CAN BE NO ASSURANCE THAT THE MERGER WILL BE COMPLETED.

REPRESENTATIONS AND WARRANTIES.

CogenAmerica made representations and warranties in the merger agreement,
qualified in certain instances by materiality or as disclosed in CogenAmerica's
disclosure letter (the "CogenAmerica Letter") regarding the following: its
organization and good standing; authority to enter into the merger agreement and
complete the transactions contemplated by the merger agreement; the capital
structure of CogenAmerica and its subsidiaries; the non-contravention of the
merger agreement with CogenAmerica's certificate of incorporation, bylaws, any
contract or law; requisite governmental and other consents and approvals;
compliance with the SEC filing requirements; its financial statements; the
accuracy of information in this proxy statement and compliance with the Exchange
Act; the absence of certain material changes since December 31, 1998; possession
of permits and compliance with governing documents and laws; absence of
undisclosed material contracts; absence of material events of default or basis
for material events of default; requisite tax filings and examinations; absence
of outstanding orders, judgments, injunctions and similar actions and absence of
disputes involving CogenAmerica or its subsidiaries or their businesses;
agreements relating to certain employment, consulting and benefit matters of
CogenAmerica; compliance with worker safety, labor and employment and
environmental laws; absence of state takeover laws applicable to CogenAmerica;
the required vote of stockholders of CogenAmerica necessary to approve the
merger agreement; absence of brokers or similar fees other than to DLJ; the
receipt of the DLJ fairness opinion; the applicability and compliance with
certain utility regulations; insurance coverage; and related party transactions.

CERTAIN COVENANTS.

Until the merger is completed, CogenAmerica has agreed that CogenAmerica
and its subsidiaries will conduct their business in the ordinary course and use
their best efforts to preserve their current business organizations, keep
available the services of its current officers and employees and preserve their
third party relationships.

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CogenAmerica has also agreed that, without the consent of Calpine unless
contemplated by the CogenAmerica disclosure, neither CogenAmerica nor its
subsidiaries will: (a) declare or pay any dividend on or make any other
distribution in respect of its capital stock, or split, combine or reclassify
any class of stock or purchase, redeem or acquire any shares of capital stock;
(b) issue or encumber any shares of its capital stock or other securities other
than the issuance of shares of CogenAmerica common stock upon the exercise of
options; (c) amend its governing documents; (d) acquire by merger or
consolidation or asset purchase or equity purchase any entity or division other
than transactions in the ordinary course of business consistent with past
practice and that have a transaction value of less than $250,000 individually or
$1,000,000 in the aggregate and which are not material to CogenAmerica; (e) sell
or otherwise dispose of assets other than in the ordinary course of business
consistent with past practice and that have a transaction value of less than
$250,000 individually or $1,000,000 in the aggregate; (f) incur indebtedness for
borrowed money or make loans or investments, except for obligations incurred in
the ordinary course of business consistent with past practice that are less than
$500,000 in the aggregate and transactions between or among CogenAmerica and its
subsidiaries; (g) alter the corporate structure or ownership of CogenAmerica or
its subsidiaries; (h) adopt or amend existing benefit plans, severance plans or
employment or consulting agreements, except for immaterial changes as required
by applicable law; (i) increase compensation to directors, officers, employees,
independent contractors or consultants, grant severance or termination pay or
enhance or accelerate rights under any plan or arrangement for the benefit of
any director, officer, employee, independent contractor or consultant; (j)
violate or fail to perform any obligation imposed by material federal, state or
local law, rule or regulation; (k) change any accounting policies or procedures,
except as required to by generally accepted accounting principles; (l) file tax
returns inconsistent with past practice or take any position inconsistent with
prior positions; (m) make tax elections or settle or compromise any material tax
liability; (n) enter into or amend any contract which involves aggregate
payments in excess of $250,000 for individual contracts or $1,000,000 in the
aggregate for all contracts or make or agree to make new capital expenditures in
excess of $250,000 individually or $500,000 in the aggregate; or (o) pay or
discharge any obligations other than the payment or discharge of obligations in
the ordinary course of business consistent with past practice that are reflected
in or as contemplated by the most recent financial statements, or certain
payments of indebtedness owed by CogenAmerica or a subsidiary under an existing
credit facility.

NO SOLICITATION OF TRANSACTIONS.

The merger agreement provides that CogenAmerica will not, directly or
indirectly (a) solicit, initiate or encourage the submission of any Takeover
Proposal (as defined below), (b) enter into any agreement with respect to any
Takeover Proposal, or (c) participate in any discussions or negotiations
regarding, or furnish to any person any information with respect to, or take any
other action to facilitate any inquiries or the making of any proposal that
constitutes, or may reasonably be expected to lead to, any Takeover Proposal. If
the CogenAmerica Board of Directors reasonably determines the Takeover Proposal
constitutes a Superior Proposal (as defined below), then, to the extent required
by the fiduciary obligations of the CogenAmerica Board of Directors, as
determined in good faith by a majority of the disinterested members after
receiving the advice of independent legal counsel, CogenAmerica may, in response
to an unsolicited request, furnish information with respect to CogenAmerica to,
and enter into discussions

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with, any person that has made such a Takeover Proposal pursuant to a customary
confidentiality agreement.

The merger agreement defines a "Takeover Proposal" to mean any proposal for
a merger or other business combination involving CogenAmerica or any of its
subsidiaries or any proposal or offer to acquire in any manner, directly or
indirectly, a substantial equity interest in, a substantial portion of the
voting securities of, or a substantial portion of the assets of CogenAmerica or
any of its subsidiaries, other than the transactions contemplated by the merger
agreement. A "Superior Proposal" means a bona fide Takeover Proposal made by a
third party which a majority of the disinterested members of the CogenAmerica
Board of Directors determines in its reasonable good faith judgment to be more
favorable to CogenAmerica's stockholders than the merger, and for which
financing, to the extent required, is then committed or which, in the reasonable
good faith judgment of a majority of such disinterested members is highly likely
to be financed by the third party. In making these determinations and judgments,
the CogenAmerica Board of Directors must receive a written opinion from an
independent financial advisor of nationally recognized reputation that the value
of the consideration provided for in the alternative proposal exceeds the value
of the consideration provided for in the merger and written advice as to the
likelihood of the third party obtaining any necessary financing.

The merger agreement requires CogenAmerica to advise Calpine of (a) any
Takeover Proposal or inquiry with respect to or which could lead to any Takeover
Proposal, (b) the material terms of such Takeover Proposal, and (c) the identity
of the person making any such Takeover Proposal or inquiry. The merger agreement
also requires CogenAmerica to keep Calpine fully informed of the status and
details of any such Takeover Proposal or inquiry.

TERMINATION.

The merger agreement may be terminated at any time prior to the effective
time, whether before or after approval of the matters presented in connection
with the merger by the stockholders of CogenAmerica:

1. by mutual written consent of Calpine and CogenAmerica; or

2. by either Calpine or CogenAmerica if the other party fails to
comply in any material respect with any of its covenants or agreements in
the merger agreement, and the failure is not cured within 30 business days
following receipt of notice; or

3. by either Calpine or CogenAmerica if there has been a breach by the
other party (in the case of Calpine including a material breach by
Acquisition Sub) of any representation or warranty that would have a
material adverse effect on the breaching party or would prevent the
breaching party from consummating the merger; or

4. by either Calpine or CogenAmerica if the merger has not been
effected on or prior to the later of (a) February 28, 2000 or, if the sole
reason that the merger has not been consummated by February 28, 2000 is
that the special meeting has not been held by such date, or (b) March 31,
2000, in either case for a reason other than the failure of the terminating
party to comply with its obligations under the merger agreement; or

5. by either Calpine or CogenAmerica if any court or other
governmental entity having jurisdiction has issued an order or taken other
action permanently enjoining or

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otherwise prohibiting the transactions contemplated by the merger agreement
and such action has become final and nonappealable; or

6. by either Calpine or CogenAmerica if the stockholders of
CogenAmerica do not approve the merger agreement at the special meeting or
any adjournment or postponement thereof; or

7. by CogenAmerica if concurrently with or immediately after such
termination, CogenAmerica enters into a merger, acquisition or other
agreement to affect a Superior Proposal and prior to such termination
CogenAmerica has (a) delivered to Calpine a written notice of intent to
enter into an agreement to effect a Superior Proposal, (b) four business
days have elapsed following the notice, (c) CogenAmerica informed Calpine
of the terms and conditions of the Takeover Proposal and the identity of
the person making the proposal, (d) the CogenAmerica Board of Directors has
continued reasonably to believe following the notice period that the
Takeover Proposal constitutes a Superior Proposal after taking into account
any amendment of the terms of the merger by Calpine or any proposal by
Calpine to amend the terms of the merger agreement, the merger or any other
Takeover Proposal made by Calpine, and (e) CogenAmerica has paid Calpine a
termination fee of $7,500,000; or

8. by Calpine if prior to the effective time the CogenAmerica Board of
Directors or any committee thereof shall have withdrawn or modified in a
manner adverse to Calpine or Acquisition Sub its approval or recommendation
of the merger or shall have recommended or approved a Superior Proposal, or
shall have resolved to do any of the foregoing.

TERMINATION FEE.

If (a) the merger agreement is terminated pursuant to paragraph 7 of the
preceding section entitled "-- Termination" or (b) if (i) the merger agreement
is terminated by (A) CogenAmerica or Calpine pursuant to paragraph 6 of the
preceding section or (B) by Calpine pursuant to paragraphs 2, 3 or 8 of the
preceding section, (ii) prior to such termination any person makes a Takeover
Proposal, and (iii) concurrently with or within 12 months after such a
termination a Third Party Acquisition Event (as defined below) occurs, in each
case CogenAmerica will be obligated to pay to Calpine a termination fee of
$7,500,000 in cash (the "Termination Fee").

A "Third Party Acquisition Event" occurs when, pursuant to a legally
binding definitive agreement or agreement in principal with CogenAmerica, any
person, entity or group (other than Calpine, Acquisition Sub or any of their
affiliates), in one or a series of transactions, acquires more than 50% of the
outstanding CogenAmerica common stock or assets of CogenAmerica through open
market purchases, merger, consolidation, tender or exchange offer,
reorganization or other business combination.

INDEMNIFICATION.

The merger agreement provides that for six years from the effective time,
Calpine will cause the surviving corporation to indemnify and hold harmless all
past and present officers and directors of CogenAmerica to the same extent as
such persons are indemnified at the date of the merger agreement for acts or
omissions occurring at or prior to the effective time. Calpine has agreed to
provide, or cause the surviving corporation to provide, for not less than six
years from the effective time a directors and officers insurance and

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indemnification policy providing coverage for events occurring prior to the
effective time with coverage substantially similar to CogenAmerica's existing
policy or if substantially similar coverage is unavailable, then best available,
provided that Calpine shall not be required to pay premiums aggregating more
than $360,000 in any calendar year.

AMENDMENT AND WAIVER.

The merger agreement may be amended pursuant to action taken or authorized
by the respective Boards of Directors of Calpine and CogenAmerica at any time
prior to or after approval of the merger agreement by the stockholders of
CogenAmerica but, after such approval, no amendment will be made without the
further approval of the stockholders if further approval is required by law. At
any time prior to the effective time, any of the parties to the merger agreement
may extend, in writing, the time for performance of any obligations or other
acts of the other party, waive any inaccuracies in the representations and
warranties contained in the merger agreement or any document delivered pursuant
to the merger agreement and waive compliance with any of the agreements or
conditions contained in the merger agreement.

EXPENSES.

Whether or not the merger is consummated, all costs and expenses incurred
in connection with the merger agreement and the transactions contemplated
thereby will be paid by the party incurring such expense.

EFFECTIVE TIME

The merger will become effective at the effective time. It is expected that
the effective time will be the date of closing of the merger, which is expected
to be December 16, 1999, or as soon thereafter as is practicable subject to
satisfaction or waiver of the conditions to closing.

CONVERSION OF COMMON STOCK

As of the effective time, each share of CogenAmerica common stock issued
and outstanding immediately prior to the effective time of the merger (other
than shares owned by CogenAmerica, by Acquisition Sub or by stockholders who
properly exercise their appraisal rights under the DGCL) will be converted into
the right to receive the merger consideration when the Certificate formerly
representing such share of CogenAmerica common stock is surrendered and a duly
executed letter of transmittal is delivered to the Payment Agent. The Payment
Agent will mail to each record holder of CogenAmerica common stock, as soon as
practicable after the effective time of the merger, a letter of transmittal
which will contain instructions for surrendering the Certificates for
CogenAmerica common stock in exchange for the merger consideration. When so
converted, all such shares of CogenAmerica common stock will no longer be
outstanding and will automatically be canceled and retired and each holder of a
Certificate formerly representing any such shares will have only the right to
receive the merger consideration in cash (without interest) upon the surrender
of the Certificate. Holders of options will receive payment in accordance with
the procedures described below under "Payment for Stock Options."

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As soon as practicable after the effective time of the merger, Calpine will
deposit with the Payment Agent, in trust for the holders of the CogenAmerica
common stock converted in the merger and holders of options, an amount of cash
equal to or exceeding the aggregate merger consideration and the consideration
for the options, net of any withholding or other taxes, if applicable.

COGENAMERICA'S STOCKHOLDERS SHOULD NOT FORWARD THEIR STOCK CERTIFICATES TO
THE PAYMENT AGENT WITHOUT A LETTER OF TRANSMITTAL. STOCK CERTIFICATES SHOULD NOT
BE RETURNED WITH THE ENCLOSED PROXY CARD.

The payment of the merger consideration, net of any withholding or other
taxes, if applicable, upon surrender of any Certificate will be deemed to
constitute full satisfaction of all rights pertaining to the shares of
CogenAmerica common stock represented by the Certificate. Until surrendered as
contemplated by the merger agreement, each Certificate for CogenAmerica common
stock will be deemed at any time after the effective time to represent only the
right to receive the merger consideration upon surrender; no interest will be
paid or will accrue on any merger consideration payable to stockholders. At the
effective time of the merger, the stock transfer books of CogenAmerica will be
closed. Neither Calpine nor the surviving corporation will be liable to any
former stockholder or holder of an option for any cash held in the payment fund
which is delivered to a public official pursuant to any applicable abandoned
property, escheat or similar law.

PAYMENT FOR STOCK OPTIONS AND WARRANT

Each option and the warrant to purchase CogenAmerica common stock which is
outstanding immediately prior to the effective time of the merger will be
canceled, and the holder will have the right to receive, upon execution and
delivery to the Payment Agent of an option or warrant termination agreement, a
cash payment equal to the (a) excess of $25.00 over the exercise price of the
option or warrant, multiplied by (b) the total number of shares of CogenAmerica
common stock for which such option or warrant are then vested and exercisable
(after giving effect to any acceleration of vesting as a result of the
consummation of the merger) pursuant to the terms of such options or warrant.
The payment of the consideration for an option, net of any withholding or other
applicable taxes, or for the warrant upon delivery to the Payment Agent of an
option or warrant termination agreement signed by the holder of the option or
warrant, will constitute full satisfaction of all rights pertaining to the
option or warrant.

CONDUCT OF BUSINESS PENDING THE MERGER

Pursuant to the merger agreement, CogenAmerica has agreed to carry on its
business prior to the effective time of the merger in all material respects in
the ordinary course of its business as conducted on the date of the merger
agreement, subject to certain covenants by CogenAmerica in the merger agreement.

REGULATORY FILINGS AND APPROVALS

CogenAmerica believes that the following filings or approvals are required
with respect to the merger: (a) filings with and approvals of the FERC, (b)
filings by CogenAmerica and Calpine with the Federal Trade Commission and the
Department of Justice pursuant to the requirements of the HSR Act, (c) filings
by CogenAmerica, Calpine, Acquisition

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Sub and NRG with the SEC pursuant to the Exchange Act, (d) filings by
CogenAmerica under the New Jersey Industrial Site Recovery Act, (e) filing the
certificate of amendment to effect the charter amendment with the Delaware
Secretary of State, and (e) filing of the certificate of merger to effect the
merger with the Delaware Secretary of State.

CONDITIONS TO THE MERGER

The obligations of Calpine, Acquisition Sub and CogenAmerica to effect the
merger are subject to the fulfillment of certain conditions described more fully
under "Summary of Material Terms of the Merger Agreement -- Conditions to the
Merger" (page 38).

FEDERAL INCOME TAX CONSEQUENCES OF THE TRANSACTION

The following discussion summarizes the material federal income tax
considerations relevant to the merger that are generally applicable to holders
of CogenAmerica common stock and those options to purchase CogenAmerica common
stock that were granted by CogenAmerica or any of its subsidiaries as
compensation for services. This discussion is based on currently existing
provisions of the Internal Revenue Code, existing and proposed Treasury
Regulations and current administrative rulings and court decisions, all of which
are subject to change. Any change, which may or may not be retroactive, could
alter the tax consequences to the holders of the CogenAmerica common stock or
options as described here. Special tax consequences not described below may be
applicable to particular classes of taxpayers, including financial institutions,
broker-dealers, persons who are not citizens or residents of the United States
or who are foreign corporations, foreign partnerships or foreign estates or
trusts and stockholders who acquired CogenAmerica common stock through the
exercise of options or otherwise as compensation prior to the effective time of
the merger.

The conversion of the CogenAmerica common stock at the effective time of
the merger into the right to receive the merger consideration of $25.00 per
share in cash will be a taxable transaction for federal income tax purposes and
may also be a taxable transaction under applicable state and other tax laws. In
general, a stockholder will recognize gain or loss equal to the difference
between the tax basis of the CogenAmerica common stock and the amount of merger
consideration received in exchange for the CogenAmerica common stock. The gain
or loss will be treated as capital gain or loss if the CogenAmerica common stock
is a capital asset in the hands of the stockholder.

The receipt of the consideration for options (that were granted by
CogenAmerica or any of its subsidiaries as compensation for services) upon
delivery to the Payment Agent of an option termination agreement will be taxable
as ordinary income for federal and state income and other tax purposes. The
consideration for such options will be paid to the holders of such options net
of withholding and other applicable taxes.

The federal income tax consequences set forth above are for general
information only. Each stockholder and each holder of options is urged to
consult his or her own tax advisor to determine the particular tax consequences
to him or her of the merger, including the applicability and effect of state and
other tax laws.

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FINANCING OF THE MERGER; SOURCE OF FUNDS

Calpine has represented in the merger agreement that it has sufficient
capital resources necessary to perform its obligations under the merger
agreement. Calpine intends to finance the transaction with working capital funds
and borrowings under existing credit facilities.

ANTICIPATED ACCOUNTING TREATMENT

CogenAmerica believes that the merger will be accounted for by Calpine
using the purchase method of accounting in accordance with generally accepted
accounting principles.

APPRAISAL RIGHTS

If the merger is consummated, holders of shares of CogenAmerica common
stock are entitled to appraisal rights under Section 262 of the DGCL, provided
that they comply with the conditions established by Section 262.

Section 262 is reprinted in its entirety as Appendix D to this proxy
statement. The following discussion is not a complete statement of the law
relating to appraisal rights and is qualified in its entirety by reference to
Appendix D. This discussion and Appendix D should be reviewed carefully by any
stockholder who wishes to exercise statutory appraisal rights or who wishes to
preserve the right to do so, as failure to comply with the procedures set forth
herein or therein will result in the loss of appraisal rights.

A record holder of shares of CogenAmerica common stock who makes the demand
described below with respect to such shares, who continuously is the record
holder of such shares through the effective time of the merger, who otherwise
complies with the statutory requirements of Section 262 and who neither votes in
favor of the merger nor consents thereto in writing will be entitled, in lieu of
the $25.00 cash per share of CogenAmerica common stock to be paid in the merger,
to an appraisal by the Delaware Court of Chancery (the "Delaware Court") of the
fair value of his or her shares of CogenAmerica common stock. All references in
this summary of appraisal rights to a "stockholder" or "holders of shares of
common stock" are to the record holder or holders of shares of CogenAmerica
common stock. Except as set forth herein, stockholders of CogenAmerica will not
be entitled to appraisal rights in connection with the merger.

VOTING AGAINST, ABSTAINING FROM VOTING OR FAILING TO VOTE ON APPROVAL AND
ADOPTION OF THE MERGER WILL NOT CONSTITUTE A DEMAND FOR APPRAISAL WITHIN THE
MEANING OF SECTION 262 OF THE DGCL.

Under Section 262, where a merger is to be submitted for approval at a
meeting of stockholders, such as the special meeting, not less than 20 days
prior to the meeting a constituent corporation must notify each of the holders
of its stock for whom appraisal rights are available that such appraisal rights
are available and include in each such notice a copy of Section 262. This proxy
statement constitutes such notice to the record holders of CogenAmerica common
stock.

Holders of shares of CogenAmerica common stock who desire to exercise their
appraisal rights must not vote in favor of the merger and must deliver a
separate written demand for appraisal to CogenAmerica prior to the vote by the
stockholders of

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CogenAmerica on the merger. A demand for appraisal must be executed by or on
behalf of the stockholder of record and must reasonably inform CogenAmerica of
the identity of the stockholder of record and that such stockholder intends
thereby to demand appraisal of the CogenAmerica common stock. A proxy or vote
against the merger will not by itself constitute such a demand. Within ten days
after the effective time of the merger, CogenAmerica must provide notice of the
effective time of the merger to all stockholders who have complied with Section
262.

A stockholder who elects to exercise appraisal rights should mail or
deliver his or her written demand to: Cogeneration Corporation of America,
Attention: Thomas L. Osteraas, General Counsel and Secretary, One Carlson
Parkway, Suite 240, Minneapolis, Minnesota 55447-4454.

A person having a beneficial interest in shares of CogenAmerica common
stock that are held of record in the name of another person, such as a broker,
fiduciary, depositary or other nominee, must act promptly to cause the record
holder to follow the steps summarized herein properly and in a timely manner to
perfect appraisal rights. If the shares of CogenAmerica common stock are owned
of record by a person other than the beneficial owner, including a broker,
fiduciary (such as a trustee, guardian or custodian), depositary or other
nominee, such demand must be executed by or for the record owner. If the shares
of CogenAmerica common stock are owned of record by more than one person, as in
a joint tenancy or tenancy in common, such demand must be executed by or for all
joint owners. An authorized agent, including an agent for two or more joint
owners, may execute the demand for appraisal for a stockholder of record;
however, the agent must identify the record owner and expressly disclose the
fact that, in exercising the demand, such person is acting as agent for the
record owner. If a stockholder holds shares of CogenAmerica common stock through
a broker who in turn holds the shares through a central securities depository
nominee such as Cede & Co., a demand for appraisal of such shares must be made
by or on behalf of the depository nominee and must identify the depository
nominee as record holder.

A record holder, such as a broker, fiduciary, depositary or other nominee
who holds shares of CogenAmerica common stock as a nominee for others, may
exercise appraisal rights with respect to the shares held for all or less than
all beneficial owners of shares as to which such person is the record owner. In
such case, the written demand must set forth the number of shares covered by
such demand. Where the number of shares is not expressly stated, the demand will
be presumed to cover all shares of CogenAmerica common stock outstanding in the
name of such record owner.

Within 120 days after the effective time of the merger, either CogenAmerica
or any stockholder who has complied with the required conditions of Section 262
may file a petition in the Delaware Court, with a copy served on CogenAmerica in
the case of a petition filed by a stockholder, demanding a determination of the
fair value of the shares of all dissenting stockholders. There is no present
intent on the part of CogenAmerica to file an appraisal petition and
stockholders seeking to exercise appraisal rights should not assume that
CogenAmerica will file such a petition or that CogenAmerica will initiate any
negotiations with respect to the fair value of such shares. Accordingly, holders
of CogenAmerica common stock who desire to have their shares appraised should
initiate any petitions necessary for the perfection of their appraisal rights
within the time periods and in the manner prescribed in Section 262. Within 120
days after the effective time of the merger, any stockholder who has theretofore
complied with the applicable provisions of Section 262 will be entitled, upon
written request, to receive from CogenAmerica a

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statement setting forth the aggregate number of shares of CogenAmerica common
stock not voting in favor of the merger and with respect to which demands for
appraisal were received by CogenAmerica and the number of holders of such
shares. Such statement must be mailed (i) within 10 days after the written
request therefor has been received by CogenAmerica or (ii) within 10 days after
the expiration of the period for the delivery of demands as described above,
whichever is later.

If a petition for an appraisal is filed timely, at the hearing on such
petition, the Delaware Court will determine which stockholders are entitled to
appraisal rights. The Delaware Court may require the stockholders who have
demanded an appraisal for their shares and who hold stock represented by
certificates to submit their certificates of stock to the Register in Chancery
for notation thereon of the pendency of the appraisal proceedings; and if any
stockholder fails to comply with such direction, the Delaware Court may dismiss
the proceedings as to such stockholder. Where proceedings are not dismissed, the
Delaware Court will appraise the shares of CogenAmerica common stock owned by
such stockholders, determining the fair value of such shares exclusive of any
element of value arising from the accomplishment or expectation of the merger,
together with a fair rate of interest, if any, to be paid upon the amount
determined to be the fair value.

Although CogenAmerica believes that the merger consideration for each share
of CogenAmerica common stock held by a stockholder is fair, no representation is
made as to the outcome of the appraisal of fair value as determined by the
Delaware Court and stockholders should recognize that such an appraisal could
result in a determination of a value higher or lower than, or the same as, the
merger consideration. Moreover, CogenAmerica does not anticipate offering more
than the merger consideration to any stockholder exercising appraisal rights and
reserves the right to assert, in any appraisal proceeding, that, for purposes of
Section 262, the "fair value" of a share of CogenAmerica common stock is less
than the merger consideration. In determining "fair value," the Delaware Court
is required to take into account all relevant factors. In Weinberger v. UOP,
Inc., the Delaware Supreme Court discussed the factors that could be considered
in determining fair value in an appraisal proceeding, stating that "proof of
value by any techniques or methods which are generally considered acceptable in
the financial community and otherwise admissible in court" should be considered
and that "fair price obviously requires consideration of all relevant factors
involving the value of a company." The Delaware Supreme Court has stated that in
making this determination of fair value the court must consider market value,
asset value, dividends, earnings prospects, the nature of the enterprise and any
other facts which could be ascertained as of the date of the merger which throw
any light on future prospects of the merged corporation. Section 262 provides
that fair value is to be "exclusive of any element of value arising from the
accomplishment or expectation of the merger." In Cede & Co. v. Technicolor,
Inc., the Delaware Supreme Court stated that such exclusion is a "narrow
exclusion that does not encompass known elements of value," but which rather
applies only to the speculative elements of value arising from such
accomplishment or expectation. In Weinberger, the Delaware Supreme Court
construed Section 262 to mean that "elements of future value, including the
nature of the enterprise, which are known or susceptible of proof as of the date
of the merger and not the product of speculation, may be considered."

Delaware courts have decided that the statutory appraisal remedy, depending
on factual circumstances, may or may not be a dissenter's exclusive remedy.
Several decisions by the Delaware courts have held that a controlling
stockholder has a fiduciary duty to the other stockholders which requires that
the merger be "entirely fair" to such other

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stockholders. In determining whether a merger is fair to minority stockholders,
the Delaware courts have considered among other things, the type of and amount
of consideration to be received by stockholders and whether there was fair
dealing among the parties. The Delaware Supreme Court stated in Weinberger, that
although the remedy ordinarily available in a merger that is found not to be
"fair" to minority stockholders is the right to appraisal described above, such
appraisal remedy may not be adequate "in certain cases, particularly where
fraud, misrepresentations, self-dealing, deliberate waste of corporate assets,
or gross and palpable overreaching are involved,"and that in such cases the
Delaware Court would be free to fashion any form of appropriate relief.

Stockholders considering seeking appraisal should recognize that the fair
value of their shares determined under Section 262 could be more than, the same
as or less than the consideration they are entitled to receive pursuant to the
merger agreement if they do not seek appraisal of their shares. The Delaware
Court will determine the amount of interest, if any, to be paid on amounts to be
received by persons whose shares have been appraised. The cost of the appraisal
proceeding may be determined by the Delaware Court and taxed against the parties
as the Delaware Court deems equitable in the circumstances. However, costs do
not include attorneys' and expert witness fees. Each dissenting stockholder is
responsible for his or her attorneys' and expert witness expenses, although,
upon application of a dissenting stockholder of CogenAmerica, the Delaware Court
may order that all or a portion of the expenses incurred by any dissenting
stockholder in connection with the appraisal proceeding, including without
limitation, reasonable attorneys' fees and the fees and expenses of experts, be
charged pro rata against the value of all shares of stock entitled to appraisal.

Any stockholder who has duly demanded appraisal in compliance with Section
262 will not, after the effective time of the merger, be entitled to vote for
any purpose any shares subject to such demand or to receive payment of dividends
or other distributions on such shares, except for dividends or distributions
payable to stockholders of record at a date prior to the effective time of the
merger.

At any time within 60 days after the effective time of the merger, any
stockholder will have the right to withdraw such demand for appraisal and to
accept the terms offered in the merger; after this period, the stockholder may
withdraw such demand for appraisal only with the consent of CogenAmerica. If no
petition for appraisal is filed with the Delaware Court within 120 days after
the effective time of the merger, stockholders' rights to appraisal shall cease,
and all holders of shares of CogenAmerica common stock will be entitled to
receive the consideration offered pursuant to the merger agreement. Inasmuch as
CogenAmerica has no obligation to file a petition for an appraisal, and
CogenAmerica has no present intention to do so, any stockholder who desires such
a petition to be filed is advised to file it on a timely basis. Any stockholder
may withdraw such stockholders' demand for appraisal by delivering to
CogenAmerica a written withdrawal of his or her demand for appraisal and
acceptance of the merger consideration, except (i) that any such attempt to
withdraw made more than 60 days after the effective time of the merger will
require written approval of CogenAmerica and (ii) that no appraisal proceeding
in the Delaware Court shall be dismissed as to any stockholder without the
approval of the Delaware Court, and such approval may be conditioned upon such
terms as the Delaware Court deems just.

A stockholder will fail to perfect his or her right of appraisal if he or
she (a) does not deliver a written demand for appraisal to CogenAmerica prior to
the vote for approval and adoption of the merger agreement, (b) votes his or her
shares of CogenAmerica common

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stock in favor of approval and adoption of the merger agreement, (c) does not
file a petition for appraisal within 120 days after the effective time of the
merger, or (d) delivers to the company both a written withdrawal of his or her
demand for appraisal and an acceptance of the terms of the merger agreement,
except that any such attempt to withdraw such demand not made within 60 days
after the effective time of the merger requires the written approval of
CogenAmerica. If any stockholder who properly demands appraisal of such
stockholder's shares of CogenAmerica common stock under Section 262 fails to
perfect, or effectively withdraws or loses, such stockholder's right to
appraisal, the shares of CogenAmerica common stock of such stockholder will be
converted into the right to receive $25.00 per share in cash in accordance with
the merger agreement.

Cash received pursuant to the exercise of appraisal rights may be subject
to federal or state income tax. See "Federal Income Tax Consequences of the
Transaction" (page 45).

ANY HOLDER OF COGENAMERICA COMMON STOCK WHO FAILS TO COMPLY FULLY WITH THE
STATUTORY PROCEDURE SUMMARIZED ABOVE WILL FORFEIT HIS OR HER APPRAISAL RIGHTS
UNDER THE DGCL AND WILL RECEIVE THE MERGER CONSIDERATION FOR HIS OR HER SHARES.
SEE APPENDIX D.

IN VIEW OF THE COMPLEXITY OF THESE PROVISIONS IN THE DGCL, STOCKHOLDERS WHO
ARE CONSIDERING DISSENTING FROM THE APPROVAL AND ADOPTION OF THE MERGER
AGREEMENT AND EXERCISING THEIR RIGHTS UNDER SECTION 262 SHOULD CONSULT THEIR
LEGAL ADVISORS.

SUMMARY OF MATERIAL FEATURES OF THE CALPINE/NRG AGREEMENT

Concurrently with the execution of the merger agreement, Calpine,
Acquisition Sub and NRG entered into the Calpine/NRG Agreement on August 26,
1999. The Calpine/ NRG Agreement provides that, subject to the terms and
conditions thereof, immediately prior to the consummation of the merger:

- NRG will contribute to Acquisition Sub a number of shares of CogenAmerica
common stock equal in value to (i) at least 20% of the total equity value
of CogenAmerica less (ii) the value of the CogenAmerica stock options
held by NRG employees which have been or will be cancelled prior to the
merger, in exchange for 20% of the ownership interest in Acquisition Sub;
and

- Calpine will contribute to Acquisition Sub cash equal to 80% of the total
equity value of CogenAmerica in exchange for 80% of the ownership
interest in Acquisition Sub. The total equity value of CogenAmerica is
defined as the sum of (i) the total number of issued and outstanding
shares of CogenAmerica common stock immediately prior to completion of
the merger multiplied by $25.00 and (ii) the aggregate amount of the
excess of $25.00 per share over the exercise price per share of each of
the outstanding CogenAmerica options.

Pursuant to the Calpine/NRG Agreement, Calpine has also agreed to
contribute cash, in the form of a loan, sufficient to satisfy certain
obligations of CogenAmerica. Upon consummation of the merger, NRG shall own 20%
and Calpine shall own 80% of the outstanding shares of CogenAmerica common
stock. The obligations of Calpine and NRG to make their respective capital
contributions described above is conditioned upon the

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satisfaction or waiver of all of the closing conditions set forth in the merger
agreement, including the approval and adoption of the merger agreement by
CogenAmerica stockholders.

The Calpine/NRG Agreement provides that the Board of Directors of the
surviving corporation (i.e., CogenAmerica following the merger) will consist of
no more than seven directors with one director being appointed by NRG. In
addition, the consent of NRG is required for the surviving corporation or its
subsidiaries to take certain actions including, without limitation, actions
relating to:

- the issuance of securities;

- the sale or disposition of subsidiaries or assets;

- amendments to the certificate of incorporation or by-laws;

- mergers or consolidations with third parties; and

- certain agreements with affiliates.

The Calpine/NRG Agreement prohibits Calpine and NRG from transferring their
respective shares of CogenAmerica common stock of the surviving corporation for
a period of three years after completion of the merger without the prior written
consent of the other stockholder, which consent cannot be unreasonably withheld
or delayed.

Pursuant to the Calpine/NRG Agreement, NRG has granted Calpine an
irrevocable proxy with respect to all of the shares of CogenAmerica common stock
held by it (constituting 45.3% of the outstanding shares) to vote such shares in
favor of approval of the merger agreement and charter amendment at a duly
convened meeting of CogenAmerica's stockholders for such purpose. NRG has also
agreed that prior to the consummation of the merger, it shall not (i) solicit
third parties with respect to sale of shares of CogenAmerica common stock owned
by NRG and (ii) transfer the shares of CogenAmerica common stock owned by NRG
except as contemplated by the Calpine/ NRG Agreement.

NRG and Calpine have agreed that prior to the consummation of the merger,
each party shall use reasonable efforts to take all actions and to do all things
necessary, proper or advisable in order to permit the consummation of the
merger. Calpine has agreed not to cause the merger agreement to be amended or
waive any of its rights thereunder in any way that would be materially adverse
to NRG without NRG's prior written consent.

In the Calpine/NRG Agreement, NRG has granted Calpine with a right of first
refusal to acquire the shares of surviving corporation stock held by NRG.
Further, the Calpine/NRG Agreement provides that (i) Calpine can require that
NRG sell its shares in the event Calpine sells all or substantially all of its
shares in the surviving corporation (i.e., drag-along rights), and (ii) NRG can
require that its shares of surviving corporation stock be included in a
transaction in which Calpine sells any of its shares in the surviving
corporation to a third party (i.e., tag-along rights). The Calpine/NRG Agreement
also provides that Calpine shall have the right to acquire NRG's 20% interest in
CogenAmerica during the 365-day period commencing on the third anniversary of
the closing of the merger for the fair market value of the interest as
determined by an independent investment bank. Pursuant to the Calpine/NRG
Agreement, the surviving corporation is required to pay Calpine certain
management fees for management services to be provided by Calpine after
consummation of the merger through the fourth anniversary thereof.

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PROPOSAL 2: THE CHARTER AMENDMENT

SUMMARY OF THE CHARTER AMENDMENT

Article VII of CogenAmerica's Amended and Restated Certificate of
Incorporation places certain restrictions on the transfer of shares of
CogenAmerica common stock by any person that owns more than 5% of the
outstanding shares of CogenAmerica common stock until April 30, 2002. The
purpose of Article VII is to assure that the net operating loss carryforwards
("NOLs") of CogenAmerica will not be adversely affected by the transfer of
shares by such a holder. Article VII would require NRG to provide certain legal
opinions or that the CogenAmerica Board of Directors make certain determinations
as to the continued availability of the NOLs. Article VII provides an exception
for these requirements in the event the transfer is pursuant to a tender offer
for at least 66 2/3% of the outstanding shares of CogenAmerica common stock that
is followed by a merger in which the remaining stockholders receive the same
consideration as the stockholders that tendered their shares in the tender
offer. Since the merger does not technically fit within the express language of
Article VII and it may be difficult to comply with the requirements of Article
VII in connection with the transfer of shares by NRG to Acquisition Sub
immediately prior to completion of the merger, the CogenAmerica Board of
Directors has approved and recommends that stockholders approve an amendment to
Article VII that will permit NRG to transfer shares of CogenAmerica common stock
to Acquisition Sub immediately prior to completion of the merger in order for
NRG to retain a 20% equity interest in CogenAmerica after the merger. A copy of
the charter amendment is attached as Appendix B to this proxy statement.

THE COGENAMERICA BOARD OF DIRECTORS HAS UNANIMOUSLY APPROVED THE CHARTER
AMENDMENT, AND THE COGENAMERICA BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT
THE STOCKHOLDERS VOTE FOR APPROVAL OF THE CHARTER AMENDMENT.

MANAGEMENT OF COGENAMERICA

Information concerning the management of CogenAmerica, the names, principal
occupations and employment history of the directors and executive officers of
CogenAmerica, is provided in CogenAmerica's Annual Report on Form 10-K for the
fiscal year ended December 31, 1998 that is incorporated by reference in this
proxy statement (SEC File No. 1-9208). All of the directors and executive
officers of CogenAmerica are citizens of the United States. The business
addresses of each director and executive officer of CogenAmerica is listed in
footnote 1 to the table under "Interests in Securities of CogenAmerica."

INTEREST IN SECURITIES OF COGENAMERICA

The following table sets forth certain information with respect to the
beneficial ownership of the CogenAmerica common stock as of November 12, 1999 by
(a) all persons known to CogenAmerica to own beneficially more than 5% of the
CogenAmerica common stock, (b) each executive officer and each director of
CogenAmerica, (c) all executive officers and directors of CogenAmerica as a
group, (d) the Employee Savings Plan (401(k) Plan) of CogenAmerica, (e) NRG and
Calpine, and (f) four officers or former officers of NRG who are directors of
CogenAmerica. Except as set forth below, no

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other executive officer or director of Calpine, Acquisition Sub or NRG or its
ultimate parent, NSP, beneficially owns CogenAmerica common stock. As of
November 12, 1999, there were 6,857,269 outstanding shares of CogenAmerica
common stock. Information presented with respect to options for purposes of this
proxy statement assumes that, as provided in the merger agreement on the date of
completion of the merger all options that are then exercisable, including the
acceleration of vesting as a result of the merger, will be converted into the
right to receive a cash amount equal to the excess, if any, of $25.00 over the
exercise price of the options multiplied by the number of shares of CogenAmerica
common stock so exercisable under the options. Value of stock options is the
aggregate cash amount payable to each owner of options upon completion of the
merger.

SHARES BENEFICIALLY OWNED(1)
------------------------------------------
PERCENTAGE OF
OUTSTANDING
NUMBER OF      SHARES AS OF      NUMBER OF    VALUE OF
NAME AND ADDRESS             SHARES     NOVEMBER 12, 1999    OPTIONS     OPTIONS
----------------           ----------   -----------------   ---------   ----------

NRG Energy, Inc.(2)...............   3,106,612         45.3%               --            --
1221 Nicollet Mall, Suite 700
Minneapolis, MN 55403-2445
Wexford Capital Partners II,
L.P.(3).........................     443,976          6.5%               --            --
411 West Putnam Avenue
Greenwich, CT 06380
Calpine Corporation(2)............   3,106,612         45.3%
50 West San Fernando Street
San Jose, CA 95113
David H. Peterson(4)(14)..........      31,000            *            30,000    $  586,875
Julie A. Jorgensen(5).............     231,500          3.3%          230,000     3,163,750
Mark Liddell(6)...................      10,000            *            10,000       126,250
Lawrence I. Littman(7)............      30,070            *            30,000       586,875
Craig A. Mataczynski(8)(14).......      30,500            *            30,000       586,875
Michael O'Sullivan................          --           --                --
Charles J. Thayer(9)..............      50,000            *            10,000       195,625
Ronald J. Will(10)(14)............      32,500            *            30,000       586,875
Timothy P. Hunstad(11)............     112,500          1.6%          112,000     1,922,938
Thomas L. Osteraas(12)............      45,000            *            45,000       604,687
Richard C. Stone(13)..............     120,000          1.7%          120,000     1,121,875
Directors and Executive Officers
of CogenAmerica as a group......     683,070          9.1%

---------------
*  Represents less than 1.0% of the outstanding shares of CogenAmerica common
stock.

(1) Under the rules of the SEC, a person is deemed to be a beneficial owner of
a security if he or she has or shares the power to vote or to direct the
voting of such security, or the power to dispose or to direct the
disposition of such security. A person is also deemed to be a beneficial
owner of any securities that such person has the right to acquire
beneficial ownership of within 60 days as well as any securities

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owned by such person's spouse, children or relatives living in the same
household. Accordingly, more than one person may be deemed to be a
beneficial owner of the same securities. The address of Messrs. Peterson,
Mataczynski, O'Sullivan and Will is 1221 Nicollet Mall, Suite 700,
Minneapolis, Minnesota 55403-2445. The address of Ms. Jorgensen and Messrs.
Hunstad, Osteraas and Stone is One Carlson Parkway, Suite 240, Minneapolis,
Minnesota 55447-4454. The address of Mr. Liddell is 6307 Waterford
Boulevard, Suite 100, Oklahoma City, Oklahoma 73118. The address of Mr.
Littman is 1660 S A1, Apt. 212, Jupiter, Florida 33477-8449. The address of
Mr. Thayer is 420 Isle of Capri Drive, Fort Lauderdale, Florida 33301-2438.

(2) Calpine may be deemed to be the beneficial holder of securities owned by
NRG as a result of entering into the Calpine/NRG Agreement. Under the terms
of the Calpine/NRG Agreement, NRG has granted Calpine an irrevocable proxy
with respect to all of the shares of CogenAmerica common stock held by NRG
to vote those shares in favor of approval and adoption of the merger
agreement and the charter amendment at a duly convened meeting of
CogenAmerica's stockholders.

(3) Includes 348,672 shares owned by Wexford Capital Partners II, LP and 95,304
shares owned by Wexford Overseas Partners Fund I, LP. Through an investment
management agreement, Wexford Management LLC, which manages the funds, has
sole voting and investment power of the funds. This information is as of
the date set forth in and based on the Schedule 13D filed May 8, 1997 and
other information furnished to CogenAmerica by Wexford Management LLC.

(4) Includes 30,000 shares issuable upon exercise of stock option at an
exercise price of $5.4375 per share.

(5) Represents 300 shares owned jointly with spouse and 1,200 beneficially
owned by Ms. Jorgensen and includes 30,000 shares issuable upon exercise of
stock option at an exercise price of $9.125 per share and 200,000 shares
issuable upon exercise of stock option at an exercise price of $11.5625 per
share, including 100,000 shares which will become vested and exercisable as
a result of the completion of the merger.

(6) Includes 10,000 shares issuable upon exercise of stock option at an
exercise price of $12.375 per share which will become vested and
exercisable as a result of the completion of the merger.

(7) Includes 30,000 shares issuable upon exercise of stock option at an
exercise price of $5.4375 per share.

(8) Represents 500 shares beneficially owned by Mr. Mataczynski and includes
30,000 shares issuable upon exercise of stock option at an exercise price
of $5.4375 per share.

(9) Represents 50,000 shares beneficially owned by Mr. Thayer and includes
10,000 shares issuable upon exercise of stock option at an exercise price
of $5.4375 per share.

(10) Represents 2,500 shares held jointly with spouse and includes 30,000 shares
issuable upon exercise of stock option at an exercise price of $5.4375 per
share.

(11) Represents 500 shares owned by Mr. Hunstad and includes 75,000 shares
issuable upon exercise of stock option at an exercise price of $5.4375 per
share, 17,000 shares issuable upon exercise of stock option at an exercise
price of $14.00 per share, including 11,333 shares which will become vested
and exercisable as a result of the merger, and 20,000 shares issuable upon
exercise of stock option at an exercise price

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of $11.5625 per share, all of which will become vested and exercisable as a
result of the completion of the merger.

(12) Includes 45,000 shares issuable upon exercise of stock options at an
exercise price of $11.5625, all of which will become vested and exercisable
as a result of the completion of the merger.

(13) Includes 100,000 shares issuable upon exercise of stock option at an
exercise price of $16.46875 per share, including 86,667 shares which will
become vested and exercisable as a result of the completion of the merger,
and 20,000 shares issuable upon exercise of stock option at an exercise
price of $11.5625 per share, all of which will become vested and
exercisable as a result of the completion of the merger.

(14) Current NRG corporate policy prohibits NRG employees from receiving the
economic benefit of options granted to them in their capacity as a director
of CogenAmerica. The NRG employees who currently serve as directors of
CogenAmerica and were previously granted stock options in their capacity as
directors of CogenAmerica, have agreed to the cancellation of their stock
options. The NRG employees who serve as directors of CogenAmerica will
receive no cash payment for these options.

CERTAIN TRANSACTIONS IN COMMON STOCK AND STOCK OPTIONS

No transactions in CogenAmerica common stock or options have been effected
during the 60 days preceding the date of this proxy statement by CogenAmerica or
by the persons named under the caption "Interest in Securities of CogenAmerica"
except as provided in the Calpine/NRG Agreement described under the caption
"Summary of Calpine/NRG Agreement."

EXPENSES OF THE TRANSACTION

The aggregate fees and expenses paid and estimated to be paid by
CogenAmerica in connection with the merger and related transactions are as
follows:

Investment Banking Fee..............................  $ 3,418,500(1)
Legal and Accounting................................      775,000
Printing and Distribution...........................       50,000
SEC and Regulatory Filings..........................       36,635
Miscellaneous.......................................       19,865
-----------
Total..........................................  $ 4,300,000
===========

---------------
(1) DLJ is also entitled to reimbursement of out-of-pocket expenses incurred in
connection with its engagement (including reasonable fees and expenses of
counsel).

INDEPENDENT ACCOUNTANTS

PricewaterhouseCoopers LLP, independent certified public accountants, are
the independent accountants for CogenAmerica. A representative of
PricewaterhouseCoopers LLP, will be available at the special meeting to answer
questions.

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WHERE YOU CAN FIND MORE INFORMATION

CogenAmerica files annual, quarterly and special reports, proxy statements
and other information with the SEC. You may read and copy any such reports,
statements or other information at the SEC's public reference rooms in
Washington, DC, New York, New York and Chicago, Illinois. Please call the SEC at
1-800-SEC-0330 for further information on the public reference rooms.
CogenAmerica's SEC filings are also available to the public from commercial
document retrieval services and at the world wide web site maintained by the SEC
at http:\\www.sec.gov. Reports, proxy statements and other information
concerning CogenAmerica also may be inspected at the offices of the National
Association of Securities Dealers, Inc., 1735 K Street, N.W., Washington, DC
20006.

The SEC allows CogenAmerica to incorporate by reference information into
this document, which means that CogenAmerica can disclose important information
to you by referring you to another document filed separately with the SEC. The
information incorporated by reference is deemed to be a part of this document,
except for any information superseded by information contained directly in this
document. This document incorporates by reference certain documents that
CogenAmerica has previously filed with the SEC. These documents contain
important business information about CogenAmerica and its financial condition.

CogenAmerica may have sent to you some of the documents incorporated by
reference, but you can obtain any of them through CogenAmerica or the SEC or the
SECs world wide web site described above. Documents incorporated by reference
are available from CogenAmerica without charge, excluding all exhibits, unless
specifically incorporated by reference as an exhibit to this document.
Stockholders may obtain documents incorporated by reference in this document by
requesting them in writing or by telephone at the following address:

Cogeneration Corporation of America
One Carlson Parkway, Suite 240
Minneapolis, Minnesota 55447-4454
Attention: Thomas L. Osteraas
Telephone: (612) 745-7900

Calpine, Acquisition Sub and NRG have filed a Schedule 13E-3 with the SEC
with respect to the merger. The Schedule 13E-3, including any amendments and
exhibits filed or incorporated by reference as a part thereof, is available for
inspection or copying as set forth above. Statements contained in this proxy
statement or in any document incorporated herein by reference as to the contents
of any contract or other document referred to herein or therein are not
necessarily complete and in each instance reference is made to such contract or
other document filed as an exhibit to the Schedule 13E-3 or such other document,
and each such statement shall be deemed qualified in its entirely by such
reference.

IF YOU WOULD LIKE TO REQUEST DOCUMENTS FROM COGENAMERICA, PLEASE DO SO AT
LEAST FIVE BUSINESS DAYS BEFORE THE DATE OF THE SPECIAL MEETING IN ORDER TO
RECEIVE TIMELY DELIVERY OF SUCH DOCUMENTS PRIOR TO THE SPECIAL MEETING.

You should rely only on the information contained or incorporated by
reference in this document to vote your shares at the special meeting.
CogenAmerica has not authorized anyone to provide you with information that is
different from what is contained in this

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document. This document is dated November 15, 1999. You should not assume that
the information contained in this document is accurate as of any date other than
that date, and the mailing of this document to stockholders does not create any
implication to the contrary. This proxy statement does not constitute a
solicitation of a proxy in any jurisdiction where, or to or from any person to
whom, it is unlawful to make such proxy solicitation in such jurisdiction.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The following documents previously filed with the SEC by CogenAmerica (SEC
File No. 1-9208) are incorporated by reference in this proxy statement:

(i) CogenAmerica's Annual Report on Form 10-K for the fiscal year
ended December 31, 1998;

(ii) CogenAmerica's Quarterly Report on Form 10-Q for the quarter
ended March 31, 1999;

(iii) CogenAmerica's Quarterly Report on Form 10-Q for the quarter
ended June 30, 1999; and

(iv) CogenAmerica's Current Report on Form 8-K filed on September 2,
1999.

All documents filed by CogenAmerica with the SEC pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act after the date of this document
and prior to the date of the special meeting will be deemed to be incorporated
by reference in this document. Information filed with the SEC in future
documents will automatically update and supersede the information in this
document.

STOCKHOLDER PROPOSALS

If the merger is not completed for any reason, proposals of stockholders
intended to be presented at the 2000 Annual Meeting of Stockholders must be
received by Thomas L. Osteraas, Secretary and General Counsel, Cogeneration
Corporation of America, One Carlson Parkway, Suite 240, Minneapolis, Minnesota
55447-4454 on or prior to January 20, 2000 to be eligible for inclusion in
CogenAmerica's proxy statement and proxy card relating to that meeting.
CogenAmerica is not required to include in its proxy statement and proxy card
for the 2000 Annual Meeting any stockholder proposals which do not meet all of
the requirements then in effect for inclusion.

OTHER MATTERS

Management knows of no other business to be presented at the special
meeting. If other matters do properly come before the meeting, or any
adjournment or adjournments thereof, it is the intention of the persons named in
the proxy to vote on such matters according to their best judgment unless the
authority to do so is withheld in such proxy.

By Order of the Board of Directors

JULIE A. JORGENSEN
Julie A. Jorgensen
President and Chief Executive Officer

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CAUTIONARY STATEMENT CONCERNING
FORWARD-LOOKING INFORMATION

THIS PROXY STATEMENT, THE SCHEDULE 13E-3 TRANSACTION STATEMENT FILED WITH
THE SECURITIES AND EXCHANGE COMMISSION AND OTHER STATEMENTS MADE FROM TIME TO
TIME BY COGENAMERICA, CALPINE, ACQUISITION SUB, NRG OR THEIR REPRESENTATIVES
CONTAIN FORWARD-LOOKING STATEMENTS. THOSE STATEMENTS INCLUDE STATEMENTS
REGARDING THE INTENT, BELIEF OR CURRENT EXPECTATIONS OF COGENAMERICA, CALPINE,
ACQUISITION SUB AND NRG AND MEMBERS OF THEIR RESPECTIVE MANAGEMENT TEAMS, AS
WELL AS THE ASSUMPTIONS ON WHICH SUCH STATEMENTS ARE BASED. SUCH FORWARD-LOOKING
STATEMENTS ARE NOT GUARANTEES OF FUTURE PERFORMANCE AND INVOLVE RISKS AND
UNCERTAINTIES. ACTUAL RESULTS MAY DIFFER MATERIALLY FROM THOSE CONTEMPLATED BY
SUCH FORWARD-LOOKING STATEMENTS. IMPORTANT FACTORS CURRENTLY KNOWN TO MANAGEMENT
OF COGENAMERICA, CALPINE, ACQUISITION SUB AND NRG THAT COULD CAUSE ACTUAL
RESULTS TO DIFFER MATERIALLY FROM THOSE IN FORWARD-LOOKING STATEMENTS INCLUDE,
BUT ARE NOT LIMITED TO, THE RISKS DETAILED IN THIS PROXY STATEMENT AND THE
SCHEDULE 13E-3 TRANSACTION STATEMENT, AND THOSE FACTORS SET FORTH FROM TIME TO
TIME IN REPORTS OF COGENAMERICA FILED WITH THE SECURITIES AND EXCHANGE
COMMISSION. THE PROTECTION FROM LIABILITY OF THE SAFE HARBOR FOR FORWARD-LOOKING
STATEMENTS CONTAINED IN THE PRIVATE SECURITIES REFORM ACT OF 1995 IS NOT
APPLICABLE TO THE INFORMATION CONTAINED IN THIS PROXY STATEMENT OR THE SCHEDULE
13E-3 TRANSACTION STATEMENT OR IN STATEMENTS INCORPORATED BY REFERENCE IN EITHER
DOCUMENT.

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