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                                  FIRST AMENDMENT
                                         TO
                                  CREDIT AGREEMENT



                           DATED AS OF FEBRUARY 12, 1999



                                      BETWEEN



                        COGENERATION CORPORATION OF AMERICA
                        (f/k/a NRG GENERATING (U.S.), INC.),
                                    AS BORROWER



                                        AND



                             MEESPIERSON CAPITAL CORP.,
                  AS ARRANGER, LENDER, AGENT AND SECURITY TRUSTEE




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                                  FIRST AMENDMENT
                                         TO
                                  CREDIT AGREEMENT

     THIS FIRST AMENDMENT TO CREDIT AGREEMENT (this "Amendment") is made as 
of the 12th day of February, 1999, between Cogeneration Corporation of 
America (f/k/a NRG Generating (U.S.), Inc.), as the Borrower, and MeesPierson 
Capital Corp., as the Arranger, the Lender, the Agent and the Security 
Trustee (in such collective capacity, "MPCC"), and amends and is supplemental 
to that certain Credit Agreement, dated as of December 17, 1997, between the 
Borrower, and MPCC (the "Credit Agreement").


                                    WITNESSETH:


     WHEREAS, the Borrower and the Lender desire to amend the Credit 
Agreement; and

     NOW, THEREFORE, in consideration of the premises and such other good and 
valuable consideration, the receipt and adequacy of which are hereby 
acknowledged by the Borrower and MPCC, it is hereby agreed as follows:

     1.   RULES OF CONSTRUCTION; DEFINITIONS.  Capitalized terms not 
otherwise defined herein shall have the meanings assigned to such terms in 
the Credit Agreement.

     2.   AMENDMENTS TO THE CREDIT AGREEMENT.  (a) Subject to the terms and 
conditions of this Amendment, Section 9.1(f) of the Credit Agreement is 
hereby amended and supplemented by inserting the following at the end of the 
Section:

     ; PROVIDED, HOWEVER, no Event of Default arises under this Section 
     9.1(f) as the result of either (i) the purported termination by PECO of 
     the Grays Ferry Power Purchase Agreements, (ii) the subsequent 
     declaration of an event of default under that certain Credit Agreement 
     (the "CHASE FACILITY"), dated as of March 1, 1996, among Grays Ferry, 
     the financial institutions party thereto and The Chase Manhattan Bank, 
     as agent for such financial institutions, or (iii) by reason of or due 
     to acceleration of the indebtedness under the Chase Facility and/or 
     enforcement of the lender's rights under the Chase Facility and/or any 
     other actions taken by PECO Energy Company or any other person or entity 
     under or allegedly as allowed by the Grays Ferry Power Purchase 
     Agreements and/or any other action taken by the lenders or any other 
     person or entity under or as allowed by the Chase Facility and/or events 
     or circumstances that result directly or indirectly from, are directly 
     or indirectly due to or are directly or indirectly caused by any or all 
     of the above, including without limitation action, events or 
     circumstances which with the passing 


<PAGE>

     of time, or both, would or could otherwise constitute an Event of Default 
     under the Credit Agreement.

     (b)  The Credit Agreement is hereby further amended by substituting the 
Schedule 2 attached hereto as Annex A in place of the existing Schedule 2.

     4.   BORROWER'S REPRESENTATIONS AND WARRANTIES.  Borrower represents 
that this Amendment has been duly authorized, executed and delivered by 
Borrower pursuant to its corporate powers and constitutes the legal, valid 
and binding obligation of Borrower.  After giving effect to the amendment set 
forth above in Section 2(a) above, as of the date hereof no Event of Default 
has occurred and is in effect, and each representation and warranty set forth 
in Section 2 of the Credit Agreement is hereby restated and affirmed as true 
and correct as of the date hereof.

     5.   CONDITIONS PRECEDENT.  The effectiveness of this Amendment shall be 
subject to the conditions precedent that the Agent shall have received the 
following, each in form and substance satisfactory to the Agent:

     (a)  this Amendment executed by each party hereto; and
     
     (b)  a fee in the amount of $187,500.00; and
     
     (c)  a written instruction from the Borrower to the Agent canceling the  
          undrawn commitment under the Facility

     6.   CONFIRMATION OF CREDIT AGREEMENT.  Except as herein expressly 
amended, the Credit Agreement is ratified and confirmed in all respects and 
shall remain in full force and effect in accordance with its terms.  Each 
reference in the Credit Agreement to "this Agreement" shall mean the Credit 
Agreement as amended by this Amendment, and as hereinafter amended or 
restated.

     7.   GOVERNING LAW.  THIS AMENDMENT SHALL BE CONSTRUED IN ACCORDANCE 
WITH AND GOVERNED BY THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO ITS 
CONFLICT OF LAW RULES.

     8.   COUNTERPARTS.  This Amendment may be executed in counterparts 
which, taken together, shall constitute a single document.

     9.   MODIFICATIONS IN WRITING.  No amendment, modifications, supplement, 
termination or waiver of this Amendment shall be effective unless the same 
shall be in writing and otherwise made in accordance with Section 17.5 of the 
Credit Agreement.

     10.  EFFECTIVENESS.  This amendment shall be effective as of January 1, 
1999.  Any payment of interest in excess of the non-default rate made by the 
Borrower during the month of January 1999 shall be applied towards the fee 
described in Section 5(b) hereof.


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     IN WITNESS WHEREOF, each of the Borrower and MPCC caused this Amendment 
to be executed by its duly authorized officer as of the 12th day of February, 
1999.

                         COGENERATION CORPORATION OF AMERICA,
                         as Borrower


                         By:  /s/  Timothy P. Hunstad
                            --------------------------------------------
                         Name:     Timothy P. Hunstad
                         Title:    V.P. and Chief Financial Officer


                         MEESPIERSON CAPITAL CORP.,
                         as Arranger, Lender, Agent and Security Trustee


                         By:  /s/  Hendrik Vroege           
                            --------------------------------------------
                         Name:     Hendrik Vroege
                         Title:    Managing Director


                         By:  /s/  Eugene Oliva                       
                            --------------------------------------------
                         Name:     Eugene Oliva
                         Title:    Assistant Vice President


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