FOURTH
      AMENDMENT TO REIMBURSEMENT AGREEMENT





THIS
      FOURTH AMENDMENT TO REIMBURSEMENT AGREEMENT, dated as of April 12, 2006 (this
      “ Amendment ”),
      to
      the Existing Reimbursement Agreement (as defined below) is made by PPL ENERGY
      SUPPLY, LLC, a Delaware limited liability company (the “ Account
      Party ”),
      and
      certain of the Lenders (such capitalized term and other capitalized terms used
      in this preamble and the recitals below to have the meanings set forth in,
      or
      are defined by reference in, Article
      I below).






W
      I T
      N E S S E T H :




WHEREAS,
      the Account Party, the Lenders and The Bank of Nova Scotia, as the Issuer and
      as
      Administrative Agent, are all parties to the Reimbursement Agreement, dated
      as
      of March 31, 2005 (as amended or otherwise modified prior to the date hereof,
      the “ Existing
      Reimbursement Agreement ”,
      and as
      amended by this Amendment and as the same may be further amended, supplemented,
      amended and restated or otherwise modified from time to time, the “ Reimbursement
      Agreement ”);




WHEREAS,
      the Account Party has requested that the Lenders amend certain provisions of
      the
      Existing Reimbursement Agreement to permit Letters of Credit to be issued for
      additional account parties, on the terms and subject to the conditions
      hereinafter set forth;




NOW,
      THEREFORE, the parties hereto hereby covenant and agree as follows:




ARTICLE
      I


DEFINITIONS




SECTION
      1.1.  Certain
      Definitions .
      The
      following terms when used in this Amendment shall have the following meanings
      (such meanings to be equally applicable to the singular and plural forms
      thereof):




“ Account
      Party ”
is
      defined in the preamble .




“ Amendment ”
is
      defined in the preamble .




“ Amendment
      Effective Date ”
is
      defined in Article
      III .




“ Existing
      Reimbursement Agreement ”
is
      defined in the first
      recital .




“ Reimbursement
      Agreement ”
is
      defined in the first
      recital .






SECTION
      1.2.  Other
      Definitions .
      Terms
      for which meanings are provided in the Reimbursement Agreement are, unless
      otherwise defined herein or the context otherwise requires, used in this
      Amendment with such meanings.




ARTICLE
      II


AMENDMENTS
      TO REIMBURSEMENT AGREEMENT




Effective
      as of the date hereof, but subject to the occurrence of the satisfaction of
      the
      conditions in Article
      III ,
      the
      provisions of the Existing Reimbursement Agreement referred to below are hereby
      amended in accordance with this Article
      II .
      Except
      as expressly so amended, the Existing Reimbursement Agreement shall continue
      in
      full force and effect in accordance with its terms.




SECTION
      2.1.  Amendments
      to Section 1.1 .
      Section
      1.1 of the Existing Reimbursement Agreement is hereby amended by inserting
      the
      following definitions in the appropriate alphabetical order:




“ Additional
      Account Parties ”
is
      defined in Section
      2.1 .




“ Fourth
      Amendment ”
means
      the Fourth Amendment to Reimbursement Agreement, dated as of April 12, 2006,
      among the Account Party and the Lenders party thereto.




SECTION
      2.2.  Amendment
      to Article II .
      Section
      2.1 of
      the
      Existing Reimbursement Agreement is
      hereby
      amended by inserting the following at the end of such Section.




The
      Account Party shall be permitted to request that the Issuer issue Letters of
      Credit listing any of the following Persons (in addition to the Account Party)
      as the account party on such Letter of Credit: Avon Lake Synfuels, LLC, BG
      Mechanicals, Inc., General Control Systems, Inc, McCarl’s Inc., Penn Mines, LLC,
      PPL Brunner Island, LLC, PPL Corporation, PPL Distributed Generation, LLC,
      PPL
      Energy Supply, LLC, PPL EnergyPlus, LLC, PPL Energy Services Northeast, Inc.,
      PPL Energy Services Holdings, LLC, PPL Gas Utilities Corporation, PPL
      Generation, LLC, PPL Holtwood, LLC, PPL Martin Creeks, LLC, PPL Montana, LLC,
      PPL Sundance Energy, LLC, PPL Susquehanna, LLC, PPL Wallingford Energy, LLC
      or
      Tyrone Synfuels, L.P (collectively, the “ Additional
      Account Parties ”). Notwithstanding
      that a Letter of Credit issued or outstanding hereunder is in support of any
      obligations of, or is for the account of, an Additional Account Party, the
      Account Party shall be obligated to reimburse the Issuer for any and all
      drawings under such Letter of Credit. The Account Party hereby acknowledges
      that
      the Issuer would be unwilling to issue Letters of Credit for the account of
      Additional Account Parties without the Account Party’s agreement to such
      reimbursement obligation, and that the Account Party derives benefits from
      the
      issuances of such Letters of Credit.





ARTICLE
      III


CONDITIONS
      TO EFFECTIVENESS




This
      Amendment and the amendments contained herein shall become effective as of
      the
      date hereof when each of the conditions set forth in this Article
      III shall
      have been fulfilled to the satisfaction of the Administrative
      Agent.




SECTION
      3.1.  Counterparts .
      The
      Administrative Agent shall have received counterparts hereof executed on behalf
      of the Account Party and the Required Lenders.




SECTION
      3.2.  Costs
      and Expenses, etc .
      The
      Administrative Agent shall have received for the account of each Lender, all
      fees, costs and expenses due and payable pursuant to Section 10.3 of the
      Reimbursement Agreement, if then invoiced.




SECTION
      3.3.  Satisfactory
      Legal Form .
      The
      Administrative Agent and its counsel shall have received all information, and
      such counterpart originals or such certified or other copies of such materials,
      as the Administrative Agent or its counsel may reasonably request, and all
      legal
      matters incident to the effectiveness of this Amendment shall be satisfactory
      to
      the Administrative Agent and its counsel. All documents executed or submitted
      pursuant hereto or in connection herewith shall be reasonably satisfactory
      in
      form and substance to the Administrative Agent and its counsel.




ARTICLE
      IV


MISCELLANEOUS




SECTION
      4.1.  Cross-References .
      References in this Amendment to any Article or Section are, unless otherwise
      specified, to such Article or Section of this Amendment.




SECTION
      4.2.  Loan
      Document Pursuant to Existing Reimbursement Agreement .
      This
      Amendment is a Loan Document executed pursuant to the Existing Reimbursement
      Agreement and shall (unless otherwise expressly indicated therein) be construed,
      administered and applied in accordance with all of the terms and provisions
      of
      the Existing Reimbursement Agreement, as amended hereby, including
      Article X thereof.




SECTION
      4.3.  Successors
      and Assigns .
      This
      Amendment shall be binding upon and inure to the benefit of the parties hereto
      and their respective successors and assigns.




SECTION
      4.4.  Counterparts .
      This
      Amendment may be executed by the parties hereto in several counterparts, each
      of
      which when executed and delivered shall be an original and all of which shall
      constitute together but one and the same agreement. Delivery of an executed
      counterpart of a signature page to this Amendment by facsimile shall be
      effective as delivery of a manually executed counterpart of this
      Amendment.




SECTION
      4.5.  Governing
      Law .
      THIS
      AMENDMENT WILL BE DEEMED TO BE A CONTRACT MADE UNDER AND GOVERNED BY THE
      INTERNAL LAWS OF THE STATE OF NEW YORK (INCLUDING FOR SUCH PURPOSE SECTIONS
      5-1401 AND 5-1402 OF THE GENERAL OBLIGATIONS LAW OF THE STATE OF NEW
      YORK).




SECTION
      4.6.  Full
      Force and Effect; Limited Amendment .
      Except as expressly amended hereby, all of the representations, warranties,
      terms, covenants, conditions and other provisions of the Existing Reimbursement
      Agreement and the Loan Documents shall remain unchanged and shall continue
      to
      be, and shall remain, in full force and effect in accordance with their
      respective terms. The amendments set forth herein shall be limited precisely
      as
      provided for herein to the provisions expressly amended herein and shall not
      be
      deemed to be an amendment to, waiver of, consent to or modification of any
      other
      term or provision of the Existing Reimbursement Agreement or any other Loan
      Document or of any transaction or further or future action on the part of any
      Obligor which would require the consent of the Lenders under the Existing
      Reimbursement Agreement or any of the Loan Documents.




SECTION
      4.7.  Representations
      and Warranties .
      In
      order to induce the Lenders to execute and deliver this Amendment, the Account
      Party hereby represents and warrants to the Lenders, on the date this Amendment
      becomes effective pursuant to Article
      III ,
      that
      both before and after giving effect to this Amendment, all statements set forth
      in Section 5.2.1 of the Reimbursement Agreement are true and correct as of
      such
      date, except to the extent that any such statement expressly relates to an
      earlier date (in which case such statement was true and correct on and as of
      such earlier date).












IN
      WITNESS WHEREOF, the parties hereto have executed and delivered this Amendment
      as of the date first above written.









PPL
      ENERGY SUPPLY, LLC








By:__________________________


Title:





THE
      BANK
      OF NOVA SCOTIA








By:__________________________


Title: