TWENTY-SECOND SUPPLEMENTAL INDENTURE

Exhibit 4.1

NRG ENERGY, INC.,

as Issuer

8.50% SENIOR NOTES DUE 2019

TWENTY-SECOND SUPPLEMENTAL INDENTURE

Dated as of June 5, 2009

To

INDENTURE

Dated as of February 2, 2006

The Law Debenture Trust Company of New York

as Trustee

CROSS-REFERENCE TABLE*

TABLE OF CONTENTS

EXHIBITS

     TWENTY-SECOND SUPPLEMENTAL INDENTURE, dated as of June 5, 2009, by and among NRG Energy, Inc., a Delaware corporation (the “ Company ”), the Guarantors (as defined herein) and Law Debenture Trust Company of New York, as trustee (the “ Trustee ”).

     The Company has heretofore executed and delivered to the Trustee an Indenture, dated as of February 2, 2006 (the “ Base Indenture ”) providing for the issuance from time to time of one or more series of the Company’s securities.

     The Company and the Guarantors desire and have requested the Trustee pursuant to Section 9.1 of the Base Indenture to join with them in the execution and delivery of this Supplemental Indenture in order to supplement the Base Indenture as and to the extent set forth herein to provide for the issuance and the terms of the Notes (as defined below).

     Section 9.1 of the Base Indenture provides that the Company and the Trustee, without the consent of any holders of the Company’s Securities, may amend or waive certain terms and covenants in the Indenture as permitted by Sections 2.1 and 2.2 of the Base Indenture.

     The execution and delivery of this Supplemental Indenture has been duly authorized by a Board Resolution of the Company and each of the Guarantors.

     All conditions and requirements necessary to make this Supplemental Indenture a valid, binding and legal instrument in accordance with its terms have been performed and fulfilled by the parties hereto and the execution and delivery thereof have been in all respects duly authorized by the parties hereto.

     The Company, the Guarantors and the Trustee agree as follows for the benefit of each other and for the equal and ratable benefit of the Holders (as defined herein) of the 8.50% Senior Notes due 2019 (the “ Notes ”):

ARTICLE 1.
DEFINITIONS AND INCORPORATION
BY REFERENCE

          Section 1.01 Definitions.

     For all purposes of the Supplemental Indenture, the following terms shall have the respective meanings set forth in this Section.

     “ Acquired Debt ” means, with respect to any specified Person:

     (1) Indebtedness of any other Person or asset existing at the time such other Person or asset is merged with or into, is acquired by, or became a Subsidiary of such specified Person, as the case may be, whether or not such Indebtedness is incurred in connection with, or in contemplation of, such other Person merging with or into, or becoming a Restricted Subsidiary of, such specified Person; and

     (2) Indebtedness secured by a Lien encumbering any asset acquired by such specified Person.

     “ Additional Notes ” means additional notes (other than the Initial Notes) issued from time to time under this Supplemental Indenture in accordance with Section 2.05 hereof, as part of the same series as the Initial Notes

     “ Affiliate ” of any specified Person means any other Person directly or indirectly controlling or controlled by or under direct or indirect common control with such specified Person. For purposes of this definition, “control,” as used with respect to any Person, means the possession, directly or indirectly, of the power to direct or cause the direction of the management or policies of such Person, whether through the ownership of voting securities, by agreement or otherwise; provided that beneficial ownership of 10% or more of the Voting Stock of a Person will be deemed to be control. For purposes of this definition, the terms “controlling,” “controlled by” and “under common control with” have correlative meanings.

      “Agent” means any Registrar, co-registrar, Paying Agent or additional paying agent.

     “ Applicable Law ” shall mean, as to any Person, any ordinance, law, treaty, rule or regulation or determination by an arbitrator or a court or other Governmental Authority, including ERCOT, in each case, applicable to or binding on such Person or any of its property or assets or to which such Person or any of its property is subject.

     “ Applicable Premium ” means, with respect to any note on any redemption date, the greater of:

     (1) 1.0% of the principal amount of the note; or

     (2) the excess of:

     (a) the present value at such redemption date of (i) the redemption price of the Note at January 15, 2012, (such redemption price being set forth in the table appearing under Section 3.07 hereof) plus (ii) all required interest payments due on the Note through January 15, 2012 (excluding accrued but unpaid interest to the redemption date), computed using a discount rate equal to the Treasury Rate as of such redemption date plus 50 basis points; over

     (b) the principal amount of the Note, if greater.

     “ Applicable Procedures ” means, with respect to any transfer or exchange of or for beneficial interests in any Global Note, the rules and procedures of the Depositary that apply to such transfer or exchange.

     “ Asset Sale ” means:

     (1) the sale, lease (other than an Operating Lease), conveyance or other disposition of any assets or rights; provided that the sale, conveyance or other disposition of all or substantially all of the assets of the Company and its Restricted Subsidiaries taken as a whole will be governed by the provisions of this Supplemental Indenture described under Sections 4.14 and 5.01 hereof and not by the provisions of Section 4.10 hereof; and

     (2) the issuance of Equity Interests in any of the Company’s Restricted Subsidiaries or the sale of Equity Interests in any of its Subsidiaries.

     Notwithstanding the preceding, none of the following items will be deemed to be an Asset Sale:

     (1) any single transaction or series of related transactions for which the Company or its Restricted Subsidiaries receive aggregate consideration of less than $100.0 million;

     (2) a transfer of assets or Equity Interests between or among the Company and its Restricted Subsidiaries;

     (3) an issuance of Equity Interests by a Restricted Subsidiary of the Company to the Company or to a Restricted Subsidiary of the Company;

     (4) the sale or lease of products or services and any sale or other disposition of damaged, worn-out or obsolete assets;

     (5) the sale or discount, in each case without recourse, of accounts receivable, but only in connection with the compromise or collection thereof;

     (6) the licensing of intellectual property;

     (7) the sale, lease, conveyance or other disposition for value of energy, fuel or emission credits or contracts for any of the foregoing;

     (8) the sale or other disposition of cash or Cash Equivalents;

     (9) a Restricted Payment that does not violate Section 4.07 hereof or a Permitted Investment;

     (10) to the extent allowable under Section 1031 of the Internal Revenue Code of 1986, any exchange of like property (excluding any “boot” thereon) for use in a Permitted Business;

     (11) a disposition of assets in connection with a foreclosure, transfer or deed in lieu of foreclosure or other exercise of remedial action; and

     (12) any sale and leaseback transaction that is a Permitted Tax Lease.

     “ Asset Sale Offer ” has the meaning assigned to that term in this Supplemental Indenture.

     “ Attributable Debt ” in respect of a sale and leaseback transaction means, at the time of determination, the present value of the obligation of the lessee for net rental payments during the remaining term of the lease included in such sale and leaseback transaction including any period for which such lease has been extended or may, at the option of the lessor, be extended. Such present value shall be calculated using a discount rate equal to the rate of interest implicit in such transaction, determined in accordance with GAAP; provided , however , that if such sale and leaseback transaction results in a Capital Lease Obligation, the amount of Indebtedness represented thereby will be determined in accordance with the definition of “Capital Lease Obligation.”

      “Bankruptcy Law” means Title 11, U.S. Code or any similar federal or state law for the relief of debtors.

     “ Base Indenture ” means has the meaning set forth in the preamble to this Supplemental Indenture, as amended, supplemented or otherwise modified from time to time in accordance with the terms thereof.

     “ Beneficial Owner ” has the meaning assigned to such term in Rule 13d-3 and Rule 13d-5 under the Exchange Act. The terms “Beneficially Owns” and “Beneficially Owned” have a corresponding meaning.

     “ Board of Directors ” means:

     (1) with respect to a corporation, the board of directors of the corporation or any committee thereof duly authorized to act on behalf of such board;

     (2) with respect to a partnership, the board of directors of the general partner of the partnership;

     (3) with respect to a limited liability company, the managing member or members or any controlling committee of managing members thereof; and

     (4) with respect to any other Person, the board or committee of such Person serving a similar function.

      “Business Day” means any day other than a Legal Holiday.

     “ Capital Lease Obligation ” means, at the time any determination is to be made, the amount of the liability in respect of a capital lease that would at that time be required to be capitalized on a balance sheet in accordance with GAAP, and the Stated Maturity thereof shall be the date of the last payment of rent or any other amount due under such lease prior to the first date upon which such lease may be prepaid by the lessee without payment of a penalty.

     “ Capital Stock ” means:

     (1) in the case of a corporation, corporate stock;

     (2) in the case of an association or business entity, any and all shares, interests, participations, rights or other equivalents (however designated) of corporate stock;

     (3) in the case of a partnership or limited liability company, partnership interests (whether general or limited) or membership interests; and

     (4) any other interest or participation that confers on a Person the right to receive a share of the profits and losses of, or distributions of assets of, the issuing Person, but excluding from all of the foregoing any debt securities convertible into Capital Stock, whether or not such debt securities include any right of participation with Capital Stock.

     “ Cash Equivalents ” means:

     (1) United States dollars, Euros or, in the case of any Foreign Subsidiary, any local currencies held by it from time to time;

     (2) securities issued or directly and fully guaranteed or insured by the United States government or any agency or instrumentality of the United States government ( provided that the full faith and credit of the United States is pledged in support of those securities) having maturities of not more than twelve months from the date of acquisition;

     (3) certificates of deposit and eurodollar time deposits with maturities of twelve months or less from the date of acquisition, bankers’ acceptances with maturities not exceeding 12 months and overnight bank deposits, in each case, with any domestic commercial bank having capital and surplus in excess of $500.0 million and a Thomson Bank Watch Rating of “B” or better;

     (4) repurchase obligations with a term of not more than seven days for underlying securities of the types described in clauses (2) and (3) above entered into with any financial institution meeting the qualifications specified in clause (3) above;

     (5) commercial paper and auction rate securities having one of the two highest ratings obtainable from Moody’s or S&P and in each case maturing within 12 months after the date of acquisition;

     (6) readily marketable direct obligations issued by any state of the United States or any political subdivision thereof, in either case having one of the two highest rating categories obtainable from either Moody’s or S&P; and

     (7) money market funds that invest primarily in securities described in clauses (1) through (6) of this definition.

     “ Change of Control ” means the occurrence of any of the following:

     (1) the direct or indirect sale, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets of the Company and its Subsidiaries taken as a whole to any “person” (as that term is used in Section 13(d) of the Exchange Act, but excluding any employee benefit plan of the Company or any of its Restricted Subsidiaries, and any Person or entity acting in its capacity as trustee, agent or other fiduciary or administrator of such plan);

     (2) the adoption of a plan relating to the liquidation or dissolution of the Company;

     (3) the consummation of any transaction (including, without limitation, any merger or consolidation) the result of which is that any “person” (as defined above), other than a corporation owned directly or indirectly by the stockholders of the Company in substantially the same proportion as their ownership of stock of the Company prior to such transaction, becomes the Beneficial Owner, directly or indirectly, of more than 50% of the Voting Stock of the Company, measured by voting power rather than number of shares; or

     (4) the first day on which a majority of the members of the Board of Directors of the Company are not Continuing Directors.

     “ Change of Control Offer ” has the meaning assigned to it in this Supplemental Indenture.

     “ Change of Control Triggering Event ” means (i) a Change of Control has occurred and (ii) the Notes are downgraded by either S&P or Moody’s on any date during the period commencing 60 days prior to the consummation of such Change of Control and ending 60 days following consummation of such Change of Control.

     “ Company” means NRG Energy, Inc., and any and all successors thereto.

     “ Concurrent Cash Distributions ” has the meaning assigned to it in the definition of “Investments.”

     “ Consolidated Cash Flow ” means, with respect to any specified Person for any period, the Consolidated Net Income of such Person for such period plus, without duplication:

     (1) an amount equal to any extraordinary loss (including any loss on the extinguishment or conversion of Indebtedness) plus any net loss realized by such Person or any of its Restricted Subsidiaries in connection with an Asset Sale (without giving effect of the threshold provided in the definition thereof), to the extent such losses were deducted in computing such Consolidated Net Income; plus

     (2) provision for taxes based on income or profits of such Person and its Restricted Subsidiaries for such period, to the extent that such provision for taxes was deducted in computing such Consolidated Net Income; plus

     (3) the Fixed Charges of such Person and its Restricted Subsidiaries for such period, to the extent that such Fixed Charges were deducted in computing such Consolidated Net Income; plus

     (4) any expenses or charges related to any Equity Offering, Permitted Investment, acquisition, disposition, recapitalization or Indebtedness permitted to be incurred by the indenture including a refinancing thereof (whether or not successful), including such fees, expenses or charges related to the offering of the Notes and the Credit Agreement, and deducted in computing Consolidated Net Income; plus

     (5) any professional and underwriting fees related to any equity offering, Permitted Investment, acquisition, recapitalization or Indebtedness permitted to be incurred under this Supplemental Indenture and, in each case, deducted in such period in computing Consolidated Net Income; plus

     (6) the amount of any minority interest expense deducted in calculating Consolidated Net Income (less the amount of any cash dividends paid to the holders of such minority interests); plus

     (7) any non cash gain or loss attributable to Mark to Market Adjustments in connection with Hedging Obligations; plus

     (8) without duplication, any writeoffs, writedowns or other non-cash charges reducing Consolidated Net Income for such period, excluding any such charge that represents an accrual or reserve for a cash expenditure for a future period, plus

     (9) all items classified as extraordinary, unusual or nonrecurring non-cash losses or charges (including, without limitation, severance, relocation and other restructuring costs), and related tax effects according to GAAP to the extent such non-cash charges or losses were deducted in computing such Consolidated Net Income; plus

     (10) depreciation, depletion, amortization (including amortization of intangibles but excluding amortization of prepaid cash expenses that were paid in a prior period) and other non-cash charges and expenses (excluding any such non-cash expense to the extent that it represents an accrual of or reserve for cash expenses in any future period or amortization of a

prepaid cash expense that was paid in a prior period) of such Person and its Restricted Subsidiaries for such period to the extent that such depreciation, depletion, amortization and other non-cash expenses were deducted in computing such Consolidated Net Income; minus

     (11) non-cash items increasing such Consolidated Net Income for such period, other than the accrual of revenue in the ordinary course of business; in each case, on a consolidated basis and determined in accordance with GAAP (including, without limitation, any increase in amortization or depreciation or other non-cash charges resulting from the application of purchase accounting in relation to any acquisition that is consummated after the Issue Date); minus

     (12) interest income for such period;

provided , however , that Consolidated Cash Flow of the Company will exclude the Consolidated Cash Flow attributable to (i) Excluded Subsidiaries to the extent that the declaration or payment of dividends or similar distributions by the Excluded Subsidiary of that Consolidated Cash Flow is not, as a result of an Excluded Subsidiary Debt Default, then permitted by operation of the terms of the relevant Excluded Subsidiary Debt Agreement ( provided that the Consolidated Cash Flow of the Excluded Subsidiary will only be so excluded for that portion of the period during which the condition described in the preceding proviso has occurred and is continuing), and (ii) for purposes of Section 4.07 hereof only, Excluded Project Subsidiaries, except to the extent of any dividends or similar distributions paid in cash to the Company or a Restricted Subsidiary of the Company that is not an Excluded Project Subsidiary.

     “ Consolidated Interest Expense ” means, with respect to any Person for any period, the consolidated cash interest expense of such Person and its Restricted Subsidiaries (other than Excluded Project Subsidiaries) for such period, whether paid or accrued (including, without limitation, the interest component of any deferred payment obligations, the interest component of all payments associated with Capital Lease Obligations, imputed interest with respect to Attributable Debt, commissions, discounts and other fees and charges incurred in respect of letter of credit or bankers’ acceptance financings, and net payments (if any) pursuant to interest rate Hedging Obligations, but not including amortization of original issue discount and other non-cash interest payments), net of cash interest income. For purposes of the foregoing, interest expense shall be determined after giving effect to any net payments made or received by the Company or any Restricted Subsidiary (other than an Excluded Project Subsidiary) with respect to any interest rate hedging agreements.

     “ Consolidated Net Income ” means, with respect to any specified Person for any period, the aggregate of the Net Income of such Person and its Restricted Subsidiaries for such period, on a consolidated basis, determined in accordance with GAAP; provided that:

     (1) the Net Income of any Person that is not a Restricted Subsidiary or that is accounted for by the equity method of accounting will be included only to the extent of the amount of dividends or similar distributions (including pursuant to other intercompany payments but excluding Concurrent Cash Distributions) paid in cash to the specified Person or a Restricted Subsidiary of the Person;

     (2) for purposes of Section 4.07 hereof only, the Net Income of any Restricted Subsidiary will be excluded to the extent that the declaration or payment of dividends or similar distributions by that Restricted Subsidiary of that Net Income is not at the date of determination permitted without any prior governmental approval (that has not been obtained) or, directly or indirectly, by operation of the terms of its charter or any agreement, instrument,

judgment, decree, order, statute, rule or governmental regulation applicable to that Restricted Subsidiary or its stockholders;

     (3) the cumulative effect of a change in accounting principles will be excluded;

     (4) any net after-tax non-recurring or unusual gains, losses (less all fees and expenses relating thereto) or other charges or revenue or expenses (including, without limitation, relating to severance, relocation and one-time compensation charges) shall be excluded;

     (5) any non-cash compensation expense recorded from grants of stock appreciation or similar rights, stock options, restricted stock or other rights to officers, directors or employees shall be excluded, whether under FASB 123R or otherwise;

     (6) any net after-tax income (loss) from disposed or discontinued operations and any net after-tax gains or losses on disposal of disposed or discontinued operations shall be excluded;

     (7) any gains or losses (less all fees and expenses relating thereto) attributable to asset dispositions shall be excluded; and

     (8) any impairment charge or asset write-off pursuant to Financial Accounting Statement No. 142 and No. 144 or any successor pronouncement shall be excluded.

     “ Continuing Director ” means, as of any date of determination, any member of the Board of Directors of the Company who:

     (1) was a member of such Board of Directors on the Issue Date; or

     (2) was nominated for election or elected to such Board of Directors with the approval of a majority of the Continuing Directors who were members of such Board at the time of such nomination or election.

     “ Contribution Indebtedness ” means Indebtedness of the Company in an aggregate principal amount not to exceed two times the aggregate amount of cash received by the Company after the Issue Date from the sale of its Equity Interests (other than Disqualified Stock) or as a contribution to its common equity capital (in each case, other than to or from a Subsidiary of the Company); provided that such Indebtedness (a) is incurred within 180 days after the sale of such Equity Interests or the making of such capital contribution and (b) is designated as “Contribution Indebtedness” pursuant to an Officers’ Certificate on the date of its incurrence. Any sale of Equity Interests or capital contribution that forms the basis for an incurrence of Contribution Indebtedness will not be considered to be a sale of Qualifying Equity Interests and will be disregarded for purposes of Section 4.07 hereof and will not be considered to be an Equity Offering for purposes of Section 3.07 hereof.

      “Corporate Trust Office of the Trustee” will be at the address of the Trustee specified in Section 12.02 hereof or such other address as to which the Trustee may give notice to the Company.

     “ Credit Agreement ” means the Second Amended and Restated Credit Agreement, dated June 8, 2007, among the Company, the lenders from time to time party thereto, Citigroup Global Markets Inc. and Credit Suisse Securities (USA) LLC, as joint book runners and joint lead arrangers, Citicorp North America, Inc., as administrative agent and collateral agent, and Credit Suisse, as syndication agent.

     “ Credit Facilities ” means (i) one or more debt facilities (including, without limitation, the Credit Agreement) or commercial paper facilities, in each case with banks or other institutional lenders providing for revolving credit loans, term loans, credit-linked deposits (or similar deposits) receivables financing (including through the sale of receivables to such lenders or to special purpose entities formed to borrow from such lenders against such receivables) or letters of credit and (ii) debt securities sold to institutional investors, in each case, as amended, restated, modified, renewed, refunded, replaced or refinanced (including by means of sales of debt securities to institutional investors) in whole or in part from time to time.

     “ Custodian ” means the Trustee, as custodian with respect to the Notes in global form, or any successor entity thereto.

     “ Debt to Cash Flow Ratio ” means, as of any date of determination (for purposes of this definition, the “ Calculation Date ”), the ratio of (a) the Total Debt of the Company as of such date to (b) the Consolidated Cash Flow of the Company for the four most recent full fiscal quarters ending immediately prior to such date for which financial statements are publicly available. For purposes of making the computation referred to above:

     (1) Investments and acquisitions that have been made by the Company or any of its Restricted Subsidiaries, including through mergers or consolidations, or any Person or any of its Restricted Subsidiaries acquired by the Company or any of its Restricted Subsidiaries, and including any related financing transactions and including increases in ownership of Restricted Subsidiaries, during the four-quarter reference period or subsequent to such reference period and on or prior to the Calculation Date will be given pro forma effect (in accordance with Regulation S-X under the Securities Act, but including all Pro Forma Cost Savings) as if they had occurred on the first day of the four-quarter reference period;

     (2) the Consolidated Cash Flow attributable to discontinued operations, as determined in accordance with GAAP, and operations or businesses (and ownership interests therein) disposed of prior to the Calculation Date, will be excluded;

     (3) any Person that is a Restricted Subsidiary on the Calculation Date will be deemed to have been a Restricted Subsidiary at all times during such four-quarter period;

     (4) any Person that is not a Restricted Subsidiary on the Calculation Date will be deemed not to have been a Restricted Subsidiary at any time during such four-quarter period; and

     (5) the Consolidated Cash Flow attributable to Excluded Project Subsidiaries will be excluded for purposes of all calculations required by this definition.

     “ Default ” means any event that is, or with the passage of time or the giving of notice or both would be, an Event of Default.

     “ Definitive Note ” means a certificated Note registered in the name of the Holder thereof and issued in accordance with Section 2.04 hereof, substantially in the form of Exhibit A hereto except that such Note shall not bear the Global Note Legend.

      “Description of Notes ” means the section titled “Description of the Notes” in the Prospectus Supplement, dated June 2, 2009, related to the issuance and sale of the Initial Notes.

     “ Designated Noncash Consideration ” means the fair market value of non-cash consideration received by the Company or any Person who is an Affiliate of the Company as a result of the Company’s ownership of Equity Interests in such Person in connection with an Asset Sale that is so designated as Designated Noncash Consideration pursuant to an Officers’ Certificate, setting forth the basis of such valuation, executed by a senior financial officer of the Company, less the amount of cash or Cash Equivalents received in connection with a subsequent sale of such Designated Noncash Consideration.

     “ Disqualified Stock ” means any Capital Stock that, by its terms (or by the terms of any security into which it is convertible, or for which it is exchangeable, in each case at the option of the holder of the Capital Stock), or upon the happening of any event, matures or is mandatorily redeemable, pursuant to a sinking fund obligation or otherwise, or redeemable at the option of the holder of the Capital Stock, in whole or in part, on or prior to the date that is 91 days after the date on which the Notes mature. Notwithstanding the preceding sentence, any Capital Stock that would constitute Disqualified Stock solely because the holders of the Capital Stock have the right to require the Company to repurchase such Capital Stock upon the occurrence of a change of control or an asset sale will not constitute Disqualified Stock if the terms of such Capital Stock provide that the Company may not repurchase or redeem any such Capital Stock pursuant to such provisions unless such repurchase or redemption complies with Section 4.07 hereof. The amount of Disqualified Stock deemed to be outstanding at any time for purposes of the indenture will be the maximum amount that the Company and its Restricted Subsidiaries may become obligated to pay upon the maturity of, or pursuant to any mandatory redemption provisions of, such Disqualified Stock, exclusive of accrued dividends.

     “ Domestic Subsidiary ” means any Restricted Subsidiary of the Company that was formed under the laws of the United States or any state of the United States or the District of Columbia or that guarantees or otherwise provides direct credit support for any Indebtedness of the Company.

     “ Environmental CapEx Debt ” shall mean Indebtedness of the Company or its Restricted Subsidiaries incurred for the purpose of financing Environmental Capital Expenditures.

     “ Environmental Capital Expenditures ” shall mean capital expenditures deemed necessary by the Company or its Restricted Subsidiaries to comply with Environmental Laws.

     “ Environmental Law ” shall mean any applicable Federal, state, foreign or local statute, law, rule, regulation, ordinance, code and rule of common law now or hereafter in effect and in each case as amended, and any binding judicial or administrative interpretation thereof, including any binding judicial or administrative order, consent decree or judgment, relating to the environment, human health or safety or Hazardous Materials.

     “ Equity Interests ” means Capital Stock and all warrants, options or other rights to acquire Capital Stock (but excluding any debt security that is convertible into, or exchangeable for, Capital Stock).

     “ Equity Offering ” means a sale of Capital Stock (other than Disqualified Stock) of the Company pursuant to (1) a public offering or (2) a private placement to Persons who are not Affiliates of the Company.

     “ ERCOT ” means the Electric Reliability Council of Texas.

      “Exchange Act” means the Securities Exchange Act of 1934, as amended.

     “ Excluded Foreign Subsidiary ” means, at any time, any Foreign Subsidiary that is (or is treated as) for United States federal income tax purposes either (1) a corporation or (2) a pass-through entity

owned directly or indirectly by another Foreign Subsidiary that is (or is treated as) a corporation; provided that notwithstanding the foregoing, the following entities will be deemed to be “Excluded Foreign Subsidiaries”: Sterling Luxembourg (No. 4) S.a.r.l., NRG Pacific Corporate Services Pty Ltd., Tosli Acquisition B.V. and any subsidiary of Tosli Acquisition B.V. incorporated or formed in connection with the Itiquira Refinancing.

     “ Excluded Proceeds ” means any Net Proceeds of an Asset Sale involving:

     (1) the sale of up to $300,000,000 in the aggregate received since the Issue Date from one or more Asset Sales of Equity Interests in, or property or assets of, any Foreign Subsidiaries or any Foreign Subsidiary Holding Company; and

     (2) the sale of up to $50,000,000 of assets per year, in either event if and to the extent such Net Proceeds are designated by a Responsible Officer of the Company as Excluded Proceeds.

     “ Excluded Project Subsidiary ” shall mean, at any time,

     (1) each Subsidiary of the Company that is an obligor or otherwise bound with respect to Non-Recourse Debt on the Issue Date,

     (2) any Person that becomes a Subsidiary of the Company after the Issue Date that is an obligor or otherwise bound with respect to Indebtedness that constitutes Non-Recourse Debt and that is not an obligor with respect to any other Indebtedness,

     (3) any Person that is a Subsidiary of the Company on the Issue Date or any Person that becomes a Subsidiary of the Company after the Issue Date and that, in each case, has been designated, by a certificate executed by a Responsible Officer of the Company, as an Excluded Project Subsidiary dedicated to constructing or acquiring power generation facilities or related or ancillary assets or properties that are to be financed only with equity contributions and Non-Recourse Debt (and not any other Indebtedness), and

     (4) any Subsidiary of the Company that (i) has been released as a Guarantor under this Supplemental Indenture pursuant to Section 10.05(a)(7) hereof or (ii), in the case of newly acquired or formed Subsidiaries, is not otherwise required to execute a Guarantee pursuant to Section 4.17 hereof.

     “ Excluded Subsidiaries ” means the Excluded Project Subsidiaries, the Excluded Foreign Subsidiaries and the Immaterial Subsidiaries.

     “ Excluded Subsidiary Debt Agreement ” means the agreement or documents governing the relevant Indebtedness referred to in the definition of “Excluded Subsidiary Debt Default.”

     “ Excluded Subsidiary Debt Default ” means, with respect to any Excluded Subsidiary, the failure of such Excluded Subsidiary to pay any principal or interest or other amounts due in respect of any Indebtedness, when and as the same shall become due and payable, or the occurrence of any other event or condition that results in any Indebtedness of such Excluded Subsidiary becoming due prior to its scheduled maturity or that enables or permits (with or without the giving of notice, lapse of time or both) the holder or holders of such Indebtedness or any trustee or agent on its or their behalf to cause such Indebtedness to become due, or to require the prepayment, repurchase, redemption or defeasance thereof, prior to its scheduled maturity.

     “ Exempt Subsidiaries ” means, collectively, NRG Ilion LP LLC, NRG Ilion Limited Partnership, Meriden Gas Turbine LLC, LSP-Nelson Energy LLC, NRG Nelson Turbines LLC, NRG Jackson Valley Energy I, Inc., NRG McClain LLC, NRG Audrain Holding LLC, NRG Audrain Generating LLC, NRG Peaker Finance Company LLC, Bayou Cove Peaking Power, LLC, Big Cajun I Peaking Power LLC, NRG Rockford LLC, NRG Rockford II LLC, NRG Rockford Equipment II LLC, NRG Sterlington Power LLC and NRG Rockford Acquisition LLC.

     “ Existing Indebtedness ” means Indebtedness of the Company and its Subsidiaries (other than Indebtedness under the Credit Agreement and the Existing Genco Credit Facility and Notes Indebtedness) in existence on the Issue Date, until such amounts are repaid.

      “Existing Indentures” means the indentures governing the Existing Senior Notes.

      “Existing Senior Notes” means all notes issued pursuant to the indentures governing NRG’s outstanding 7.250% Senior Notes due 2014, 7.375% Senior Notes due 2016 and 7.375% Senior Notes due 2017.

     “ Facility ” means a power or energy related facility.

     “ fair market value ” means the value that would be paid by a willing buyer to an unaffiliated willing seller in a transaction not involving distress or necessity of either party, determined in good faith by a Responsible Officer of the Company.

     “ Fixed Charge Coverage Ratio ” means with respect to any specified Person for any period, the ratio of the Consolidated Cash Flow of such Person for such period to the Fixed Charges of such Person for such period. In the event that the specified Person or any of its Restricted Subsidiaries incurs, assumes, Guarantees, repays, repurchases, redeems, defeases or otherwise discharges any Indebtedness (other than ordinary working capital borrowings) or issues, repurchases or redeems preferred stock subsequent to the commencement of the period for which the Fixed Charge Coverage Ratio is being calculated and on or prior to the date on which the event for which the calculation of the Fixed Charge Coverage Ratio is made (for the purposes of this definition, the “ Calculation Date ”), then the Fixed Charge Coverage Ratio will be calculated giving pro forma effect to such incurrence, assumption, Guarantee, repayment, repurchase, redemption, defeasance or other discharge of Indebtedness, or such issuance, repurchase or redemption of preferred stock, and the use of the proceeds therefrom, as if the same had occurred at the beginning of the applicable four-quarter reference period.

     In addition, for purposes of calculating the Fixed Charge Coverage Ratio:

     (1) Investments and acquisitions that have been made by the specified Person or any of its Restricted Subsidiaries, including through mergers or consolidations, or any Person or any of its Restricted Subsidiaries acquired by the specified Person or any of its Restricted Subsidiaries, and including any related financing transactions and including increases in ownership of Restricted Subsidiaries, during the four-quarter reference period or subsequent to such reference period and on or prior to the Calculation Date will be given pro forma effect (in accordance with Regulation S-X under the Securities Act, but including all Pro Forma Cost Savings) as if they had occurred on the first day of the four-quarter reference period and Consolidated Cash Flow for such reference period will be calculated on the same pro forma basis;

     (2) the Consolidated Cash Flow attributable to discontinued operations, as determined in accordance with GAAP, and operations or businesses (and ownership interests therein) disposed of prior to the Calculation Date, will be excluded;

     (3) the Fixed Charges attributable to discontinued operations, as determined in accordance with GAAP, and operations or businesses (and ownership interests therein) disposed of prior to the Calculation Date, will be excluded, but only to the extent that the obligations giving rise to such Fixed Charges will not be obligations of the specified Person or any of its Restricted Subsidiaries following the Calculation Date;

     (4) any Person that is a Restricted Subsidiary on the Calculation Date will be deemed to have been a Restricted Subsidiary at all times during such four-quarter period;

     (5) any Person that is not a Restricted Subsidiary on the Calculation Date will be deemed not to have been a Restricted Subsidiary at any time during such four-quarter period; and

     (6) if any Indebtedness that is being incurred on the Calculation Date bears a floating rate of interest, the interest expense on such Indebtedness will be calculated as if the rate in effect on the Calculation Date had been the applicable rate for the entire period (taking into account any Hedging Obligation applicable to such Indebtedness).

     If since the beginning of such period any Person (that subsequently became a Restricted Subsidiary or was merged with or into the Company or any Restricted Subsidiary since the beginning of such period) shall have made any Investment, acquisition, disposition, merger, consolidation or disposed operation that would have required adjustment pursuant to this definition, then the Fixed Charge Coverage Ratio shall be calculated giving pro forma effect thereto (including any Pro Forma Cost Savings) for such period as if such Investment, acquisition or disposition, or classification of such operation as discontinued had occurred at the beginning of the applicable four-quarter period.

     “ Fixed Charges ” means, with respect to any specified Person for any period, the sum, without duplication, of:

     (1) the consolidated interest expense of such Person and its Restricted Subsidiaries (other than interest expense of any Excluded Subsidiary the Consolidated Cash Flow of which is excluded from the Consolidated Cash Flow of such Person pursuant to the definition of Consolidated Cash Flow hereof) for such period, whether paid or accrued, including, without limitation, amortization of debt issuance costs and original issue discount, non-cash interest payments, the interest component of any deferred payment obligations, the interest component of all payments associated with Capital Lease Obligations, imputed interest with respect to Attributable Debt, and net of the effect of all payments made or received pursuant to Hedging Obligations in respect of interest rates; plus

     (2) the consolidated interest of such Person and its Restricted Subsidiaries that was capitalized during such period; plus

     (3) any interest accruing on Indebtedness of another Person that is Guaranteed by such Person or one of its Restricted Subsidiaries or secured by a Lien on assets of such Person or one of its Restricted Subsidiaries, whether or not such Guarantee or Lien is called upon; plus

     (4) the product of (a) all dividends, whether paid or accrued and whether or not in cash, on any series of preferred stock of such Person or any of its Restricted Subsidiaries, other than dividends on Equity Interests payable in Equity Interests of the Company (other than Disqualified Stock) or to the Company or a Restricted Subsidiary of the Company, times (b) a

fraction, the numerator of which is one and the denominator of which is one minus the then current combined federal, state and local statutory tax rate of such Person, expressed as a decimal, in each case, on a consolidated basis and in accordance with GAAP; minus

     (5) interest income for such period.

     “ Foreign Subsidiary ” means any Restricted Subsidiary that is not a Domestic Subsidiary.

     “ Foreign Subsidiary Holding Company ” means any Domestic Subsidiary that is a direct parent of one or more Foreign Subsidiaries and holds, directly or indirectly, no other assets other than Equity Interests of Foreign Subsidiaries and other de minimis assets related thereto.

     “ GAAP ” means generally accepted accounting principles set forth in the opinions and pronouncements of the Accounting Principles Board of the American Institute of Certified Public Accountants and statements and pronouncements of the Financial Accounting Standards Board or in such other statements by such other entity as have been approved by a significant segment of the accounting profession, which are in effect from time to time.

     “ Global Note Legend ” means the legend set forth in Section 2.04(f), which is required to be placed on all Global Notes issued under this Supplemental Indenture.

     “ Global Notes ” means, individually and collectively, each of the Global Notes substantially in the form of Exhibit A hereto issued in accordance with Section 2.01 hereof.

     “ Goldman Sachs Hedge Agreement ” means the Master Power Purchase and Sale Agreement dated as of July 21, 2004, between an affiliate of Goldman, Sachs & Co. and Texas Genco, LP, as amended to the Issue Date, and any agreements related thereto.

     “ Government Securities ” means direct obligations of, or obligations guaranteed by, the United States of America (including any agency or instrumentality thereof) for the payment of which obligations or guarantees the full faith and credit of the United States of America is pledged and which are not callable or redeemable at the issuer’s option.

     “ Governmental Authority ” shall mean any nation or government, any state, province, territory or other political subdivision thereof, and any entity exercising executive, legislative, judicial, regulatory or administrative functions of or pertaining to government, or any non-governmental authority regulating the generation and/or transmission of energy.

     “ Guarantee ” means a guarantee other than by endorsement of negotiable instruments for collection in the ordinary course of business, direct or indirect, in any manner including, without limitation, by way of a pledge of assets or through letters of credit or reimbursement agreements in respect thereof, of all or any part of any Indebtedness (whether arising by virtue of partnership arrangements, or by agreements to keep-well, to purchase assets, goods, securities or services, to take or pay or to maintain financial statement conditions or otherwise).

     “ Guarantors ” means each of:

     (1) the Company’s Restricted Subsidiaries other than the Excluded Foreign Subsidiaries, the Excluded Project Subsidiaries, and the Immaterial Subsidiaries; and

     (2) any other Restricted Subsidiary that executes a Subsidiary Guarantee in accordance with the provisions of this Supplemental Indenture;

and their respective successors and assigns.

     “ Hazardous Materials ” shall mean (a) any petroleum or petroleum products, radioactive materials, friable asbestos, urea formaldehyde foam insulation, transformers or other equipment that contain dielectric fluid containing regulated levels of polychlorinated biphenyls and radon gas; (b) any chemicals, materials or substances defined as or included in the definition of “hazardous substances,” “hazardous waste,” “hazardous materials,” “extremely hazardous waste,” “restricted hazardous waste,” “toxic substances,” “toxic pollutants,” “contaminants,” or “pollutants” or words of similar import, under any applicable Environmental Law; and (c) any other chemical, material or substance, which is prohibited, limited or regulated by any Environmental Law.

     “ Hedging Obligations ” means, with respect to any specified Person, the obligations of such Person under:

     (1) currency exchange, interest rate or commodity swap agreements, currency exchange, interest rate or commodity cap agreements and currency exchange, interest rate or commodity collar agreements, and

     (2) (i) agreements or arrangements designed to protect such Person against fluctuations in currency exchange, interest rates, commodity prices or commodity transportation or transmission pricing or availability, including but not limited to the Goldman Sachs Hedge Agreement; (ii) any netting arrangements, power purchase and sale agreements, fuel purchase and sale agreements, swaps, options and other agreements, in each case, that fluctuate in value with fluctuations in energy, power or gas prices; and (iii) agreements or arrangements for commercial or trading activities with respect to the purchase, transmission, distribution, sale, lease or hedge of any energy related commodity or service.

     “ Holder ” means a Person in whose name a Note is registered.

     “ Immaterial Subsidiary ” shall mean, at any time, any Restricted Subsidiary of the Company that is designated by the Company as an “Immaterial Subsidiary” if and for so long as such Restricted Subsidiary, together with all other Immaterial Subsidiaries, has (i) total assets at such time not exceeding 5% of the Company’s consolidated assets as of the most recent fiscal quarter for which balance sheet information is available and (ii) total revenues and operating income for the most recent 12-month period for which income statement information is available not exceeding 5% of the Company’s consolidated revenues and operating income, respectively; provided that such Restricted Subsidiary shall be an Immaterial Subsidiary only to the extent that and for so long as all of the above requirements are satisfied.

     “ Indebtedness ” means, with respect to any specified Person, any indebtedness of such Person (excluding accrued expenses and trade payables, except as provided in clause (5) below), whether or not contingent:

     (1) in respect of borrowed money;

     (2) evidenced by bonds, notes, debentures or similar instruments or letters of credit (or reimbursement agreements in respect thereof);

     (3) in respect of banker’s acceptances;

     (4) representing Capital Lease Obligations or Attributable Debt in respect of sale and leaseback transactions;

     (5) representing the balance deferred and unpaid of the purchase price of any property (including trade payables) or services due more than six months after such property is acquired or such services are completed; or

     (6) representing the net amount owing under any Hedging Obligations,

if and to the extent any of the preceding items (other than letters of credit, Attributable Debt and Hedging Obligations) would appear as a liability upon a balance sheet of the specified Person prepared in accordance with GAAP. In addition, the term “Indebtedness” includes all Indebtedness of others secured by a Lien on any asset of the specified Person (whether or not such Indebtedness is assumed by the specified Person) and, to the extent not otherwise included, the Guarantee by the specified Person of any Indebtedness of any other Person; provided , that the amount of such Indebtedness shall be deemed not to exceed the lesser of the amount secured by such Lien and the value of the Person’s property securing such Lien.

      “Indenture” means the Base Indenture, as supplemented by this Supplemental Indenture, governing the Notes, in each case, as amended, supplemented or otherwise modified from time to time in accordance with its respective terms.

     “ Independent Financial Advisor ” means an accounting, appraisal, investment banking firm or consultant to Persons engaged in a Permitted Business of nationally recognized standing that is, in the good faith judgment of the Company, qualified to perform the task for which it has been engaged.

     “ Indirect Participant ” means a Person who holds a beneficial interest in a Global Note through a Participant.

     “ Initial Notes ” means the first $700 million aggregate principal amount of Notes issued under this Supplemental Indenture on the Issue Date.

     “ Investment Grade Rating ” means a rating equal to or higher than BBB- (or the equivalent) by S&P and equal to or higher than Baa3 (or the equivalent) by Moody’s.

     “ Investments ” means, with respect to any Person, all direct or indirect investments by such Person in other Persons (including Affiliates) in the forms of loans (including Guarantees or other obligations), advances or capital contributions (excluding commission, travel and similar advances to officers and employees), purchases or other acquisitions for consideration of Indebtedness, Equity Interests or other securities, together with all items that are or would be classified as investments on a balance sheet prepared in accordance with GAAP. If the Company or any Subsidiary of the Company sells or otherwise disposes of any Equity Interests of any direct or indirect Subsidiary of the Company such that, after giving effect to any such sale or disposition, such Person is no longer a Subsidiary of the Company, the Company will be deemed to have made an Investment on the date of any such sale or disposition equal to the fair market value of the Company’s Investments in such Subsidiary that were not sold or disposed of in an amount determined as provided in the final paragraph of Section 4.07(b) hereof. The acquisition by the Company or any Subsidiary of the Company of a Person that holds an Investment in a third Person will be deemed to be an Investment by the Company or such Subsidiary in such third Person in an amount equal to the fair market value of the Investments held by the acquired Person in such third Person in an amount determined as provided in the final paragraph of Section 4.07(b) hereof. Except as otherwise

provided in the indenture, the amount of an Investment will be determined at the time the Investment is made and without giving effect to subsequent changes in value.

     Notwithstanding anything to the contrary herein, in the case of any Investment made by the Company or a Restricted Subsidiary of the Company in a Person substantially concurrently with a cash distribution by such Person to the Company or a Guarantor (a “ Concurrent Cash Distribution ”), then:

     (a) the Concurrent Cash Distribution shall be deemed to be Net Proceeds received in connection with an Asset Sale and applied as set forth above under Section 4.10 hereof; and

     (b) the amount of such Investment shall be deemed to be the fair market value of the Investment, less the amount of the Concurrent Cash Distribution.

     “ Issue Date ” means June 5, 2009.

     “ Itiquira ” shall mean Itiquira Energetica S.A.

     “ Itiquira Acquisition Sub ” shall have the meaning assigned to such term in the definition of Itiquira Refinancing hereof.

     “ Itiquira Refinancing ” means the transaction or series of related transactions pursuant to which (a) any or all of the outstanding preferred stock of Itiquira directly or indirectly held by Eletrobrás is acquired by Itiquira or a subsidiary of Tosli Acquisition BV (“ Itiquira Acquisition Sub ”) for an aggregate consideration not to exceed to $70,000,000, and, following such acquisition, such preferred stock is redeemed, repaid or otherwise retired or held as treasury stock or otherwise treated in accordance with the requirements of Brazilian law, and (b) pursuant to which Itiquira or the Itiquira Acquisition Sub may incur up to $70,000,000 in aggregate principal amount of Indebtedness secured by Liens on the assets of Itiquira and the Itiquira Acquisition Sub (“ Permitted Itiquira Indebtedness ”), in each case on terms and conditions (which may include terms and conditions other than those set forth in this definition) reasonably satisfactory to the Administrative Agent under the Credit Agreement.

      “Legal Holiday” means a Saturday, a Sunday or a day on which banking institutions in the City of New York or at a place of payment are authorized by law, regulation or executive order to remain closed. If a payment date is a Legal Holiday at a place of payment, payment may be made at that place on the next succeeding day that is not a Legal Holiday, and no interest shall accrue on such payment for the intervening period.

     “ Lien ” means, with respect to any asset:

     (1) any mortgage, deed of trust, deed to secure debt, lien (statutory or otherwise), pledge, hypothecation, encumbrance, restriction, collateral assignment, charge or security interest in, on or of such asset;

     (2) the interest of a vendor or a lessor under any conditional sale agreement, capital lease or title retention agreement (or any financing lease having substantially the same economic effect as any of the foregoing) relating to such asset; and

     (3) in the case of Equity Interests or debt securities, any purchase option, call or similar right of a third party with respect to such Equity Interests or debt securities.

For the avoidance of doubt, “Lien” shall not be deemed to include licenses of intellectual property.

     “ Mark-to-Market Adjustments ” means:

     (1) any non-cash loss attributable to the mark-to-market movement in the valuation of Hedging Obligations (to the extent the cash impact resulting from such loss has not been realized) or other derivative instruments pursuant to Financial Accounting Standards Board Statement No. 133, “Accounting for Derivative Instruments and Hedging Activities,” or any similar successor provision; plus

     (a) any loss relating to amounts paid in cash prior to the stated settlement date of any Hedging Obligation that has been reflected in Consolidated Net Income in the current period; plus

     (b) any gain relating to Hedging Obligations associated with transactions recorded in the current period that has been reflected in Consolidated Net Income in prior periods and excluded from Consolidated Cash Flow pursuant to clauses (2)(a) and (2)(b) below; less ,

     (2) any non-cash gain attributable to the mark-to-market movement in the valuation of Hedging Obligations (to the extent the cash impact resulting from such gain has not been realized) or other derivative instruments pursuant to Financial Accounting Standards Board Statement No. 133, “Accounting for Derivative Instruments and Hedging Activities,” or any similar successor provision; less

     (a) any gain relating to amounts received in cash prior to the stated settlement date of any Hedging Obligation that has been reflected in Consolidated Net Income in the current period; less

     (b) any loss relating to Hedging Obligations associated with transactions recorded in the current period that has been reflected in Consolidated Net Income in prior periods and excluded from Consolidated Cash Flow pursuant to clauses (1)(a) and (1)(b) above.

      “Minority Investment” shall mean any Person (other than a Subsidiary) in which the Company or any Restricted Subsidiary owns Capital Stock.

     “ Moody’s ” means Moody’s Investors Service, Inc. or any successor entity.

     “ Necessary CapEx Debt ” shall mean Indebtedness of the Company or its Restricted Subsidiaries incurred for the purpose of financing Necessary Capital Expenditures.

     “ Necessary Capital Expenditures ” shall mean capital expenditures that are required by Applicable Law (other than Environmental Laws) or undertaken for health and safety reasons. The term “Necessary Capital Expenditures” does not include any capital expenditure undertaken primarily to increase the efficiency of, expand or re-power any power generation facility.

     “ Net Income ” means, with respect to any specified Person, the net income (loss) of such Person, determined in accordance with GAAP and before any reduction in respect of preferred stock dividends or accretion, excluding, however:

     (1) any gain or loss, together with any related provision for taxes on such gain or loss, realized in connection with: (a) any Asset Sale (without giving effect to the threshold provided for in the definition thereof); or (b) the disposition of any securities by such Person or any of its Restricted Subsidiaries or the extinguishment of any Indebtedness of such Person or any of its Restricted Subsidiaries; and

     (2) any extraordinary gain or loss, together with any related provision for taxes on such extraordinary gain or loss.

     “ Net Proceeds ” means the aggregate cash proceeds received by the Company or any of its Restricted Subsidiaries in respect of any Asset Sale (including, without limitation, any cash received upon the sale or other disposition of any non-cash consideration received in any Asset Sale), net of the direct costs relating to such Asset Sale, including, without limitation, legal, accounting and investment banking fees, and sales commissions, and any relocation expenses incurred as a result of the Asset Sale, taxes paid or payable as a result of the Asset Sale, in each case, after taking into account any available tax deductions and any tax sharing arrangements, and amounts required to be applied to the repayment of Indebtedness, other than Indebtedness under a Credit Facility, secured by a Lien on the asset or assets that were the subject of such Asset Sale and any reserve for adjustment in respect of the sale price of such asset or assets established in accordance with GAAP.

     “ Non-Recourse Debt ” means Indebtedness:

     (1) as to which neither the Company nor any of its Restricted Subsidiaries (other than an Excluded Project Subsidiary) (a) provides credit support of any kind (including any undertaking, agreement or instrument that would constitute Indebtedness) other than pursuant to a Non-Recourse Guarantee or any arrangement to provide or guarantee to provide goods and services on an arm’s length basis, (b) is directly or indirectly liable as a guarantor or otherwise, other than pursuant to a Non-Recourse Guarantee, or (c) constitutes the lender;

     (2) no default with respect to which (including any rights that the holders of the Indebtedness may have to take enforcement action against an Unrestricted Subsidiary) would permit upon notice, lapse of time or both any holder of any other Indebtedness of the Company (other than the notes and the Credit Agreement) or any of its Restricted Subsidiaries to declare a default on such other Indebtedness or cause the payment of such other Indebtedness to be accelerated or payable prior to its Stated Maturity; and

     (3) in the case of Non-Recourse Debt incurred after the Issue Date, as to which the lenders have been notified in writing, or have otherwise agreed, that they will not have any recourse to the stock or assets of the Company or any of its Restricted Subsidiaries except as otherwise permitted by clauses (1) or (2) above;

provided , however , that the following shall be deemed to be Non-Recourse Debt: (i) Guarantees with respect to debt service reserves established with respect to a Subsidiary to the extent that such Guarantee shall result in the immediate payment of funds, pursuant to dividends or otherwise, in the amount of such Guarantee; (ii) contingent obligations of the Company or any other Subsidiary to make capital contributions to a Subsidiary; (iii) any credit support or liability consisting of reimbursement obligations in respect of Letters of Credit issued under and subject to the terms of, the Credit Agreement to support obligations of a Subsidiary; (iv) agreements of the Company or any Subsidiary to provide, or guarantees or other credit support (including letters of credit) by the Company or any Subsidiary of any agreement of another Subsidiary to provide, corporate, management, marketing, administrative, technical, energy management or marketing, engineering, procurement, construction, operation and/or maintenance services to such Subsidiary, including in respect of the sale or acquisition of power, emissions, fuel, oil, gas or other supply of energy; (v) any agreements containing Hedging Obligations, and any power purchase or sale agreements, fuel purchase or sale agreements, emissions credit purchase or sales agreements, power transmission agreements, fuel transportation agreements, fuel storage agreements, commercial or trading agreements and any other similar agreements entered into between the Company or any Subsidiary with or otherwise involving any other Subsidiary, including any guarantees or other credit

support (including letters of credit) in connection therewith; and (vi) any Investments in a Subsidiary, to the extent in the case of (i) through (vi) otherwise permitted by this Supplemental Indenture.

     “ Non-Recourse Guarantee ” means any Guarantee by the Company or a Guarantor of Non-Recourse Debt incurred by an Excluded Project Subsidiary as to which the lenders of such Non-Recourse Debt have acknowledged that they will not have any recourse to the stock or assets of the Company or any Guarantor, except to the limited extent set forth in such guarantee.

     “ Notes ” has the meaning assigned to it in the preamble to this Supplemental Indenture. The Initial Notes and the Additional Notes shall be treated as a single class for all purposes under this Supplemental Indenture. Unless the context otherwise requires, all references to the Notes shall include the Initial Notes and any Additional Notes.

     “ Obligations ” means any principal, interest, penalties, fees, indemnifications, reimbursements, damages and other liabilities payable under the documentation governing any Indebtedness.

      “Officers’ Certificate” means a certificate signed on behalf of the Company by two Officers of the Company, one of whom must be the principal executive officer, the principal financial officer, the treasurer or the principal accounting officer of the Company, that meets the requirements of Section 12.05 hereof.

      “Opinion of Counsel” means an opinion from legal counsel who is reasonably acceptable to the Trustee, that meets the requirements of Section 12.05 hereof. The counsel may be an employee of or counsel to the Company, any Subsidiary of the Company or the Trustee.

     “ Officer ” means, with respect to any Person, the Chairman of the Board, the Chief Executive Officer, the President, the Chief Operating Officer, the Chief Financial Officer, the Treasurer, any Assistant Treasurer, the Controller, the Secretary, Assistant Secretary, or any Vice-President of such Person.

     “ Participant ” means, with respect to the Depositary, a Person who has an account with the Depositary.

     “ Permitted Business ” means the business of acquiring, constructing, managing, developing, improving, maintaining, leasing, owning and operating Facilities, together with any related assets or facilities, as well as any other activities reasonably related to, ancillary to, or incidental to, any of the foregoing activities (including acquiring and holding reserves), including investing in Facilities.

     “ Permitted Investments ” means:

     (1) any Investment in the Company or in a Restricted Subsidiary of the Company that is a Guarantor;

     (2) any Investment in an Immaterial Subsidiary;

     (3) any Investment in an Excluded Foreign Subsidiary for so long as the Excluded Foreign Subsidiaries do not collectively own more than 20% of the consolidated assets of the Company as of the most recent fiscal quarter end for which financial statements are publicly available;

     (4) any issuance of letters of credit to support the obligations of any of the Excluded Subsidiaries;

     (5) any Investment in Cash Equivalents (and, in the case of Excluded Subsidiaries only, Cash Equivalents or other liquid investments permitted under any Credit Facility to which it is a party);

     (6) any Investment by the Company or any Restricted Subsidiary of the Company in a Person, if as a result of such Investment:

          (A) such Person becomes a Restricted Subsidiary of the Company and a Guarantor or an Immaterial Subsidiary; or

          (B) such Person is merged, consolidated or amalgamated with or into, or transfers or conveys substantially all of its assets to, or is liquidated into, the Company or a Restricted Subsidiary of the Company that is a Guarantor;

     (7) any Investment made as a result of the receipt of non-cash consideration from an Asset Sale that was made pursuant to and in compliance with Section 4.10 hereof;

     (8) Investments made as a result of the sale of Equity Interests of any Person that is a Subsidiary of the Company such that, after giving effect to any such sale, such Person is no longer a Subsidiary of the Company, if the sale of such Equity Interests constitutes an Asset Sale and the Net Proceeds received from such Asset Sale are applied as set forth under Section 4.10 hereof;

     (9) Investments to the extent made in exchange for the issuance of Equity Interests (other than Disqualified Stock) of the Company;

     (10) any Investments received in compromise or resolution of (a) obligations of trade creditors or customers of the Company or any of its Restricted Subsidiaries, including pursuant to any plan of reorganization or similar arrangement upon the bankruptcy or insolvency of any trade creditor or customer; or (b) litigation, arbitration or other disputes with Persons who are not Affiliates;

     (11) Investments represented by Hedging Obligations;

     (12) loans or advances to employees;

     (13) repurchases of the notes or pari passu Indebtedness;

     (14) any Investment in securities of trade creditors, trade counter-parties or customers received in compromise of obligations of those Persons, including pursuant to any plan of reorganization or similar arrangement upon the bankruptcy or insolvency of such trade creditors or customers;

     (15) negotiable instruments held for deposit or collection;

     (16) receivables owing to the Company or any Restricted Subsidiary of the Company and payable or dischargeable in accordance with customary trade terms; provided ,

however , that such trade terms may include such concessionary trade terms as the Company of any such Restricted Subsidiary of the Company deems reasonable under the circumstances;

     (17) payroll, travel and similar advances to cover matters that are expected at the time of such advances ultimately to be treated as expenses for accounting purposes;

     (18) Investments resulting from the acquisition of a Person that at the time of such acquisition held instruments constituting Investments that were not acquired in contemplation of the acquisition of such Person;

     (19) any Investment in any Person engaged primarily in one or more Permitted Businesses (including, without limitation, Excluded Subsidiaries, Unrestricted Subsidiaries, and Persons that are not Subsidiaries of the Company) made for cash since the Issue Date;

     (20) the contribution of any one or more of the Specified Facilities to a Restricted Subsidiary that is not a Guarantor;

     (21) Investments made pursuant to a commitment that, when entered into, would have complied with the provisions of this Supplemental Indenture;

     (22) Investments in any Excluded Subsidiary made by another Excluded Subsidiary; and

     (23) other Investments made since the Issue Date in any Person having an aggregate fair market value (measured on the date each such Investment was made and without giving effect to subsequent changes in value), when taken together with all other Investments made pursuant to this clause (23) that are at the time outstanding not to exceed the greater of (a) $500.0 million and (b) 2.5% of Total Assets; provided , however , that if any Investment pursuant to this clause (23) is made in any Person that is not a Restricted Subsidiary of the Company and a Guarantor at the date of the making of the Investment and such Person becomes a Restricted Subsidiary and a Guarantor after such date, such Investment shall thereafter be deemed to have been made pursuant to clause (1) above, and shall cease to have been made pursuant to this clause (23).

     “ Permitted Itiquira Indebtedness ” shall have the meaning assigned to such term in the definition of Itiquira Refinancing hereof.

     “ Permitted Liens ” means:

     (1) Liens on assets of the Company or any Guarantor securing Indebtedness and other Obligations under Credit Facilities, in an aggregate principal amount not exceeding, on the date of the creation of such Liens, the greater of (a) 30.0% of Total Assets or (b) $6.0 billion less the aggregate amount of all repayments, optional or mandatory, of the principal of any term Indebtedness under a Credit Facility that have been made by the Company or any of its Restricted Subsidiaries since the Issue Date with the Net Proceeds of Asset Sales (other than Excluded Proceeds) and less, without duplication, the aggregate amount of all repayments or commitment reductions with respect to any revolving credit borrowings under a Credit Facility that have been made by the Company or any of its Restricted Subsidiaries since the Issue Date as a result of the application of the Net Proceeds of Asset Sales (other than Excluded Proceeds) in accordance with

Section 4.10 hereof (excluding temporary reductions in revolving credit borrowings as contemplated by that covenant);

     (2) Liens to secure obligations with respect to (i) contracts (other than for Indebtedness) for commercial and trading activities for the purchase, transmission, distribution, sale, lease or hedge of any energy related commodity or service, and (ii) Hedging Obligations;

     (3) Liens on assets of Excluded Subsidiaries securing Indebtedness and/or other obligations of Excluded Subsidiaries that was permitted by the terms of the indenture to be incurred;

     (4) Liens (a) in favor of the Company or any of the Guarantors; (b) incurred by Excluded Project Subsidiaries in favor of any other Excluded Project Subsidiary; or (c) incurred by Excluded Foreign Subsidiaries in favor of any other Excluded Foreign Subsidiary;

     (5) Liens to secure the performance of statutory obligations, surety or appeal bonds, performance bonds or other obligations of a like nature;

     (6) Liens to secure obligations to vendors or suppliers covering the assets sold or supplied by such vendors or suppliers, including Liens to secure Indebtedness or other obligations (including Capital Lease Obligations) permitted by clauses (4), (13), (20) and (21) of Section 4.09(b) hereof covering only the assets acquired with or financed by such Indebtedness;

     (7) Liens existing on the Issue Date;

     (8) Liens for taxes, assessments or governmental charges or claims that are not yet delinquent or that are being contested in good faith by appropriate proceedings promptly instituted and diligently concluded; provided that any reserve or other appropriate provision as is required in conformity with GAAP has been made therefor;

     (9) Liens imposed by law, such as carriers’, warehousemen’s, landlord’s and mechanics’ Liens;

     (10) survey exceptions, easements or reservations of, or rights of others for, licenses, rights-of-way, sewers, electric lines, telegraph and telephone lines, oil and gas and other mineral interests and leases and other similar purposes, or zoning or other restrictions as to the use of real property that were not incurred in connection with Indebtedness and that do not in the aggregate materially adversely affect the value of said properties or materially impair their use in the operation of the business of such Person;

     (11) Liens created for the benefit of (or to secure) the notes (or the Subsidiary Guarantees);

     (12) Liens to secure any Permitted Refinancing Indebtedness permitted to be incurred under this Supplemental Indenture; provided , however , that:

          (A) the new Lien shall be limited to all or part of the same property and assets that secured or, under the written agreements pursuant to which the original Lien arose, could secure the original Lien (plus improvements and accessions to, such property or proceeds or distributions thereof); and

          (B) the Indebtedness secured by the new Lien is not increased to any amount greater than the sum of (x) the outstanding principal amount or, if greater, committed amount, of the Permitted Referencing Indebtedness and (y) an amount necessary to pay any fees and expenses, including premiums, related to such refinancings, refunding, extension, renewal or replacement;

     (13) Liens incurred or deposits made in connection with workers’ compensation, unemployment insurance and other types of social security;

     (14) Liens encumbering deposits made to secure obligations arising from statutory, regulatory, contractual or warranty requirements of the Company or any of its Restricted Subsidiaries, including rights of offset and set-off;

     (15) leases or subleases granted to others that do not materially interfere with the business of the Company and its Restricted Subsidiaries;

     (16) statutory Liens arising under ERISA;

     (17) Liens on property (including Capital Stock) existing at the time of acquisition of the property by the Company or any Subsidiary of the Company; provided that such Liens were in existence prior to, such acquisition, and not incurred in contemplation of, such acquisition;

     (18) Liens arising from Uniform Commercial Code financing statements filed on a precautionary basis in respect of operating leases intended by the parties to be true leases (other than any such leases entered into in violation of the indenture);

     (19) Liens on assets and Equity Interests of a Subsidiary that is an Excluded Subsidiary;

     (20) Liens granted in favor of Xcel pursuant to the Xcel Indemnification Agreements as in effect on the Issue Date held by Xcel thereunder;

     (21) Liens to secure Indebtedness or other obligations incurred to finance Necessary Capital Expenditures that encumber only the assets purchased, installed or otherwise acquired with the proceeds of such Indebtedness;

     (22) Liens to secure Environmental CapEx Debt that encumber only the assets purchased, installed or otherwise acquired with the proceeds of such Environmental CapEx Debt;

     (23) Liens on assets or securities deemed to arise in connection with the execution, delivery or performance of contracts to sell such assets or stock otherwise permitted under this Supplemental Indenture;

     (24) Liens on assets of Itiquira incurred pursuant to the Itiquira Refinancing;

     (25) any Liens resulting from restrictions on any Equity Interest or undivided interests, as the case may be, of a Person providing for a breach, termination or default under any joint venture, stockholder, membership, limited liability company, partnership, owners’, participation or other similar agreement between such Person and one or more other holders of Equity Interests or undivided interests of such Person, as the case may be, if a security interest or

Lien is created on such Equity Interest or undivided interest, as the case may be, as a result thereof;

     (26) Liens resulting from any customary provisions limiting the disposition or distribution of assets or property (including without limitation Equity Interests) or any related restrictions thereon in joint venture, partnership, membership, stockholder and limited liability company agreements, asset sale agreements, sale-leaseback agreements, stock sale agreements and other similar agreements, including owners’, participation or similar agreements governing projects owned through an undivided interest; provided, however , that any such limitation is applicable only to the assets that are the subjects of such agreements;

     (27) those Liens or other exceptions to title, in either case on or in respect of any facility of the Company or any Subsidiary, arising as a result of any shared facility agreement entered into after the closing date with respect to such facility, except to the extent that any such Liens or exceptions, individually or in the aggregate, materially adversely affect the value of the relevant property or materially impair the use of the relevant property in the operation of the business of the Company or such Subsidiary;

     (28) Liens on cash deposits and other funds maintained with a depositary institution, in each case arising in the ordinary course of business by virtue of any statutory or common law provision relating to banker’s liens, including Section 4-210 of the UCC;

     (29) any Liens on property and assets (other than certain properties or assets defined as “core” collateral) designated as Excluded Assets from time to time by the Company under clause (xiii) of the related definition under the Credit Agreement, which shall not have, when taken together with all other “non-core” property and assets that constitute Excluded Assets pursuant to such clause at the relevant time of determination, a fair market value in excess of $500.0 million in the aggregate (and, to the extent that such fair market value of such property and assets exceeds $500.0 million in the aggregate, such property or assets shall cease to be an Excluded Asset only to the extent of such excess fair market value); and

     (30) Liens incurred by the Company or any Subsidiary of the Company with respect to obligations not to exceed $500.0 million at any one time outstanding.

     “ Permitted Refinancing Indebtedness ” means any Indebtedness of the Company or any of its Restricted Subsidiaries issued in exchange for, or the net proceeds of which are used to refund, refinance, replace, defease or discharge other Indebtedness of the Company or any of its Restricted Subsidiaries (other than intercompany Indebtedness); provided that:

     (1) the principal amount (or accreted value, if applicable) of such Permitted Refinancing Indebtedness does not exceed the principal amount (or accreted value, if applicable) of the Indebtedness extended, refinanced, renewed, replaced, defeased or refunded (plus all accrued interest on the Indebtedness and the amount of all expenses and premiums incurred in connection therewith);

     (2) such Permitted Refinancing Indebtedness has a Weighted Average Life to Maturity equal to or greater than the Weighted Average Life to Maturity of, the Indebtedness being extended, refinanced, renewed, replaced, defeased or refunded;

     (3) if the Indebtedness being extended, refinanced, renewed, replaced, defeased or refunded is subordinated in right of payment to the Notes, such Permitted

Refinancing Indebtedness is subordinated in right of payment to, the Notes on terms at least as favorable to the Holders of Notes as those contained in the documentation governing the Indebtedness being extended, refinanced, renewed, replaced, defeased or refunded;

     (4) such Indebtedness is incurred either by the Company (and may be guaranteed by any Guarantor) or by the Restricted Subsidiary who is the obligor on the Indebtedness being extended, refinanced, renewed, replaced, defeased or refunded; and

     (5) (a) if the Stated Maturity of the Indebtedness being refinanced is earlier than the Stated Maturity of the notes, the Permitted Refinancing Indebtedness has a Stated Maturity no earlier than the Stated Maturity of the Indebtedness being refinanced or (b) if the Stated Maturity of the Indebtedness being refinanced is later than the Stated Maturity of the Notes, the Permitted Refinancing Indebtedness has a Stated Maturity at least 91 days later than the Stated Maturity of the Notes.

     “ Permitted Tax Lease ” means a sale and leaseback transaction consisting of a “payment in lieu of taxes” program or any similar structure (including but not limited to leases and sale-leasebacks) primarily intended to provide tax benefits (and not primarily intended to create Indebtedness).

     “ Person ” means any individual, corporation, partnership, joint venture, association, joint-stock company, trust, unincorporated organization, limited liability company or government or other entity.

     “ PMI ” means NRG Power Marketing Inc., a Delaware corporation.

     “ Pro Forma Cost Savings ” means, without duplication, with respect to any period, reductions in costs and related adjustments that have been actually realized or are projected by the Company’s Chief Financial Officer in good faith to result from reasonably identifiable and factually supportable actions or events, but only if such reductions in costs and related adjustments are so projected by the Company to be realized during the consecutive four-quarter period commencing after the transaction giving rise to such calculation.

     “ Prospectus Supplement ” means the Prospectus Supplement, dated June 2, 2009, related to the issuance and sale of the Initial Notes.

     “ Prudent Industry Practice ” shall mean those practices and methods as are commonly used or adopted by Persons in the Permitted Business in the United States in connection with the conduct of the business of such industry, in each case as such practices or methods may evolve from time to time, consistent in all material respects with all applicable legal requirements.

     “ Qualifying Equity Interests ” means Equity Interests of the Company other than (1) Disqualified Stock; (2) Equity Interests that were used to support an incurrence of Contribution Indebtedness and (3) Equity Interests sold in an Equity Offering prior to the third anniversary of the Issue Date that are eligible to be used to support an optional redemption of notes pursuant to Section 3.07 hereof.

     “ Responsible Officer ” of a Person means the chief executive officer, chief financial officer, treasurer or general counsel of such Person.

     “ Restricted Investment ” means an Investment other than a Permitted Investment.

     “ Restricted Payments ” has the meaning assigned to such term under Section 4.07 hereof. For purposes of determining compliance with Section 4.07 hereof, no Hedging Obligation shall be deemed to be contractually subordinated to the notes or any Subsidiary Guarantee.

     “ Restricted Subsidiary ” of a Person means any Subsidiary of the referent Person that is not an Unrestricted Subsidiary.

     “ S&P ” means Standard & Poor’s Financial Services LLC or any successor entity.

      “SEC” means the Securities and Exchange Commission.

      “Second Supplemental Indenture” means the Second Supplemental Indenture, dated February 2, 2006, governing NRG’s 7.375% Senior Notes due 2016.

      “Securities Act” means the Securities Act of 1933, as amended.

     “ Significant Subsidiary ” means any Subsidiary that would be a “significant subsidiary” as defined in Article 1, Rule 1-02 of Regulation S-X, promulgated pursuant to the Securities Act, as such Regulation is in effect on the Issue Date.

     “ Specified Facility ” means each of the following Facilities, or any part thereof: (a) the Facilities held on the Issue Date by Vienna Power LLC, Meriden Gas Turbine LLC, Norwalk Power LLC, Connecticut Jet Power LLC (excluding the Cos Cob assets), Devon Power LLC, Montville Power LLC (including the Capital Stock of the entities owning such Facilities provided that such entities do not hold material assets other than the Facilities held on the Issue Date); (b) the following Facilities: P.H. Robinson, H.O. Clarke, Webster, Unit 3 at Cedar Bayou, Unit 2 at T.H. Wharton; and (c) the Capital Stock of the following Subsidiaries of the Company if such Subsidiary holds no assets other than the Capital Stock of a Foreign Subsidiary of the Company: NRG Latin America, Inc., NRG International LLC, NRG Insurance Ltd. (Cayman Islands), NRG Asia Pacific, Ltd., NRG International II Inc. and NRG International III Inc.

     “ Stated Maturity ” means, with respect to any installment of interest or principal on any series of Indebtedness, the date on which the payment of interest or principal was scheduled to be paid in the documentation governing such Indebtedness as of the Issue Date, and will not include any contingent obligations to repay, redeem or repurchase any such interest or principal prior to the date originally scheduled for the payment thereof.

     “ Subsidiary ” means, with respect to any specified Person:

     (1) any corporation, association or other business entity of which more than 50% of the total voting power of shares of Capital Stock entitled (without regard to the occurrence of any contingency and after giving effect to any voting agreement or stockholders’ agreement that effectively transfers voting power) to vote in the election of directors, managers or trustees of the corporation, association or other business entity is at the time owned or controlled, directly or indirectly, by that Person or one or more of the other Subsidiaries of that Person (or a combination thereof); and

     (2) any partnership (a) the sole general partner or the managing general partner of which is such Person or a Subsidiary of such Person or (b) the only general partners of which are that Person or one or more Subsidiaries of that Person (or any combination thereof).

     “ Subsidiary Guarantee ” means the Guarantee by each Guarantor of the Company’s obligations under the Indenture and on the Notes, executed pursuant to the provisions of this Supplemental Indenture.

     “ Supplemental Indenture ” means this Supplemental Indenture, dated as of the Issue Date, by and among the Company, the Guarantors and the Trustee, governing the Notes, as amended, supplemented or otherwise modified from time to time in accordance with the Base Indenture and the terms hereof.

      “TIA” means the Trust Indenture Act of 1939, as amended (15 U.S.C. §§ 77aaa-77bbbb).

     “ Total Assets ” means the total consolidated assets of the Company and its Restricted Subsidiaries, determined on a consolidated basis in accordance with GAAP, as shown on the most recent balance sheet of the Company.

     “ Total Debt ” means, as of any date of determination, the aggregate principal amount of Indebtedness of the Company and its Restricted Subsidiaries (other than Excluded Project Subsidiaries) outstanding on such date, determined on a consolidated basis in accordance with GAAP; provided that (1) Total Debt will include only the amount of payments that the Company or any of its Restricted Subsidiaries (other than Excluded Project Subsidiaries) would be required to make, on the date Total Debt is being determined, in the event of any early termination or similar event on such date of determination and (2) for the avoidance of doubt, Total Debt will not include the undrawn amount of any outstanding letters of credit.

     “ Treasury Rate ” means, as of any redemption date, the yield to maturity as of such redemption date of United States Treasury securities with a constant maturity (as compiled and published in the most recent Federal Reserve Statistical Release H.15 (519) that has become publicly available at least two business days prior to the redemption date (or, if such Statistical Release is no longer published, any publicly available source of similar market data)) most nearly equal to the period from the redemption date to June 15, 2014; provided , however , that if the period from the redemption date to June 15, 2014, is less than one year, the weekly average yield on actually traded United States Treasury securities adjusted to a constant maturity of one year will be used.

     “ UCC ” means the Uniform Commercial Code as in effect in the State of New York or any other applicable jurisdiction.

     “ Unrestricted Subsidiary ” means any Subsidiary of the Company that is designated by the Company as an Unrestricted Subsidiary pursuant to a certificate executed by a Responsible Officer of the Company, but only to the extent that such Subsidiary:

     (1) has no Indebtedness other than Non-Recourse Debt;

     (2) except as permitted by Section 4.11 hereof, is not party to any agreement, contract, arrangement or understanding with the Company or any Restricted Subsidiary of the Company unless the terms of any such agreement, contract, arrangement or understanding are no less favorable to the Company or such Restricted Subsidiary than those that might be obtained at the time from Persons who are not Affiliates of the Company;

     (3) is a Person with respect to which neither the Company nor any of its Restricted Subsidiaries has any direct or indirect obligation (a) to subscribe for additional Equity Interests or (b) to maintain or preserve such Person’s financial condition or to cause such Person to achieve any specified levels of operating results except as otherwise permitted by the Credit Agreement as in effect on the Issue Date; and

     (4) has not guaranteed or otherwise directly or indirectly provided credit support for any Indebtedness of the Company or any of its Restricted Subsidiaries except as otherwise permitted by the Credit Agreement as in effect on the Issue Date.

     Any designation of a Subsidiary of the Company as an Unrestricted Subsidiary will be evidenced to the Trustee by filing with the Trustee a certified copy of the certificate executed by a Responsible Officer of the Company giving effect to such designation and certifying that such designation complied with the conditions described under Section 4.19 hereof and was permitted by Section 4.07 hereof. If, at any time, any Unrestricted Subsidiary fails to meet the requirements as an Unrestricted Subsidiary, it will thereafter cease to be an Unrestricted Subsidiary for purposes of this Supplemental Indenture and any Indebtedness of such Subsidiary will be deemed to be incurred by a Restricted Subsidiary of the Company as of such date and, if such Indebtedness is not permitted to be incurred as of such date under Section 4.09 hereof, the Company will be in default of such covenant. The Company may at any time designate any Unrestricted Subsidiary to be a Restricted Subsidiary; provided that such designation will be deemed to be an incurrence of Indebtedness by a Restricted Subsidiary of the Company of any outstanding Indebtedness of such Unrestricted Subsidiary and such designation will only be permitted if (1) such Indebtedness is permitted under Section 4.09 hereof, calculated on a pro forma basis as if such designation had occurred at the beginning of the four-quarter reference period; and (2) no Default or Event of Default would be in existence following such designation.

     “ Voting Stock ” of any Person as of any date means the Capital Stock of such Person that is at the time entitled to vote in the election of the Board of Directors of such Person.

     “ Weighted Average Life to Maturity ” means, when applied to any Indebtedness at any date, the number of years obtained by dividing:

     (1) the sum of the products obtained by multiplying (a) the amount of each then remaining installment, sinking fund, serial maturity or other required payments of principal, including payment at final maturity, in respect of the Indebtedness, by (b) the number of years (calculated to the nearest one-twelfth) that will elapse between such date and the making of such payment; by

     (2) the then outstanding principal amount of such Indebtedness.

     “ Xcel ” means Xcel Energy Inc., a Minnesota corporation.

     “ Xcel Indemnification Agreements ” means: (i) the Indemnification Agreement, dated as of December 5, 2003, between Xcel Energy Inc., Northern States Power Company and the Company; and (ii) the Indemnification Agreement, dated as of December 5, 2003, between Xcel Energy Inc., Northern States Power Company and the Company.

     Section 1.02 Other Definitions.

     Section 1.03 Incorporation by Reference of Trust Indenture Act.

     Whenever this Supplemental Indenture refers to a provision of the TIA, the provision is incorporated by reference in and made a part of this Supplemental Indenture.

     The following TIA terms used in this Supplemental Indenture have the following meanings:

     “ obligor ” on the Notes and the Subsidiary Guarantees means the Company and the Guarantors, respectively, and any successor obligor upon the Notes and the Subsidiary Guarantees, respectively.

     All other terms used in this Supplemental Indenture that are defined by the TIA, defined by TIA reference to another statute or defined by SEC rule under the TIA have the meanings so assigned to them. All other capitalized terms used herein and not otherwise defined shall have the meanings provided in the Base Indenture.

     Section 1.04 Rules of Construction.

     Unless the context otherwise requires:

     (1) a term has the meaning assigned to it;

     (2) an accounting term not otherwise defined has the meaning assigned to it in accordance with GAAP;

     (3) “or” is not exclusive;

     (4) words in the singular include the plural, and in the plural include the singular;

     (5) “will” shall be interpreted to express a command;

     (6) provisions apply to successive events and transactions;

     (7) references to sections of or rules under the Securities Act will be deemed to include substitute, replacement of successor sections or rules adopted by the SEC from time to time; and

     (8) references to sections of the Indenture refer to sections of this Supplemental Indenture.

     Section 1.05 Relationship with Base Indenture.

     The terms and provisions contained in the Base Indenture shall constitute, and are hereby expressly made, a part of this Supplemental Indenture and the Company, the Guarantors and the Trustee, by their execution and delivery of this Supplemental Indenture, expressly agree to such terms and provisions and to be bound thereby. However, to the extent any provision of the Base Indenture conflicts with the express provisions of this Supplemental Indenture, the provisions of this Supplemental Indenture shall govern and be controlling.

     The Trustee accepts the amendment of the Base Indenture effected by this Supplemental Indenture and agrees to execute the trust created by the Base Indenture as hereby amended, but only upon the terms and conditions set forth in the Indenture, including the terms and provisions defining and limiting the liabilities and responsibilities of the Trustee in the performance of the trust created by the Base Indenture, and without limiting the generality of the foregoing, the Trustee shall not be responsible in any manner whatsoever for or with respect to any of the recitals or statements contained herein, all of which recitals or statements are made solely by the Company and the Guarantors, or for or with respect to (1) the validity or sufficiency of this Supplemental Indenture or any of the terms or provisions hereof, (2) the proper authorization hereof by the Company and the Guarantors, (3) the due execution hereof by the Company and the Guarantors or (4) the consequences (direct or indirect and whether deliberate or inadvertent) of any amendment herein provided for, and the Trustee makes no representation with respect to any such matters.

ARTICLE 2.
THE NOTES

     Section 2.01 Form and Dating.

     (a)  General . The Notes shall be issued in registered global form without interest coupons. The Notes and the Trustee’s certificate of authentication shall be substantially in the form of Exhibit A hereto. The Notes may have notations, legends or endorsements required by law, stock exchange rule or usage. The Company shall furnish any such notations, legends or endorsements to the Trustee in writing. Each Note shall be dated the date of its authentication. The Notes shall be in denominations of $5,000 and integral multiples of $5,000.

     The terms and provisions contained in the Notes shall constitute, and are hereby expressly made, a part of the Indenture and the Company, the Guarantors and the Trustee, by their execution and delivery of this Supplemental Indenture, expressly agree to such terms and provisions and to be bound thereby. However, to the extent any provision of any Note conflicts with the express provisions of the Base Indenture, the provisions of the Note shall govern and be controlling, and to the extent any provision of the Note conflicts with the express provisions of this Supplemental Indenture, the provisions of this Supplemental Indenture shall govern and be controlling.

     (b)  Global Notes . Notes issued in global form shall be substantially in the form of Exhibit A attached hereto (including the Global Note Legend thereon). Notes issued in definitive form shall be substantially in the form of Exhibit A attached hereto (but without the Global Note Legend thereon). Each Global Note shall represent such of the outstanding Notes as will be specified therein and each shall provide that it represents the aggregate principal amount of outstanding Notes from time to time as reflected in the records of the Trustee and that the aggregate principal amount of outstanding Notes represented thereby may from time to time be reduced or increased, as appropriate, to reflect exchanges and redemptions. The Trustee’s records shall be noted to reflect the amount of any increase or decrease

in the aggregate principal amount of outstanding Notes represented thereby, in accordance with instructions given by the Holder thereof as required by Section 2.04 hereof.

     Section 2.02 Execution and Authentication.

     One Officer must sign the Notes for the Company by manual or facsimile signature.

     If an Officer whose signature is on a Note no longer holds that office at the time a Note is authenticated, the Note will nevertheless be valid.

     A Note will not be valid until authenticated by the manual signature of the Trustee. The signature will be conclusive evidence that the Note has been authenticated under this Supplemental Indenture.

     The Trustee shall, upon receipt of a Company Order, authenticate Notes for original issue under this Supplemental Indenture, including any Additional Notes issued pursuant to Section 2.05 hereof. The aggregate principal amount of Notes outstanding at any time may not exceed the aggregate principal amount of Notes authorized for issuance by the Company pursuant to one or more Company Orders, except as provided in Section 2.8 of the Base Indenture.

     The Trustee may appoint an authenticating agent acceptable to the Company to authenticate Notes. An authenticating agent may authenticate Notes whenever the Trustee may do so. Each reference in this Supplemental Indenture to authentication by the Trustee includes authentication by such agent. An authenticating agent has the same rights as an Agent to deal with Holders, the Company or an Affiliate of the Company.

     Section 2.03 Holder Lists.

     The Trustee shall preserve in as current a form as is reasonably practicable the most recent list available to it of the names and addresses of all Holders and shall otherwise comply with TIA § 312(a). If the Trustee is not the Registrar, the Company shall furnish to the Trustee at least seven Business Days before each interest payment date and at such other times as the Trustee may request in writing, a list in such form and as of such date as the Trustee may reasonably require of the names and addresses of the Holders and the Company shall otherwise comply with TIA § 312(a).

     Section 2.04 Transfer and Exchange.

     (a)  Transfer and Exchange of Global Notes . A Global Note may not be transferred as a whole except by the Depositary to a nominee of the Depositary, by a nominee of the Depositary to the Depositary or to another nominee of the Depositary, or by the Depositary or any such nominee to a successor Depositary or a nominee of such successor Depositary. All Global Notes shall be exchanged by the Company for Definitive Notes if:

     (1) the Company delivers to the Trustee notice from the Depositary that it is unwilling or unable to continue to act as Depositary or that it is no longer a clearing agency registered under the Exchange Act and, in either case, a successor Depositary is not appointed by the Company within 120 days after the date of such notice from the Depositary;

     (2) the Company in its sole discretion determines that the Global Notes (in whole but not in part) should be exchanged for Definitive Notes and delivers a written notice to such effect to the Trustee; or

     (3) there has occurred and is continuing a Default or Event of Default with respect to the Notes.

     Upon the occurrence of any of the preceding events in (1), (2) or (3) above, Definitive Notes shall be issued in such names and in any approved denominations as the Depositary shall instruct the Trustee. Global Notes also may be exchanged or replaced, in whole or in part, as provided in Sections 2.8 and 2.11 of the Base Indenture. Every Note authenticated and delivered in exchange for, or in lieu of, a Global Note or any portion thereof, pursuant to this Section 2.04 hereof or Sections 2.8 and 2.11 of the Base Indenture, shall be authenticated and delivered in the form of, and shall be, a Global Note. A Global Note may not be exchanged for another Note other than as provided in this Section 2.04(a), however, beneficial interests in a Global Note may be transferred and exchanged as provided in Section 2.04(b), (c) and (d) hereof.

     (b)  Transfer and Exchange of Beneficial Interests in the Global Notes . The transfer and exchange of beneficial interests in the Global Notes shall be effected through the Depositary, in accordance with the provisions of this Supplemental Indenture and the Applicable Procedures. Transfers of beneficial interests in the Global Notes also will require compliance with either subparagraph (1) or (2) below, as applicable, as well as one or more of the other following subparagraphs, as applicable:

     (1) Transfer of Beneficial Interests in the Same Global Note . Beneficial interests in any Global Note may be transferred to Persons who take delivery thereof in the form of a beneficial interest in a Global Note. No written orders or instructions shall be required to be delivered to the Registrar to effect the transfers described in this Section 2.04(b)(1).

     (2) All Other Transfers and Exchanges of Beneficial Interests in Global Notes. In connection with all transfers and exchanges of beneficial interests that are not subject to Section 2.04(b)(1) above, the transferor of such beneficial interest must deliver to the Registrar both:

     (A) a written order from a Participant or an Indirect Participant given to the Depositary in accordance with the Applicable Procedures directing the Depositary to credit or cause to be credited a beneficial interest in another Global Note in an amount equal to the beneficial interest to be transferred or exchanged; and

     (B) instructions given in accordance with the Applicable Procedures containing information regarding the Participant account to be credited with such increase.

     Upon satisfaction of all of the requirements for transfer or exchange of beneficial interests in Global Notes contained in this Supplemental Indenture and the Notes or otherwise applicable under the Securities Act, the Trustee shall adjust the principal amount of the relevant Global Note(s) pursuant to Section 2.04(g) hereof.

     (c)  Transfer or Exchange of Beneficial Interests in Global Notes for Definitive Notes.

     (1) If any holder of a beneficial interest in a Global Note proposes to exchange such beneficial interest for a Definitive Note or to transfer such beneficial interest to a Person who takes delivery thereof in the form of a Definitive Note, then, upon satisfaction of the conditions set forth in Section 2.04(b)(2) hereof, the Trustee shall cause the aggregate principal amount of the applicable Global Note to be reduced accordingly pursuant to Section 2.04(g) hereof, and the Company shall execute and the Trustee shall authenticate and deliver to the Person designated in the instructions a Definitive Note in the appropriate principal amount. Any Definitive Note issued in exchange for a beneficial interest pursuant to this Section 2.04(c)(1)

shall be registered in such name or names and in such authorized denomination or denominations as the holder of such beneficial interest requests through instructions to the Registrar from or through the Depositary and the Participant or Indirect Participant. The Trustee shall deliver such Definitive Notes to the Persons in whose names such Notes are so registered.

     (d)  Transfer and Exchange of Definitive Notes for Beneficial Interests in Global Notes.

     A Holder of a Definitive Note may exchange such Note for a beneficial interest in a Global Note or transfer such Definitive Notes to a Person who takes delivery thereof in the form of a beneficial interest in a Global Note at any time. Upon receipt of a request for such an exchange or transfer, the Trustee shall cancel the applicable Definitive Note and increase or cause to be increased the aggregate principal amount of one of the Global Notes.

     If any such exchange or transfer from a Definitive Note to a beneficial interest is effected pursuant to the previous paragraph at a time when a Global Note has not yet been issued, the Company shall issue and, upon receipt of a Company Order in accordance with Section 2.02 hereof, the Trustee shall authenticate one or more Global Notes in an aggregate principal amount equal to the principal amount of Definitive Notes so transferred.

     A Holder of Definitive Notes may transfer such Notes to a Person who takes delivery thereof in the form of a Definitive Note.

     (e)  Transfer and Exchange of Definitive Notes for Definitive Notes. Upon request by a Holder of Definitive Notes and such Holder’s compliance with the provisions of this Section 2.04(e), the Registrar shall register the transfer or exchange of Definitive Notes. Prior to such registration of transfer or exchange, the requesting Holder must present or surrender to the Registrar the Definitive Notes duly endorsed or accompanied by a written instruction of transfer in form satisfactory to the Registrar duly executed by such Holder or by its attorney, duly authorized in writing. In addition, the requesting Holder must provide any additional certifications, documents and information, as applicable, required pursuant to the following provisions of this Section 2.04(e).

     (f)  Legends. A legend in substantially the following form will appear on the face of all Global Notes issued under this Supplemental Indenture unless specifically stated otherwise in the applicable provisions of this Supplemental Indenture.

“THIS GLOBAL NOTE IS HELD BY THE DEPOSITARY (AS DEFINED IN THE TWENTY-SECOND SUPPLEMENTAL INDENTURE GOVERNING THIS NOTE) OR ITS NOMINEE IN CUSTODY FOR THE BENEFIT OF THE BENEFICIAL OWNERS HEREOF, AND IS NOT TRANSFERABLE TO ANY PERSON UNDER ANY CIRCUMSTANCES EXCEPT THAT (1) THE TRUSTEE MAY MAKE SUCH NOTATIONS HEREON AS MAY BE REQUIRED PURSUANT TO SECTION 2.04 OF THE TWENTY-SECOND SUPPLEMENTAL INDENTURE, (2) THIS GLOBAL NOTE MAY BE EXCHANGED IN WHOLE BUT NOT IN PART PURSUANT TO SECTION 2.04(a) OF THE TWENTY-SECOND SUPPLEMENTAL INDENTURE, (3) THIS GLOBAL NOTE MAY BE DELIVERED TO THE TRUSTEE FOR CANCELLATION PURSUANT TO SECTION 2.12 OF THE BASE INDENTURE AND (4) THIS GLOBAL NOTE MAY BE TRANSFERRED TO A SUCCESSOR DEPOSITARY WITH THE PRIOR WRITTEN CONSENT OF NRG ENERGY, INC.

UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN DEFINITIVE FORM, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE

DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY. UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) (“DTC”), TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR SUCH OTHER ENTITY AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.”

     (g)  Cancellation and/or Adjustment of Global Notes. At such time as all beneficial interests in a particular Global Note have been exchanged for Definitive Notes or a particular Global Note has been redeemed, repurchased or canceled in whole and not in part, each such Global Note shall be returned to or retained and canceled by the Trustee in accordance with Section 2.12 of the Base Indenture. At any time prior to such cancellation, if any beneficial interest in a Global Note is exchanged for or transferred to a Person who will take delivery thereof in the form of a beneficial interest in another Global Note or for Definitive Notes, the principal amount of Notes represented by such Global Note will be reduced accordingly and a notation will be made on the records maintained by the Trustee or by the Depositary at the direction of the Trustee to reflect such reduction; and if the beneficial interest is being exchanged for or transferred to a Person who will take delivery thereof in the form of a beneficial interest in another Global Note, such other Global Note will be increased accordingly and a notation will be made on the records maintained by the Trustee or by the Depositary at the direction of the Trustee to reflect such increase.

     (h)  General Provisions Relating to Transfers and Exchanges.

     (1) To permit registrations of transfers and exchanges, the Company shall execute and the Trustee shall authenticate Global Notes and Definitive Notes upon receipt of a Company Order in accordance with Section 2.02 hereof or at the Registrar’s request.

     (2) No service charge shall be made to a Holder of a Global Note or to a Holder of a Definitive Note for any registration of transfer or exchange, but the Company may require payment of a sum sufficient to cover any transfer tax or similar governmental charge payable in connection therewith (other than any such transfer taxes or similar governmental charge payable upon exchange or transfer pursuant to Sections 3.06, 3.09, 4.10, 4.14 and 9.05 hereof and Section 2.11 of the Base Indenture).

     (3) The Registrar shall not be required to register the transfer of or exchange any Note selected for redemption in whole or in part, except the unredeemed portion of any Note being redeemed in part.

     (4) All Global Notes and Definitive Notes issued upon any registration of transfer or exchange of Global Notes or Definitive Notes shall be the valid obligations of the Company, evidencing the same debt, and entitled to the same benefits under this Supplemental Indenture, as the Global Notes or Definitive Notes surrendered upon such registration of transfer or exchange.

     (5) The Company shall not be required:

     (A) to issue, to register the transfer of or to exchange any Notes during a period beginning at the opening of business 15 days before the day of any selection of Notes for redemption under Section 3.02 hereof and ending at the close of business on the day of selection;

     (B) to register the transfer of or to exchange any Note selected for redemption in whole or in part, except the unredeemed portion of any Note being redeemed in part; or

     (C) to register the transfer of or to exchange a Note between a record date and the next succeeding interest payment date.

     (6) Prior to due presentment for the registration of a transfer of any Note, the Trustee, any Agent and the Company may deem and treat the Person in whose name any Note is registered as the absolute owner of such Note for the purpose of receiving payment of principal of and interest on such Notes and for all other purposes, and none of the Trustee, any Agent or the Company shall be affected by notice to the contrary.

     (7) The Trustee shall authenticate Global Notes and Definitive Notes in accordance with the provisions of Section 2.02 hereof.

     (8) All orders, certifications, certificates and Opinions of Counsel required to be submitted to the Registrar pursuant to this Section 2.04 to effect a registration of transfer or exchange may be submitted by facsimile.

     Section 2.05 Issuance of Additional Notes.

     The Company shall be entitled, upon delivery of an Officers’ Certificate, Opinion of Counsel and Company Order, subject to its compliance with Sections 4.09 hereof, to issue Additional Notes under this Supplemental Indenture which shall have identical terms as the Initial Notes issued on the Issue Date, other than with respect to the date of issuance and issue price. The Initial Notes issued on the Issue Date and any Additional Notes issued shall be treated as a single class for all purposes under this Supplemental Indenture.

     With respect to any Additional Notes, the Company shall set forth in a resolution of its Board of Directors and an Officers’ Certificate, a copy of each which shall be delivered to the Trustee, the following information:

     (a) the aggregate principal amount of such Additional Notes to be authenticated and delivered pursuant to this Supplemental Indenture; and

     (b) the issue price, the issue date and the CUSIP number of such Additional Notes.

ARTICLE 3.
REDEMPTION AND PREPAYMENT

     Section 3.01 Notices to Trustee.

     If the Company elects to redeem Notes pursuant to the optional redemption provisions of Section 3.07 hereof, it must furnish to the Trustee, at least 30 days (45 days in the case of a partial redemption) but not more than 60 days before a redemption date, an Officers’ Certificate setting forth:

     (1) the clause of this Supplemental Indenture pursuant to which the redemption shall occur;

     (2) the redemption date;

     (3) the principal amount of Notes to be redeemed; and

     (4) the redemption price.

     Section 3.02 Selection of Notes to Be Redeemed or Purchased.

     If less than all of the Notes are to be redeemed at any time, the Trustee shall select Notes for redemption on a pro rata basis among all outstanding Notes or, if the Notes are listed on any national securities exchange, in compliance with the requirements of the principal national securities exchange on which the Notes are listed, in either case, unless otherwise required by law.

     In the event of partial redemption by lot, the particular Notes to be redeemed or purchased shall be selected, unless otherwise provided herein, not less than 30 nor more than 60 days prior to the redemption by the Trustee from the outstanding Notes not previously called for redemption.

     The Trustee shall promptly notify the Company in writing of the Notes selected for redemption and, in the case of any Note selected for partial redemption, the principal amount thereof to be redeemed. Notes and portions of Notes selected shall be in amounts of $5,000 or whole multiples of $5,000 in excess of $5,000; except that if all of the Notes of a Holder are to be redeemed, the entire outstanding amount of Notes held by such Holder, even if not a multiple of $5,000, shall be redeemed. Except as provided in the preceding sentence, provisions of this Supplemental Indenture that apply to Notes called for redemption also apply to portions of Notes called for redemption.

     No Notes of $5,000 or less shall be redeemed in part. Notices of redemption shall be mailed by first class mail at least 30 but not more than 60 days before the redemption date to each Holder of Notes to be redeemed at its registered address, except that redemption notices may be mailed more than 60 days prior to a redemption date if the notice is issued in connection with a defeasance of the Notes or a satisfaction and discharge of this Supplemental Indenture.

     If any Note is to be redeemed in part only, the notice of redemption that relates to that Note shall state the portion of the principal amount of that Note that is to be redeemed. A new Note in principal amount equal to the unredeemed portion of the original Note shall be issued in the name of the Holder of notes upon cancellation of the original Note. Notes called for redemption become due on the date fixed for redemption. On and after the redemption date, interest ceases to accrue on notes or portions of them called for redemption.

     Section 3.03 Notice of Redemption.

     At least 30 days but not more than 60 days before a redemption date, the Company shall mail or cause to be mailed, by first class mail, a notice of redemption to each Holder whose Notes are to be redeemed at its registered address, except that redemption notice