Supplemental Indenture (Additional Subsidiary Guarantees-3.750% Senior Secured First Lien Notes due 2024 and 4.450% Senior Secured First Lien Notes due 2029) dated February 17, 2022, among NRG Energy, Inc., each of its guarantor subsidiaries, and Delaware Trust Company as trustee

SUPPLEMENTAL INDENTURE (this “Supplemental Indenture for Additional Guarantees”), dated as of February 17, 2022, among each of the signatories hereto (each, a “Guaranteeing Subsidiary”), each a subsidiary of NRG Energy, Inc. (or its permitted successor), a Delaware corporation (the “Company”), the Company, the other Guarantors (as defined in the Indenture referred to herein) and Delaware Trust Company, as trustee under the Indenture referred to below (the “Trustee”).

WHEREAS, the Company has heretofore executed and delivered to the Trustee an indenture (the “Base Indenture”), dated as of May 28, 2019, between the Company and the Trustee, as amended by a Supplemental Indenture (the “Supplemental Indenture” and, together with the Base Indenture, the “Indenture”), dated as of May 28, 2019, among the Company, the Guarantors named therein and the Trustee, providing for the original issuance of an aggregate principal amount of $600,000,000 of 3.750% Senior Secured First Lien Notes due 2024 (the “2024 Notes”) and $500,000,000 of 4.450% Senior Secured First Lien Notes due 2029 (the “2029 Notes” and, together with the 2024 Notes, the “Initial Notes”), and, subject to the terms of the Supplemental Indenture, future issuances of 2024 Notes and/or 2029 Notes (the “Additional Notes,” and, together with the Initial Notes, the “Notes”);

WHEREAS, the Indenture provides that under certain circumstances the Guaranteeing Subsidiaries shall execute and deliver to the Trustee a supplemental indenture pursuant to which the Guaranteeing Subsidiaries shall unconditionally guarantee all of the Company’s Obligations under the Notes and the Indenture on the terms and conditions set forth herein (the “Subsidiary Guarantee”); and

WHEREAS, pursuant to Sections 4.10 and 9.01 of the Supplemental Indenture, the Trustee, the Company and the other Guarantors are authorized to execute and deliver this Supplemental Indenture for Additional Guarantees.

NOW, THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt of which is hereby acknowledged, each Guaranteeing Subsidiary and the Trustee mutually covenant and agree for the equal and ratable benefit of the Holders of the Notes as follows:

1.CAPITALIZED TERMS. Capitalized terms used herein without definition shall have the meanings assigned to them in the Supplemental Indenture.

2.AGREEMENT TO GUARANTEE. Each Guaranteeing Subsidiary hereby becomes a party to the Supplemental Indenture as a Guarantor and as such will have all the rights and be subject to all the Obligations and agreements of a Guarantor under the Indenture. Each Guaranteeing Subsidiary hereby agrees to provide an unconditional Guarantee on the terms and subject to the conditions set forth in the Subsidiary Guarantee and in the Supplemental Indenture including but not limited to Article 10 thereof.

3.NO RECOURSE AGAINST OTHERS. No director, officer, employee, incorporator or stockholder of the Company or any Guarantor, as such, will have any liability for any obligations of the Company or the Guarantors under the Notes, the Indenture, the Subsidiary

Guarantees or for any claim based on, in respect of, or by reason of, such obligations or their creation. Each Holder of Notes by accepting a Note waives and releases all such liability. The waiver and release are part of the consideration for issuance of the Notes. The waiver may not be effective to waive liabilities under the federal securities laws.

4.NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF NEW YORK SHALL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE FOR ADDITIONAL GUARANTEES BUT WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

5.COUNTERPARTS. The parties may sign any number of copies of this Supplemental Indenture for Additional Guarantees. Each signed copy shall be an original, but all of them together represent the same agreement.

6.EFFECT OF HEADINGS. The Section headings herein are for convenience only and shall not affect the construction hereof.

7.THE TRUSTEE. The Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this Supplemental Indenture for Additional Guarantees or for or in respect of the recitals contained herein, all of which recitals are made solely by the Guaranteeing Subsidiaries and the Company.

8.RATIFICATION OF INDENTURE; SUPPLEMENTAL INDENTURE FOR ADDITIONAL GUARANTEES PART OF INDENTURE. Except as expressly amended hereby, the Indenture is in all respects ratified and confirmed and all the terms, conditions and provisions thereof shall remain in full force and effect. This Supplemental Indenture for Additional Guarantees shall form a part of the Indenture for all purposes, and every Holder of Notes heretofore or hereafter authenticated and delivered shall by bound hereby.

9.ELECTRONIC SIGNATURES. Each of the transaction parties agrees on behalf of itself, and any Person acting or claiming by, under or through such transaction party, that any written instrument delivered in connection with this Supplemental Indenture for Additional Guarantees, the Indenture or any related document, including without limitation any amendments or supplements to such documents, may be executed by electronic methods (whether by .pdf scan or utilization of an electronic signature platform or application). Any electronic signature document delivered via email from a person authorized on an incumbency certificate provided by the Company, any Guaranteeing Subsidiary or any other Guarantor to the Trustee shall be considered signed or executed by such person on behalf of the Company, such Guaranteeing Subsidiary, or such other Guarantor, as applicable. Each of the Company, the Guaranteeing Subsidiaries, and the other Guarantors agree to assume all risks arising out of the use of electronic methods for all purposes including the authorization, execution, delivery, or submission of documents, instruments, notices, directions, instructions, reports, opinions and certificates to the Trustee, including without limitation the risk of the Trustee acting on unauthorized instructions, and the risk of interception and misuse by third parties. Any electronic signature shall have the same legal validity and enforceability as a manually executed signature to the fullest extent permitted by applicable law, including the Federal Electronic Signatures in Global and National Commerce Act, the New York State Electronic Signatures and Records Act, or any similar federal or state law, rule or regulation, as the same may be in effect from time to time, and the parties hereby waive any objection to the contrary. Any document accepted, executed or agreed to in conformity with such laws will be binding on all parties hereto to the same extent as if it were physically executed and each party hereby consents to the use of any

third party electronic signature capture service providers as may be reasonably chosen by a signatory hereto.

IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture for Additional Guarantees to be duly executed and attested, all as of the date first above written.

By: /s/ Gaëtan C. Frotté     

Name: Gaëtan C. Frotté

Title: Treasurer

By: /s/ Gaëtan C. Frotté     

Name: Gaëtan C. Frotté

Title: Treasurer

By: /s/ Gaëtan C. Frotté     

Name: Gaëtan C. Frotté

Title: Treasurer

By: /s/ Gaëtan C. Frotté     

Name: Gaëtan C. Frotté

Title: Treasurer

By: /s/ Gaëtan C. Frotté     

Name: Gaëtan C. Frotté

Title: Vice President

By: /s/ Thomas A. Smith     

Name: Thomas A. Smith

Title: Vice President

By: /s/ Linda Weigand     

Name: Linda Weigand

Title: Treasurer

By: /s/ Gaëtan C. Frotté     

Name: Gaëtan C. Frotté

Title: Treasurer

By: NRG Rockford Acquisition LLC, its General Partner

By:    /s/Gaëtan C. Frotté_________________________

Name:    Gaëtan C. Frotté

Title: Treasurer    

By: Texas Genco GP, LLC, its General Partner

By:    /s/Gaëtan C. Frotté_________________________

    Name:    Gaëtan C. Frotté

    Title: Treasurer

By: New Genco GP, LLC, its General Partner

By:    /s/Gaëtan C. Frotté_________________________

    Name:    Gaëtan C. Frotté

    Title: Treasurer    

By: STREAM SPE GP, LLC, the sole general partner

By: /s/ Gaëtan C. Frotté________________________

    Name:    Gaëtan C. Frotté

    Title: Treasurer    

By: /s/ Gaëtan C. Frotté____________________________

Name: Gaëtan C. Frotté

Title: Vice President & Treasurer

By: XOOM ENERGY, LLC, the sole member

By: /s/ Gaëtan C. Frotté_________________________

Name: Gaëtan C. Frotté

Title: Treasurer