SIXTY-FIFTH SUPPLEMENTAL INDENTURE FOR ADDITIONAL SUBSIDIARY GUARANTEES

Exhibit 4.2

SIXTY-FIFTH SUPPLEMENTAL INDENTURE FOR

ADDITIONAL SUBSIDIARY GUARANTEES

SIXTY-FIFTH SUPPLEMENTAL INDENTURE (this “Supplemental Indenture for Additional Guarantees”), dated as of May 9, 2012, among Green Mountain Energy Company (NY COM) LLC and Green Mountain Energy Company (NY RES) LLC (each, a “Guaranteeing Subsidiary” and together, the “Guaranteeing Subsidiaries”), each a subsidiary of NRG Energy, Inc., a Delaware corporation (the “Company”), the Company, the Existing Guarantors set forth on the signature pages hereto (the “Existing Guarantors”) and Law Debenture Trust Company of New York, as trustee under the indentures referred to below (the “Trustee”).

W I T N E S S E T H

WHEREAS, the Company has heretofore executed and delivered to the Trustee an indenture (the “Base Indenture”), dated as of February 2, 2006, between the Company and the Trustee, as amended by a Twenty-Second Supplemental Indenture (the “Twenty-Second Supplemental Indenture”), dated as of June 5, 2009, among the Company, the Guarantors named therein and the Trustee, providing for the original issuance of an aggregate principal amount of $700 million of 8.50% Senior Notes due 2019 (the “Initial Notes”), and, subject to the terms of the Twenty-Second Supplemental Indenture, future unlimited issuances of 8.50% Senior Notes due 2019 (the “Additional Notes,” and together with the Initial Notes, the “Notes”), a twenty-third supplemental indenture, dated as of July 14, 2009, among the Company, the Existing Guarantors party thereto and the Trustee (the “Twenty-Third Supplemental Indenture”), a twenty-seventh supplemental indenture, dated as of October 5, 2009, among the Company, the Existing Guarantors party thereto and the Trustee (the “Twenty-Seventh Supplemental Indenture”), a thirty-first supplemental indenture, dated as of April 16, 2010, among the Company, the Existing Guarantors party thereto and the Trustee (the “Thirty-First Supplemental Indenture”), a thirty-fifth supplemental indenture, dated as of June 23, 2010, among the Company, the Existing Guarantors party thereto and the Trustee (the “Thirty-Fifth Supplemental Indenture”), a fortieth supplemental indenture, dated as of December 15, 2010, among the Company, the Existing Guarantors party thereto and the Trustee (the “Fortieth Supplemental Indenture”), a forty-seventh supplemental indenture, dated as of May 20, 2011, among the Company, the Existing Guarantors party thereto and the Trustee (the “Forty-Seventh Supplemental Indenture”), a fifty-third supplemental indenture, dated as of November 8, 2011, among the Company, the Existing Guarantors party thereto and the Trustee (the “Fifty-Third Supplemental Indenture”), and a fifty-ninth supplemental indenture, dated as of April 5, 2012, among the Company, the Existing Guarantors and the Trustee (the “Fifty-Ninth Supplemental Indenture” and together with the Base Indenture, the Twenty-Second Supplemental Indenture, the Twenty-Third Supplemental Indenture, the Twenty-Seventh Supplemental Indenture, the Thirty-First Supplemental Indenture, the Thirty-Fifth Supplemental Indenture, the Fortieth Supplemental Indenture, the Forty-Seventh Supplemental Indenture and the Fifty-Third Supplemental Indenture, the “Indenture”);

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 (the “Additional Guarantees”); and

WHEREAS, pursuant to Section 4.17 of the Twenty-Second Supplemental Indenture, the Trustee, the Company and the Existing Guarantors are authorized and required to execute and deliver this Supplemental Indenture for Additional Guarantees.

NOW THEREFORE, in consideration of the foregoing and for good and valuable consideration, the receipt of which is hereby acknowledged, the Guaranteeing Subsidiaries, the Trustee, the Company

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and the Existing Guarantors mutually covenant and agree for the equal and ratable benefit of the Holders of the Notes as follows:

1.             Capitalized Terms. Unless otherwise defined in this Supplemental Indenture for Additional Guarantees, capitalized terms used herein without definition shall have the meanings assigned to them in the Indenture.

2.             Agreement to Be Bound; Guarantee. The Guaranteeing Subsidiaries hereby become parties to the Indenture as Guarantors and as such will have all of the rights and be subject to all of the Obligations and agreements of a Guarantor under the Indenture. The Guaranteeing Subsidiaries hereby agree to be bound by all of the provisions of the Indenture applicable to a Guarantor and to perform all of the Obligations and agreements of a Guarantor under the Indenture.  In furtherance of the foregoing, the Guaranteeing Subsidiaries shall be deemed Guarantors for purposes of Article 10 of the Twenty-Second Supplemental Indenture, including, without limitation, Section 10.02 thereof.

3.             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.