UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): June 12, 2018

NRG Yield, Inc.

(Exact name of Registrant as specified in its charter)

804 Carnegie Center, Princeton, New Jersey 08540

(Address of principal executive offices, including zip code)

(609) 524-4500

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o  Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o  Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company     o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Item 1.01 Entry Into a Material Definitive Agreement.

Sixth Supplemental Indenture

On June 12, 2018, NRG Yield Operating LLC (“Yield Operating”), a subsidiary of NRG Yield LLC (“NYLD LLC”), the guarantors currently party to the 2024 Notes Indenture (defined below), Thermal Infrastructure Development Holdings LLC (the “Guaranteeing Subsidiary”) and Delaware Trust Company (as successor in interest to Law Debenture Trust Company of New York), as trustee (the “Trustee”), entered into the sixth supplemental indenture (the “Sixth Supplemental Indenture”), supplementing the indenture, dated as of August 5, 2014 (as amended or supplemented to the date hereof, the “2024 Notes Indenture”), by and among Yield Operating, the guarantors party thereto and the Trustee, pursuant to which Yield Operating issued $500,000,000 in aggregate principal amount of its 5.375% Senior Notes due 2024 (the “2024 Notes”).  Pursuant to the Sixth Supplemental Indenture, the Guaranteeing Subsidiary became a guarantor of Yield Operating’s obligations under the 2024 Notes. Each of Yield Operating, NYLD LLC and the Guaranteeing Subsidiary are subsidiaries of NRG Yield, Inc.

The foregoing description of the Sixth Supplemental Indenture does not purport to be complete and is qualified in its entirety by reference to the Sixth Supplemental Indenture, which is attached as Exhibit 4.1 to this Current Report on Form 8-K and is incorporated by reference herein.

Second Supplemental Indenture

On June 12, 2018, Yield Operating, the guarantors currently party to the 2026 Notes Indenture (defined below), the Guaranteeing Subsidiary and the Trustee also entered into the second supplemental indenture (the “Second Supplemental Indenture”), supplementing the indenture, dated as of August 18, 2016 (the “2026 Notes Indenture”), by and among Yield Operating, the guarantors party thereto and the Trustee, pursuant to which Yield Operating issued $350,000,000 in aggregate principal amount of its 5.000% Senior Notes due 2026 (the “2026 Notes”).  Pursuant to the Second Supplemental Indenture, the Guaranteeing Subsidiary became a guarantor of Yield Operating’s obligations under the 2026 Notes.

The foregoing description of the Second Supplemental Indenture does not purport to be complete and is qualified in its entirety by reference to the Second Supplemental Indenture, which is attached as Exhibit 4.2 to this Current Report on Form 8-K and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits

(d)                                 Exhibits

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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Exhibit 4.1

Execution Version

SIXTH SUPPLEMENTAL INDENTURE

SIXTH SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as of June 12, 2018, among Thermal Infrastructure Development Holdings LLC (the “Guaranteeing Subsidiary”), a subsidiary of NRG Yield Operating LLC (or its permitted successor), a Delaware limited liability company (the “Company”), the Company, the other Guarantors (as defined in the Indenture referred to herein) and Delaware Trust Company (as successor in interest to Law Debenture Trust Company of New York), as trustee under the Indenture 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 “Indenture”), dated as of August 5, 2014 providing for the issuance of 5.375% Senior Notes due 2024 (the “Notes”);

WHEREAS, the Indenture provides that under certain circumstances the Guaranteeing Subsidiary shall execute and deliver to the Trustee a supplemental indenture pursuant to which the Guaranteeing Subsidiary shall fully and 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 Indenture, the Trustee, the Company and the other Guarantors are authorized to execute and deliver this Supplemental Indenture.

NOW, THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt of which is hereby acknowledged, the 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 Indenture.

2.                                      AGREEMENT TO GUARANTEE. The Guaranteeing Subsidiary hereby becomes party to the Indenture as a Guarantor and as such will have all the rights and be subject to all the Obligations and agreements of Guarantors under the Indenture. The Guaranteeing Subsidiary hereby agrees to provide a full and unconditional Guarantee on the terms and subject to the conditions set forth in the Subsidiary Guarantee and in the 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, this 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 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.  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 or for or in respect of the recitals contained herein, all of which recitals are made solely by the Guaranteeing Subsidiary 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.

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

[Signature Page to Sixth Supplemental Indenture]

[Signature Page to Sixth Supplemental Indenture]

Exhibit 4.2

Execution Version

SECOND SUPPLEMENTAL INDENTURE

SECOND SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as of June 12, 2018, among Thermal Infrastructure Development Holdings LLC (the “Guaranteeing Subsidiary”), a subsidiary of NRG Yield Operating LLC (or its permitted successor), a Delaware limited liability company (the “Company”), the Company, the other Guarantors (as defined in the Indenture referred to herein) and Delaware Trust Company (as successor in interest to Law Debenture Trust Company of New York), as trustee under the Indenture 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 “Indenture”), dated as of August 18, 2016 providing for the issuance of 5.000% Senior Notes due 2026 (the “Notes”);

WHEREAS, the Indenture provides that under certain circumstances the Guaranteeing Subsidiary shall execute and deliver to the Trustee a supplemental indenture pursuant to which the Guaranteeing Subsidiary shall fully and 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 Indenture, the Trustee, the Company and the other Guarantors are authorized to execute and deliver this Supplemental Indenture.

NOW, THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt of which is hereby acknowledged, the 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 Indenture.

2.                                      AGREEMENT TO GUARANTEE. The Guaranteeing Subsidiary hereby becomes party to the Indenture as a Guarantor and as such will have all the rights and be subject to all the Obligations and agreements of Guarantors under the Indenture. The Guaranteeing Subsidiary hereby agrees to provide a full and unconditional Guarantee on the terms and subject to the conditions set forth in the Subsidiary Guarantee and in the 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, this 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 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.  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 or for or in respect of the recitals contained herein, all of which recitals are made solely by the Guaranteeing Subsidiary 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.

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

[Signature Page to Second Supplemental Indenture]

[Signature Page to Second Supplemental Indenture]