Exhibit 3.01(a)

State of Delaware

Secretary of State

Division of Corporations

Delivered 12:53 PM 03/05/2013

FILED 12:26 PM 03/05/2013

SRV 130275925 - 5271506 FILE

CERTIFICATE OF FORMATION

OF

NRG YIELDCO OPERATING LLC

*        *        *        *

Adopted in accordance with the provisions of §18-101

of the Limited Liability Company Act

of the State of Delaware

*        *        *        *

The undersigned, being duly authorized to execute and file this Certificate of Formation for the purpose of forming a limited liability company pursuant to the Delaware Limited Liability Company Act, 6 Del. C. Section 18-101, et seq., does hereby certify as follows:

FIRST

The name of the limited liability company is NRG Yieldco Operating LLC (the “Company”).

SECOND

The address of the registered office in the State of Delaware is 1209 Orange Street, City of Wilmington, New Castle County, Delaware 19801. The name of the registered agent at such address is The Corporation Trust Company.

IN WITNESS WHEREOF, the undersigned has duly executed this Certificate of Formation as of the 5th day of March, 2013.

/s/ Cindy Oberdorff

Name: Cindy Oberdorff

Title: Authorized Person