Sec Form 4 Filing - BlueMountain Capital Management, LLC @ TerraForm Power, Inc. - 2016-05-13

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person BlueMountain Capital Management, LLC 2. Issuer Name and Ticker or Trading Symbol TerraForm Power, Inc. [ TERP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 280 PARK AVENUE, 12TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 05/13/2016 (Street) NEW YORK, NY10017 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 50,000 D $ 8.78 9,119,934 I Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 44,042 D $ 8.78 8,033,248 I Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 35,479 D $ 8.78 6,471,200 I Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 35,479 D $ 8.78 6,471,200 D Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 3,689 D $ 8.78 672,929 I Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 3,689 D $ 8.78 672,929 D Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 1,398 D $ 8.78 255,029 I Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 1,398 D $ 8.78 255,029 D Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 2,471 D $ 8.78 450,721 I Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 2,471 D $ 8.78 450,721 D Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 4,060 D $ 8.78 740,502 I Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 4,060 D $ 8.78 740,502 D Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 1,005 D $ 8.78 183,369 I Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 1,005 D $ 8.78 183,369 D Class A Common Stock ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) 05/13/2016 S 1,898 D $ 8.78 346,184 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Da te Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other BlueMountain Capital Management, LLC 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X BlueMountain GP Holdings, LLC 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X Blue Mountain CA Master Fund GP, Ltd. 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X Blue Mountain Credit Alternatives Master Fund L.P. 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X BLUEMOUNTAIN FOINAVEN GP, LLC 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X BLUEMOUNTAIN FOINAVEN MASTER FUND L.P. 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X BlueMountain Long/Short Credit GP, LLC 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X BlueMountain Guadalupe Peak Fund L.P. 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X BLUEMOUNTAIN LOGAN OPPORTUNITIES GP, LLC 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X BLUEMOUNTAIN LOGAN OPPORTUNITIES MASTER FUND L.P. 280 PARK AVENUE, 12TH FLOOR NEW YORK, NY10017 X Signatures BlueMountain Capital Management, LLC, By: /s/ Eric M. Albert, Chief Compliance Officer 05/17/2016 Signature of Reporting Person Date BlueMountain GP Holdings, LLC, By: /s/ Eric M. Albert, Chief Compliance Officer 05/17/2016 Signature of Reporting Person Date Blue Mountain CA Master Fund GP, Ltd., By: /s/ Andrew Feldstein, Director 05/17/2016 Signature of Reporting Person Date Blue Mountain Credit Alternatives Master Fund L.P., By: BlueMountain CA Master Fund GP, Ltd., By: /s/ Andrew Feldstein, Director 05/17/2016 Signature of Reporting Person Date BlueMountain Foinaven GP, LLC, By: BlueMountain GP Holdings, LLC, By: /s/ Eric M. Albert, Chief Compliance Officer 05/17/2016 Signature of Reporting Person Date BlueMountain Foinaven Master Fund L.P., By: BlueMountain Foinaven GP, LLC, By: BlueMountain GP Holdings, LLC, By: /s/ Eric M. Albert, Chief Compliance Officer 05/17/2016 Signature of Reporting Person Date BlueMountain Long/Short Credit GP, LLC, By: BlueMountain GP Holdings, LLC, By: /s/ Eric M. Albert, Chief Compliance Officer 05/17/2016 Signature of Reporting Person Date BlueMountain Guadalupe Peak Fund L.P., By: BlueMountain Long/Short Credit GP, LLC, By: BlueMountain GP Holdings, LLC, By: /s/ Eric M. Albert, Chief Compliance Officer 05/17/2016 Signature of Reporting Person Date BlueMountain Logan Opportunities GP, LLC, By: BlueMountain GP Holdings, LLC, By: /s/ Eric M. Albert, Chief Compliance Officer 05/17/2016 Signature of Reporting Person Date BlueMountain Logan Opportunities Master Fund L.P., By: BlueMountain Logan Opportunities GP, LLC, By: BlueMountain GP Holdings, LLC, By: /s/ Eric M. Albert, Chief Compliance Officer 05/17/2016 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The filing of this Form 4 shall not be construed as an admission that any of BlueMountain Capital Management, LLC ("BMCM"), GP Holdings (as defined in Footnote 5) or the General Partners (as defined in Footnote 5) is or was for the purposes of Section 16(a) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise the beneficial owner of any of the shares of Class A Common Stock, par value $0.01 per share (the "Common Stock"), of Terraform Power, Inc. (the "Issuer"). Pursuant to Rule 16a-1(a)(4) of the Exchange Act, each of BMCM, GP Holdings and the General Partners disclaims such beneficial ownership, except to the extent of its respective pecuniary interest. ( 2 )BMCM is the investment manager of each of: (i) Blue Mountain Credit Alternatives Master Fund L.P. ("BMCA"), which is the beneficial owner of 6,471,200 shares of Common Stock; (ii) BlueMountain Foinaven Master Fund L.P. ("BMFV"), which is the beneficial owner of 672,929 shares of Common Stock; (iii) BlueMountain Guadalupe Peak Fund L.P. ("BMGP"), which is the beneficial owner of 255,029 shares of Common Stock; (iv) BlueMountain Logan Opportunities Master Fund L.P. ("BMLO"), which is the beneficial owner of 450,721 shares of Common Stock; (v) BlueMountain Montenvers Fund SCA SICAV-SIF ("BMM"), which is the beneficial owner of 740,502 shares of Common Sto ck; (vi) BlueMountain Kicking Horse Fund L.P. ("BMKH" and, together with BMCA, BMFV, BMGP and BMLO, the "Partnerships"), which is the beneficial owner of 183,369 shares of Common Stock; and ( 3 )(vii) BlueMountain Timberline Ltd. ("BMT" and, together with the Partnerships and BMM, the "Funds"), which is the beneficial owner of 346,184 shares of Common Stock. BMCM, although it directs the voting and disposition of the Common Stock held by the Funds, only receives an asset-based fee relating to the Common Stock held by the Funds. ( 4 )(i) Blue Mountain CA Master Fund GP, Ltd. ("BMCA GP") is the general partner of BMCA and has an indirect profits interest in the Common Stock beneficially owned by it; (ii) BlueMountain Foinaven GP, LLC ("BMFV GP") is the general partner of BMFV and has an indirect profits interest in the Common Stock beneficially owned by it; (iii) BlueMountain Long/Short Credit GP, LLC ("BMGP GP") is the general partner of BMGP and has an indirect profits interest in the Common Stock beneficially owned by it; (iv) BlueMountain Montenvers GP S.a r.l. ("BMM GP") is the general partner of BMM and has an indirect profits interest in the Common Stock beneficially owned by it; (v) BlueMountain Logan Opportunities GP, LLC ("BMLO GP") is the general partner of BMLO and has an indirect profits interest in the Common Stock beneficially owned by it; and ( 5 )(vi) BlueMountain Kicking Horse Fund GP, LLC ("BMKH GP" and, together with BMCA GP, BMFV GP, BMGP GP and BMLO GP, the "General Partners") is the general partner of BMKH and has an indirect profits interest in the Common Stock beneficially owned by it. BlueMountain GP Holdings, LLC ("GP Holdings") is the sole owner of each of the General Partners and thus has an indirect profits interest in the Common Stock beneficially owned by the Partnerships. BMCM is the sole owner of BMM GP and thus has an indirect profits interest in the Common Stock beneficially owned by BMM. ( 6 )On May 13, 2016: (i) BMCA sold 35,479 shares of Common Stock; (ii) BMFV sold 3,689 shares of Common Stock; (iii) BMGP sold 1,398 shares of Common Stock; (iv) BMLO sold 2,471 shares of Common Stock; (v) BMM sold 4,060 shares of Common Stock; (vi) BMKH sold 1,005 shares of Common Stock; and (vii) BMT sold 1,898 shares of Common Stock. ( 7 )The Reporting Persons are jointly filing this Form 4 pursuant to Rule 16(a)-3(j) under the Exchange Act. The Form 4 for certain additional Reporting Persons is being filed separately and simultaneously with this Form 4 due to the limitation of ten Reporting Persons per filing.

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