Terraform Power, Inc. (TERP): Appaloosa Management Raises Stake and Steps Up Involvement

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION WASHINGTON,
D.C. 20549

_________________________

SCHEDULE
13D (Rule 13d-101)

INFORMATION
TO BE INCLUDED IN STATEMENTS FILED PURSUANT
TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO RULE
13d-2(a)

Under the Securities Exchange Act of 1934

(Amendment No.  4  )*

If
the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule
13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.
[   ]

Note: Schedules filed in paper format
shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom
copies are to be sent.

*The remainder of this cover page shall be
filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for
any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of
this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934
(“Exchange Act”) or otherwise subject to the liabilities of that section of the Exchange Act but shall be subject to
all other provisions of the Exchange Act (however, see the Notes).

⁽¹⁾ The percentage set forth in
Row 13 of this Cover Page is based on the 80,033,122 shares of Class A Common Stock (as defined herein) of the Issuer (as defined
herein) outstanding as of October 31, 2015, as reported in the Issuer’s Form 10-Q filed with the Securities and Exchange
Commission on November 9, 2015.

⁽¹⁾ The percentage set forth in
Row 13 of this Cover Page is based on the 80,033,122 shares of Class A Common Stock of the Issuer outstanding as of October 31,
2015, as reported in the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on November 9, 2015.

⁽¹⁾ The percentage set forth in
Row 13 of this Cover Page is based on the 80,033,122 shares of Class A Common Stock of the Issuer outstanding as of October 31,
2015, as reported in the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on November 9, 2015.

⁽¹⁾ The percentage set forth in
Row 13 of this Cover Page is based on the 80,033,122 shares of Class A Common Stock of the Issuer outstanding as of October 31,
2015, as reported in the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on November 9, 2015.

⁽¹⁾ The percentage set forth in
Row 13 of this Cover Page is based on the 80,033,122 shares of Class A Common Stock of the Issuer outstanding as of October 31,
2015, as reported in the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on November 9, 2015.

⁽¹⁾ The percentage set forth in
Row 13 of this Cover Page is based on the 80,033,122 shares of Class A Common Stock of the Issuer outstanding as of October 31,
2015, as reported in the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on November 9, 2015.

⁽¹⁾ The percentage set forth in
Row 13 of this Cover Page is based on the 80,033,122 shares of Class A Common Stock of the Issuer outstanding as of October 31,
2015, as reported in the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on November 9, 2015.

ITEM 3.     Source and Amount of Funds
or Other Consideration.

Item 3 of the prior Schedule 13D is hereby
amended and restated in its entirety to read as follows:

As of March 29, 2016: (i) AILP owns 3,724,799
shares of Class A Common Stock, representing approximately 4.65% of the issued and outstanding shares of Class A Common Stock
as of that date, which were acquired with the working capital of AILP; and (ii) Palomino Master owns 4,983,909 shares of Class
A Common Stock, representing approximately 6.23% of the issued and outstanding shares of Class A Common Stock as of that date,
which were acquired with the working capital of Palomino Master.

 ITEM 4.     Purpose
of the Transaction.

Item 4 of the prior Schedule 13D is hereby amended by adding the following after the sixth paragraph thereof:

In lieu of continuing
to press the Revised Demand, on January 12, 2016, AILP filed a shareholder derivative action on behalf of the Issuer against SUNE
and numerous individuals in the Delaware Court of Chancery alleging breach of fiduciary duty and related causes of action. Following
expedited discovery and preliminary injunction proceedings, on March 22, 2016, AILP filed an amended complaint in such action
(the “Amended Complaint”) under seal. The Amended Complaint seeks numerous corporate governance reforms, including (i)
removal of the current members of the Issuer’s Corporate Governance and Conflicts Committee and replacement with persons
elected by the Issuer’s public stockholders, (ii) removal of the Issuer’s chief executive officer, (iii) appointment
to the Board of a monitor or director to represent the interests of the Issuer’s public stockholders, and (iv) additional
related relief.  The litigation remains ongoing.  AILP may seek to further amend the Amended Complaint as the facts
develop, and also may seek further changes to the Issuer’s corporate governance and management.

ITEM 5.     Interest in Securities of
the Issuer.

Subparagraph (c) of Item 5 of the prior Schedule 13D is hereby amended and restated in its entirety to read as follows:

(c) Information concerning transactions
in the Class A Common Stock effected by the Reporting Persons since January 8, 2016 is set forth in Schedule 1 hereto and is incorporated
herein by reference.

ITEM 7.     Materials
to be Filed as Exhibits.

Item 7 is hereby amended to add the following exhibits:

SIGNATURES

After reasonable inquiry and to the best of
my knowledge and belief, the undersigned certifies that the information set forth in this statement is true, complete and correct.

SCHEDULE 1

Transactions
of the Reporting Persons Effected from January 8, 2016
through and including March 29, 2016