Exhibit 99.23

JOINDER AGREEMENT

This Joinder Agreement, dated as of June 29, 2018, (this “Joinder Agreement”) is a joinder to the Governance Agreement, dated October 6, 2017, by and among TerraForm Power, Inc. (the “Company”), Orion US Holdings 1 L.P. (“Sponsor”) and the other parties party thereto from time to time (as supplemented by the joinder, dated June 11, 2018, by and among the Company, Sponsor and Brookfield BRP Holdings (Canada) Inc., the “Governance Agreement”). Capitalized terms used but not defined herein shall have the meaning given to such terms in the Governance Agreement.

1. The undersigned, having received and reviewed a copy of the Governance Agreement, hereby agrees to be bound by the terms, conditions and other provisions of the Governance Agreement as though it is a “Sponsor Party” under the Governance Agreement, with all attendant rights, duties and obligations stated therein applicable to the “Sponsor Parties” in the same manner as if the undersigned were party to the Governance Agreement as of the date on which it was originally executed.

2. The undersigned represents and warrants to the Company that it is a Controlled Affiliate of Brookfield.

3. This Joinder Agreement shall be deemed to be made in and in all respects shall be interpreted, governed by and construed in accordance with, the internal laws of the State of Delaware, 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.

4. This Joinder Agreement may be executed in any number of counterparts and by the parties hereto on separate counterparts, each of which shall be deemed an original, but all the counterparts shall together constitute one and the same instrument. This Joinder Agreement and any signed agreement or instrument entered into in connection with this Joinder Agreement, and any amendments or waivers hereto and thereto, to the extent signed and delivered by facsimile or in electronic format (e.g., “pdf” or “tif”) shall be treated in all manner and respects as an original agreement or instrument and shall be considered to have the same binding legal effect as if it were the original signed version thereof delivered in person.

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IN WITNESS WHEREOF, each of the undersigned has executed and delivered this Joinder Agreement as of the date first written above.

	BBHC ORION HOLDCO L.P. By its general partner ORION CANADIAN AIV GP INC.


	By:	/s/ Douglas Christie
		Name: Douglas Christie
		Title: Senior Vice President

	By:	/s/ Adrienne Moore
		Name: Adrienne Moore
		Title: Vice President

AGREED AND ACKNOWLEDGED:

TERRAFORM POWER, INC.,


By:	/s/ Andrea Rocheleau
	Name: Andrea Rocheleau
	Title: General Counsel

ORION US HOLDINGS 1 L.P., by its general partner,ORION US GP LLC


By:	/s/ Julian Deschatelets
	Name: Julian Deschatelets
	Title: Senior Vice President

BROOKFIELD BRP HOLDINGS (CANADA) INC.


By:	/s/ Jennifer Mazin
	Name: Jennifer Mazin
	Title: Senior Vice President and Secretary