Exhibit 10.28


 


JOINDER AGREEMENT AND AMENDMENT TO SUBORDINATION
AND


INTERCREDITOR AGREEMENT





 


This JOINDER AGREEMENT AND
AMENDMENT TO SUBORDINATION AND INTERCREDITOR AGREEMENT dated as of December 22, 2020 (this "Agreement"), is executed
by FLEX LEASING POWER AND SERVICE ULC, an Alberta unlimited liability corporation (the "New Subsidiary"), in favor
of TEXAS CAPITAL BANK, NATIONAL ASSOCIATION, in its capacity as Agent ("Agent"), and acknowledged and accepted
by Agent, the existing Loan Parties and the Subordinated Lenders, as defined in and pursuant to, that certain Subordination and Intercreditor
Agreement dated as of February 8, 2019 (as amended, restated, supplemented or otherwise modified from time to time, the "Intercreditor
Agreement"), among Agent, the Subordinated Lenders from time to time party thereto, FlexEnergy Power Solutions, LLC, a Delaware
limited liability company, as Parent, Flex Leasing Power & Service LLC, a Delaware limited liability company, as Company, and
each of the other Loan Parties from time to time party thereto. All capitalized terms used herein and not otherwise defined shall have
the meanings set forth in the Intercreditor Agreement.





 


Section 1. Amendment
to Intercreditor Agreement.





 


Section 1 of the Intercreditor
Agreement is hereby amended by amending and replacing the definition of "Loan Parties" in its entirety to read as follows:





 


"Loan Parties"
shall mean the Company and each Subsidiary of the Company that is now or hereafter becomes a party to any Senior Debt Document. All references
in this Agreement to any Loan Party shall include such Loan Party as a debtor-in-possession and any receiver or trustee for such Loan
Party in any Proceeding.





 


Section 2. Joinder
to Intercreditor Agreement.





 


(a)          The
New Subsidiary, for the benefit of Agent, hereby agrees as follows: The New Subsidiary hereby acknowledges the Intercreditor Agreement
and acknowledges, agrees and confirms that, by its execution of this Agreement, the New Subsidiary will be deemed to be a "Loan
Party" under the Intercreditor Agreement and shall have all of the obligations of a Loan Party thereunder as if it had executed
the Intercreditor Agreement. The New Subsidiary hereby ratifies, as of the date hereof, and agrees to be bound by, all of the terms,
provisions and conditions contained in the Intercreditor Agreement.





 


(b)          The
address of the New Subsidiary for purposes of Section 13 of the Intercreditor Agreement is as follows:


 





6400 S. Fiddlers Green Circle, Suite 900,








Greenwood Village, CO 80111


Attention:     Doug Baltzer





Fax:               (303)
694-0344





E-Mail:          doug.baltzer@flexleasingpower.com


 





Section 3. Miscellaneous.


 





(a)          Continuing
Effect. Except as specifically provided herein, each party hereto confirms and agrees that the Intercreditor Agreement shall remain in
full force and effect in accordance with its terms and is hereby ratified and confirmed in all respects.


 






     


     


    




 


(b)          Governing
Law. THIS AGREEMENT AND THE RIGHTS AND OBLIGATIONS OF THE NEW SUBSIDIARY HEREUNDER SHALL BE GOVERNED BY AND CONSTRUED AND INTERPRETED
IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS.





 


(c)         Severability.
Any provision of this Agreement that is prohibited or unenforceable in any jurisdiction shall not invalidate the remaining provisions
hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in
any other jurisdiction.





 


(d)         Counterparts.
This Agreement may be executed in any number of counterparts, each of which counterparts when executed and delivered shall be an original,
but all of which shall together constitute one and the same instrument. Delivery of an executed counterpart of this Agreement by fax or
other electronic transmission shall be equally effective as delivery of a manually executed counterpart.


 





(e)           Headings.
Section headings in this Agreement are included herein for convenience of reference only and shall not constitute a part of this
Agreement for any other purpose.


 





(f)            Binding
Effect; Assignment. This Agreement shall be binding upon and inure to the benefit of the Agent, the Senior Secured Parties and the Subordinated
Lenders and their respective successors and assigns.


 





(g)          Entire
Agreement. This Agreement constitutes the entire agreement and understanding among the parties hereto with respect to the subject matter
hereof and supersedes any prior agreements, written or oral, with respect thereto.


 


[Signature Pages Follow]


 





[Signature
Page to Joinder and Amendment to Subordination and Intercreditor Agreement]


 






     


     


    







 


IN WITNESS WHEREOF, the New
Subsidiary has caused this Agreement to be duly executed by its authorized officer, as of the day and year first above written.





 


	 	FLEX LEASING POWER AND SERVICE ULC, an Alberta unlimited liability
    company








 


	 	By:	 




	 	Name:	 




	 	Title:	 




 


[Signature
Page to Joinder and Amendment to Subordination and Intercreditor Agreement]


 



     


     


    













 


	 	ACKNOWLEDGED AND AGREED TO BY:







 


	 	SUBORDINATED LENDERS:




 


	 	RNS FLEX, LLC




 


	 	By: RNS Management, LLC, its Manager




 


	 	By:	 







	 	 	Name:




	 	 	Title:




 


	 	ENERGY SPECIAL SITUATIONS FUND II, L.P.,




 


	 	By: Energy Special Situations Fund Management II, LLC, its general partner




 


		By:	 







	 	 	Name:




	 	 	Title:




 


	 	ESS PARTICIPATION FUND II, L.P.,




 


	 	By: Energy Special Situations Fund Management II, LLC, its general partner




 


	 	By:	 







	 	 	Name:




	 	 	Title:




 


	 	TRF PLATFORM HOLDINGS, LLC




 





	 	By: Intervale Capital Fund III, L.P., its manager




	 	By: Intervale Capital GP III, L.P., its general partner




	 	By: Intervale Capital Associates III LLC, its general partner




 


	 	By:	 







	 	 	Name:




	 	 	Title:




 


[Signature Page to Joinder and Amendment to Subordination and Intercreditor Agreement]


 






     


     


    







 


	 	PARENT:




 


	 	FLEXENERGY POWER SOLUTIONS, LLC,




	 	a Delaware limited liability company




 


	 	By	




	 	Name:	Wes Kimmel




	 	Title:	Chief Financial Officer  




 


	 	LOAN PARTIES:




 


	 	FLEX LEASING POWER & SERVICE LLC,




	 	a Delaware limited liability company  




 


	 	By	




	 	Name:	Darin Romine




	 	Title:	Vice President–Finance







 


	 	FLEX POWER CO.,




	 	a Delaware corporation




 


		By	




	 	Name:	Darin Romine




	 	Title:	Vice President–Finance




 


[Signature Page to Joinder and Amendment to Subordination and Intercreditor Agreement]


 









     


     


    










 


	 	AGENT: 




 


	 	TEXAS CAPITAL BANK, NATIONAL ASSOCIATION, as Agent




 


		By:	 




	 	Name:	 




	 	Title:	 




 


[Signature Page to Joinder and Amendment to Subordination and Intercreditor Agreement]