Exhibit 10.1


 


Execution Version


 


THIS PROMISSORY NOTE
(“NOTE”) HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES
ACT”). THIS NOTE HAS BEEN ACQUIRED FOR INVESTMENT ONLY AND MAY NOT BE SOLD, TRANSFERRED OR ASSIGNED IN THE ABSENCE
OF REGISTRATION OF THE RESALE THEREOF UNDER THE SECURITIES ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY IN FORM, SCOPE
AND SUBSTANCE TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.


 


PROMISSORY NOTE


 


	Not to Exceed $600,000	February 3, 2021


 


FOR VALUE RECEIVED,
the undersigned TortoiseEcofn Acquisition Corp. III, a Cayman Islands exempted company (“Maker” or the
“Company”), whose business address is 5100 W. 115th Place, Leawood, KS 66211, hereby unconditionally
promises to pay to the order of TortoiseEcofin Sponsor III LLC, a Cayman Islands limited liability company (“Payee”),
at Payee’s office at 5100 W. 115th Place, Leawood, KS 66211 (or such other address specified by Payee to Maker), the sum
of SIX HUNDRED THOUSAND DOLLARS ($600,000) or such lesser amount as shall have been advanced by Payee to Maker and shall remain
unpaid under this Note, in legal and lawful money of the United States of America.


 


Payee may make advances
to Maker from time to time under this Note; provided, however, that notwithstanding anything to the contrary herein, at no time
shall the aggregate of all advances and re-advances outstanding under this Note exceed $600,000.


 


This is a non-interest
bearing Note.


 


The entire unpaid principal
balance of this Note shall be due and payable upon the earlier of (x) the date that is 180 days following the date hereof and (y)
the consummation of an initial public offering of the Company’s securities.


 


If payment of this
Note or any installment of this Note is not made when due, the entire indebtedness hereunder, at the option of Payee, shall immediately
become due and payable, and Payee shall be entitled to pursue any or all remedies to which Payee is entitled hereunder, or at law
or in equity.


 


This Note may be prepaid,
in whole or in part, without penalty. This Note may not be changed, amended or modified except in writing expressly intended for
such purpose and executed by the party against whom enforcement of the change, amendment or modification is sought. The loan evidenced
by this Note is made solely for business purposes.


 


THIS NOTE IS BEING
EXECUTED AND DELIVERED, AND IS INTENDED TO BE PERFORMED, IN THE STATE OF NEW YORK. EXCEPT TO THE EXTENT THAT THE LAWS OF THE UNITED
STATES MAY APPLY TO THE TERMS HEREOF, THE SUBSTANTIVE LAWS OF THE STATE OF NEW YORK SHALL GOVERN THE VALIDITY, CONSTRUCTION, ENFORCEMENT
AND INTERPRETATION OF THIS NOTE. IN THE EVENT OF A DISPUTE INVOLVING THIS NOTE OR ANY OTHER INSTRUMENTS EXECUTED IN CONNECTION
HEREWITH, THE UNDERSIGNED PARTIES IRREVOCABLY AGREE THAT VENUE FOR SUCH DISPUTE SHALL LIE IN ANY COURT OF COMPETENT JURISDICTION
IN THE STATE OF NEW YORK.


 


Service of any notice
by Maker to Payee or by Payee to Maker, shall be mailed, postage prepaid by certified United States mail, return receipt requested,
at the address for such party set forth in this Note, or at such subsequent address provided to the other party hereto in the manner
set forth in this paragraph for all notices. Any such notice shall be deemed given three (3) days after deposit thereof in an official
depository under the care and custody of the United States Postal Service.


 






     


     


    

 


Should the indebtedness
represented by this Note or any part thereof be collected at law or in equity or through any bankruptcy, receivership, probate
or other court proceedings or if this Note is placed in the hands of attorneys for collection after default, the undersigned and
all endorsers, guarantors and sureties of this Note jointly and severally agree to pay to the holder of this Note, in addition
to the principal and interest due and payable hereon, reasonable attorneys’ and collection fees.


 


The undersigned and
all endorsers, guarantors and sureties of this Note and all other persons liable or to become liable on this Note severally waive
presentment for payment, demand, notice of demand and of dishonor and nonpayment of this Note, notice of intention to accelerate
the maturity of this Note, notice of acceleration, protest and notice of protest, diligence in collecting, and the bringing of
suit against any other party, and agree to all renewals, extensions, modifications, partial payments, releases or substitutions
of security, in whole or in part, with or without notice, before or after maturity.


 


The undersigned hereby
expressly and unconditionally waives, in connection with any suit, action or proceeding brought by the payee on this Note, any
and every right it may have to (i) injunctive relief, (ii) a trial by jury, (iii) interpose any counterclaim therein and (iv) have
the same consolidated with any other or separate suit, action or proceeding. Nothing herein contained shall prevent or prohibit
the undersigned from instituting or maintaining a separate action against payee with respect to any asserted claim.


 


Any provision contained
in this Note which is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent
of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibitions or unenforceability
in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction.


 


This Note represents
the final agreement between the parties and may not be contradicted by evidence of prior, contemporaneous or subsequent oral agreements
of the parties.


 


[signature page follows]


 




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EXECUTED AND AGREED
as of the date first above written.


 


	 	TORTOISEECOFIN ACQUISITION CORP. III,
	 	a Cayman Islands exempted company
	 	 	 
	 	By:	/s/ Vincent T. Cubbage
	 	Name: 	Vincent T. Cubbage
	 	Title:	President, Chief Executive Officer and Chairman


 


[Signature Page to Promissory Note]