Exhibit
10.6


 


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


 


	Principal
    Amount: Up to $300,000	Dated
    as of December 31, 2020


 


Power
& Digital Infrastructure Acquisition Corp., a Delaware corporation and blank check company (the “Maker”),
promises to pay to the order of XPDI Sponsor LLC or its registered assigns or successors in interest (the “Payee”),
or order, the principal sum of up to Three Hundred Thousand Dollars ($300,000) in lawful money of the United States of America,
on the terms and conditions described below. All payments on this Note shall be made by check or wire transfer of immediately
available funds or as otherwise determined by the Maker to such account as the Payee may from time to time designate by written
notice in accordance with the provisions of this Note.


 


1. Principal.
The principal balance of this Note shall be payable by the Maker on the earlier of: (i) June 30, 2021 or (ii) the date on which
Maker consummates an initial public offering of its securities. The principal balance may be prepaid at any time. Under no circumstances
shall any individual, including but not limited to any officer, director, employee or shareholder of the Maker, be obligated personally
for any obligations or liabilities of the Maker hereunder.


 


2. Interest.
No interest shall accrue on the unpaid principal balance of this Note.


 


3. Drawdown
Requests. Maker and Payee agree that Maker may request up to Three Hundred Thousand Dollars ($300,000) for costs reasonably
related to Maker’s initial public offering of its securities. The principal of this Note may be drawn down from time to
time prior to the earlier of: (i) June 30, 2021 or (ii) the date on which Maker consummates an initial public offering of its
securities, upon written request from Maker to Payee (each, a “Drawdown Request”). Each Drawdown Request must state
the amount to be drawn down, and must not be an amount less than One Thousand Dollars ($1,000) unless agreed upon by Maker and
Payee. Payee shall fund each Drawdown Request no later than one (1) business day after receipt of a Drawdown Request; provided,
however, that the maximum amount of drawdowns collectively under this Note is Three Hundred Thousand Dollars ($300,000). No fees,
payments or other amounts shall be due to Payee in connection with, or as a result of, any Drawdown Request by Maker.


 


4. Application
of Payments. All payments shall be applied first to payment in full of any costs incurred in the collection of any sum due
under this Note, including (without limitation) reasonable attorney’s fees, then to the payment in full of any late charges
and finally to the reduction of the unpaid principal balance of this Note.


 


5. Events
of Default. The following shall constitute an event of default (“Event of Default”):


 


(a) Failure
to Make Required Payments. jFailure by Maker to pay the principal amount due pursuant to this Note within five (5) business
days of the date specified above.


 


(b) Voluntary
Bankruptcy, Etc. The commencement by Maker of a voluntary case under any applicable bankruptcy, insolvency, reorganization,
rehabilitation or other similar law, or the consent by it to the appointment of or taking possession by a receiver, liquidator,
assignee, trustee, custodian, sequestrator (or other similar official) of Maker or for any substantial part of its property, or
the making by it of any assignment for the benefit of creditors, or the failure of Maker generally to pay its debts as such debts
become due, or the taking of corporate action by Maker in furtherance of any of the foregoing.


 




     


     


    

  


(c) Involuntary
Bankruptcy, Etc. The entry of a decree or order for relief by a court having jurisdiction in the premises in respect of Maker
in an involuntary case under any applicable bankruptcy, insolvency or other similar law, or appointing a receiver, liquidator,
assignee, custodian, trustee, sequestrator (or similar official) of Maker or for any substantial part of its property, or ordering
the winding-up or liquidation of its affairs, and the continuance of any such decree or order unstayed and in effect for a period
of 60 consecutive days.


 


6. Remedies.


 


(a) Upon
the occurrence of an Event of Default specified in Section 5(a) hereof, Payee may, by written notice to Maker, declare this Note
to be due immediately and payable, whereupon the unpaid principal amount of this Note, and all other amounts payable hereunder,
shall become immediately due and payable without presentment, demand, protest or other notice of any kind, all of which are hereby
expressly waived, anything contained herein or in the documents evidencing the same to the contrary notwithstanding.


 


(b) Upon
the occurrence of an Event of Default specified in Sections 5(b) and 5(c), the unpaid principal balance of this Note, and all
other sums payable with regard to this Note, shall automatically and immediately become due and payable, in all cases without
any action on the part of Payee.


 


7. Waivers.
Maker and all endorsers and guarantors of, and sureties for, this Note waive presentment for payment, demand, notice of dishonor,
protest, and notice of protest with regard to the Note, all errors, defects and imperfections in any proceedings instituted by
Payee under the terms of this Note, and all benefits that might accrue to Maker by virtue of any present or future laws exempting
any property, real or personal, or any part of the proceeds arising from any sale of any such property, from attachment, levy
or sale under execution, or providing for any stay of execution, exemption from civil process, or extension of time for payment;
and Maker agrees that any real estate that may be levied upon pursuant to a judgment obtained by virtue hereof or any writ of
execution issued hereon, may be sold upon any such writ in whole or in part in any order desired by Payee.


 


8. Unconditional
Liability. Maker hereby waives all notices in connection with the delivery, acceptance, performance, default, or enforcement
of the payment of this Note, and agrees that its liability shall be unconditional, without regard to the liability of any other
party, and shall not be affected in any manner by any indulgence, extension of time, renewal, waiver or modification granted or
consented to by Payee, and consents to any and all extensions of time, renewals, waivers, or modifications that may be granted
by Payee with respect to the payment or other provisions of this Note, and agrees that additional makers, endorsers, guarantors,
or sureties may become parties hereto without notice to Maker or affecting Maker’s liability hereunder.


 


9. Notices.
All notices, statements or other documents which are required or contemplated by this Note shall be made in writing and delivered:
(i) personally or sent by first class registered or certified mail, overnight courier service or facsimile or electronic transmission
to the address designated in writing, (ii) by facsimile to the number most recently provided to such party or such other address
or fax number as may be designated in writing by such party or (iii) by electronic mail, to the electronic mail address most recently
provided to such party or such other electronic mail address as may be designated in writing by such party. Any notice or other
communication so transmitted shall be deemed to have been given on the day of delivery, if delivered personally, on the business
day following receipt of written confirmation, if sent by facsimile or electronic transmission, one (1) business day after delivery
to an overnight courier service or five (5) days after mailing if sent by mail.


 


10. Construction.
THIS NOTE SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH THE LAWS OF NEW YORK, WITHOUT REGARD TO CONFLICT OF LAW PROVISIONS
THEREOF.


 






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11. Severability.
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 prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any
other jurisdiction.


 


12. Trust
Waiver. Notwithstanding anything herein to the contrary, the Payee hereby waives any and all right, title, interest or claim
of any kind (“Claim”) in or to any distribution of or from the trust account (the “Trust Account”)
to be established in which the proceeds of the initial public offering (the “IPO”) to be conducted by the Maker
(including the deferred underwriters discounts and commissions) and certain of the proceeds of the sale of warrants to be issued
in a private placement to occur in connection with the closing of the IPO are to be deposited, as described in greater detail
in the registration statement and prospectus to be filed with the U.S. Securities and Exchange Commission in connection with the
IPO, and hereby agrees not to seek recourse, reimbursement, payment or satisfaction for any Claim against the Trust Account for
any reason whatsoever.


 


13. Amendment;
Waiver. Any amendment hereto or waiver of any provision hereof may be made with, and only with, the written consent of the
Maker and the Payee.


 


14. Assignment.
No assignment or transfer of this Note or any rights or obligations hereunder may be made by any party hereto (by operation of
law or otherwise) without the prior written consent of the other party hereto and any attempted assignment without the required
consent shall be void.


 


[Signature
page follows]


 




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IN WITNESS WHEREOF, Maker,
intending to be legally bound hereby, has caused this Note to be duly executed by the undersigned as of the day and year first
above written.


 


	 	POWER
    & DIGITAL INFRASTRUCTURE ACQUISITION CORP.
	 	 	 
	 	By:	/s/
    Patrick C. Eilers 
	 	 	Name:
    	Patrick
    C. Eilers
	 	 	Title:
    	Chief
    Executive Officer


 


Signature
Page to Promissory Note