Exhibit 10.4


 


STOCK ESCROW AGREEMENT


 


This STOCK ESCROW AGREEMENT,
dated as of July 14, 2021 (“Agreement”), by and among CLEANTECH ACQUISITION CORP., a Delaware corporation (“Company”),
the initial shareholders listed on the signature pages hereto (collectively, the “Initial Shareholders”), and CONTINENTAL
STOCK TRANSFER & TRUST COMPANY, a New York corporation (“Escrow Agent”).


 


WHEREAS, the Company has entered
into an Underwriting Agreement, dated as of July 14, 2021 (“Underwriting Agreement”), with Chardan Capital Markets,
LLC (“Chardan”) acting as representative of the several underwriters (collectively, the “Underwriters”),
pursuant to which, among other matters, the Underwriters have agreed to purchase 15,000,000 units (“Units”) of the
Company, plus an additional 2,250,000 Units if the Underwriters exercise their over-allotment option in full. Each Unit consists of one
share of common stock of the Company, par value $0.0001 per share (the “Common Stock”), one right, with each right
entitling the holder thereof to purchase one-twentieth of one share of Common Stock, and one-half of a warrant, with each warrant entitling
the holder thereof to purchase one share of the Common Stock at an exercise price of $11.50 per share, all as more fully described in
the Company’s final Prospectus, dated July 14, 2021 (“Prospectus”), comprising part of the Company’s Registration
Statement on Form S-1 (File No. 333-256578) under the Securities Act of 1933, as amended (“Registration Statement”), declared
effective on July 14, 2021 (“Effective Date”).


 


WHEREAS, the Initial Shareholders
have agreed as a condition of the sale of the Units to deposit their Insider Shares (as defined in the Prospectus), as set forth opposite
their respective names on Exhibit A attached hereto (collectively “Escrow Shares”), in escrow as hereinafter
provided.


 


WHEREAS, the Company and the
Initial Shareholders desire that the Escrow Agent accept the Escrow Shares, in escrow, to be held and disbursed as hereinafter provided.


 


IT IS AGREED:


 


1. Appointment
of Escrow Agent. The Company and the Initial Shareholders hereby appoint the Escrow Agent to act in accordance with and subject to
the terms of this Agreement, and the Escrow Agent hereby accepts such appointment and agrees to act in accordance with and subject to
such terms.


 


2. Deposit
of Escrow Shares. On or prior to the date hereof, each of the Initial Shareholders delivered to the Escrow Agent certificates representing
such Initial Shareholder’s respective Escrow Shares, together with applicable share powers, to be held and disbursed subject to
the terms and conditions of this Agreement. Each of the Initial Shareholders acknowledges that the certificate representing such Initial
Shareholder’s Escrow Shares is legended to reflect the deposit of such Escrow Shares under this Agreement.


 



     


     


    





 


3. Disbursement
of the Escrow Shares.


 


3.1 The
Escrow Agent shall hold the Escrow Shares during the period (the “Escrow Period”) commencing on the date hereof and
(i) for 50% of the Escrow Shares, ending on the earlier of (x) six months after the date of the consummation of the Company’s initial
business combination (as described in the Registration Statement, hereinafter a “Business Combination”) and (y) the date on
which the closing price of the Common Stock equals or exceeds $12.50 per share (as adjusted for stock splits, stock dividends, reorganizations
and recapitalizations) for any 20 trading days within any 30-trading day period commencing after the Company’s initial Business
Combination and (ii) for the remaining 50% of the Escrow Shares, ending six months after the date of the consummation of an initial Business
Combination. The Company shall promptly provide notice of the consummation of a Business Combination to the Escrow Agent. Upon completion
of the Escrow Period, the Escrow Agent shall disburse such amount of each Initial Shareholder’s Escrow Shares (and any applicable
share power) to such Initial Shareholder; provided, however, that if the Escrow Agent is notified by the Company pursuant to Section 6.7
hereof that the Company is being liquidated at any time during the Escrow Period, then the Escrow Agent shall promptly destroy the certificates
representing the Escrow Shares; provided further, however, that if, within six months after the Company consummates an initial Business
Combination, the Company (or the surviving entity) subsequently consummates a liquidation, merger, stock exchange or other similar transaction
which results in all of the shareholders of such entity having the right to exchange their shares of Common Stock for cash, securities
or other property, then the Escrow Agent will, upon receipt of a notice executed by the Chairman of the Board, Chief Executive Officer
or other authorized officer of the Company, in form reasonably acceptable to the Escrow Agent, certifying that such transaction is then
being consummated or such conditions have been achieved, as applicable, release the Escrow Shares to the Initial Shareholders. The Escrow
Agent shall have no further duties hereunder after the disbursement or destruction of the Escrow Shares in accordance with this Section
3.1.


 


3.2 Notwithstanding
Section 3.1, if the Underwriters do not exercise their over-allotment option to purchase an additional 2,250,000 Units of the Company
in full within 45 days of the date of the Prospectus (as described in the Underwriting Agreement), the Initial Shareholders agree that
the Escrow Agent shall return to the Company for cancellation, at no cost, the number of Escrow Shares held by the Initial Shareholders
listed on Exhibit B determined by multiplying (a) the product of (i) 562,500 multiplied by (ii) a fraction, (x) the numerator of
which is the number of Escrow Shares held by each such holder, and (y) the denominator of which is the total number of Escrow Shares,
by (b) a fraction, (i) the numerator of which is 2,250,000 minus the number of shares of Common Stock purchased by the Underwriters upon
the exercise of their over-allotment option, and (ii) the denominator of which is 2,250,000. The Company shall promptly provide notice
to the Escrow Agent of the expiration or termination of the Underwriters’ over-allotment option and the number of Units, if any,
purchased by the Underwriters in connection with their exercise thereof.


 


4. Rights
of Initial Shareholders in Escrow Shares.


 


4.1 Voting
Rights as a Shareholder. Subject to the terms of the Insider Letters described in Section 4.4 hereof and except as herein provided,
the Initial Shareholders shall retain all of their rights as shareholders of the Company during the Escrow Period, including, without
limitation, the right to vote such shares.


 






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4.2 Dividends
and Other Distributions in Respect of the Escrow Shares. During the Escrow Period, all dividends payable in cash with respect to the
Escrow Shares shall be paid to the Initial Shareholders, but all dividends payable in stock or other non-cash property (“Non-Cash
Dividends”) shall be delivered to the Escrow Agent to hold in accordance with the terms hereof. As used herein, the term “Escrow
Shares” shall be deemed to include the Non-Cash Dividends distributed thereon, if any.


 


4.3 Restrictions
on Transfer. During the Escrow Period, the only permitted transfers of the Escrow Shares will be (a) to officers or directors of the
Company, any affiliates or family members of any of officers or directors of the Company, any members of CleanTech Sponsor I LLC or CleanTech
Investments, LLC, or any affiliates of CleanTech Sponsor I LLC or CleanTech Investments, LLC; (b) in the case of an individual, by gift
to a member of the individual’s immediate family or to a trust, the beneficiary of which is a member of the individual’s immediate
family, an affiliate of such person or to a charitable organization; (c) in the case of an individual, by virtue of laws of descent and
distribution upon death of the individual; (d) in the case of an individual, pursuant to a qualified domestic relations order; (e) by
private sales or transfers made in connection with the consummation of an initial Business Combination at prices no greater than the price
at which the shares or warrants were originally purchased; (f) in the event of liquidation of the Company prior to the completion of its
initial Business Combination; (g) by virtue of the laws of Delaware or the applicable limited liability company agreement upon dissolution
of CleanTech Sponsor I LLC or CleanTech Investments, LLC, or (h) for the cancellation of up to 562,500 shares of Common Stock subject
to forfeiture to the extent that the Underwriters’ over-allotment is not exercised in full or in part or in connection with the
consummation of our initial Business Combination, provided, however, that in the case of clauses (a) through (e) or (g), these permitted
transferees must enter into a written agreement agreeing to be bound by these transfer restrictions and the other restrictions contained
in the Insider Letter (as defined below) with respect to such securities (including provisions thereof relating to voting, the trust account
and liquidation distributions).


 


4.4 Insider
Letters. Each of the Initial Shareholders has executed a letter agreement with Chardan and the Company, the form of which is filed
as an exhibit to the Registration Statement (“Insider Letter”), respecting the rights and obligations of such Initial
Shareholder in certain events, including but not limited to the liquidation of the Company.


 


5. Concerning
the Escrow Agent.


 


5.1 Good
Faith Reliance. The Escrow Agent shall not be liable for any action taken or omitted by it in good faith and in the exercise of its
own best judgment, and may rely conclusively and shall be protected in acting upon any order, notice, demand, certificate, opinion or
advice of counsel (including counsel chosen by the Escrow Agent), statement, instrument, report or other paper or document (not only as
to its due execution and the validity and effectiveness of its provisions, but also as to the truth and acceptability of any information
therein contained) which is believed by the Escrow Agent to be genuine and to be signed or presented by the proper person or persons.
The Escrow Agent shall not be bound by any notice or demand, or any waiver, modification, termination or rescission of this Agreement
unless evidenced by a writing delivered to the Escrow Agent signed by the proper party or parties and, if the duties or rights of the
Escrow Agent are affected, unless it shall have given its prior written consent thereto.


 






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5.2 Indemnification.
The Escrow Agent shall be indemnified and held harmless by the Company from and against any expenses, including counsel fees and disbursements,
or loss suffered by the Escrow Agent in connection with any action, suit or other proceeding involving any claim which in any way, directly
or indirectly, arises out of or relates to this Agreement, the services of the Escrow Agent hereunder, or the Escrow Shares held by it
hereunder, other than expenses or losses arising from the gross negligence or willful misconduct of the Escrow Agent. Promptly after the
receipt by the Escrow Agent of notice of any demand or claim or the commencement of any action, suit or proceeding, the Escrow Agent shall
notify the other parties hereto in writing. In the event of the receipt of such notice, the Escrow Agent, in its sole discretion, may
commence an action in the nature of interpleader in an appropriate court to determine ownership or disposition of the Escrow Shares or
it may deposit the Escrow Shares with the clerk of any appropriate court or it may retain the Escrow Shares pending receipt of a final,
non-appealable order of a court having jurisdiction over all of the parties hereto directing to whom and under what circumstances the
Escrow Shares are to be disbursed and delivered. The provisions of this Section 5.2 shall survive in the event the Escrow Agent resigns
or is discharged pursuant to Sections 5.5 or 5.6 below.


 


5.3 Compensation.
The Escrow Agent shall be entitled to reasonable compensation from the Company for all services rendered by it hereunder. The Escrow Agent
shall also be entitled to reimbursement from the Company for all expenses paid or incurred by it in the administration of its duties hereunder
including, but not limited to, all counsel, advisors’ and agents’ fees and disbursements and all taxes or other governmental
charges.


 


5.4 Further
Assurances. From time to time on and after the date hereof, the Company and the Initial Shareholders shall deliver or cause to be
delivered to the Escrow Agent such further documents and instruments and shall do or cause to be done such further acts as the Escrow
Agent shall reasonably request to carry out more effectively the provisions and purposes of this Agreement, to evidence compliance herewith
or to assure itself that it is protected in acting hereunder.


 


5.5 Resignation.
The Escrow Agent may resign at any time and be discharged from its duties as escrow agent hereunder by its giving the other parties hereto
written notice and such resignation shall become effective as hereinafter provided. Such resignation shall become effective at such time
that the Escrow Agent shall turn over to a successor escrow agent appointed by the Company, the Escrow Shares held hereunder. If no new
escrow agent is so appointed within the 60 day period following the giving of such notice of resignation, the Escrow Agent may deposit
the Escrow Shares with any court it reasonably deems appropriate.


 


5.6 Discharge
of Escrow Agent. The Escrow Agent shall resign and be discharged from its duties as escrow agent hereunder if so requested in writing
at any time by the other parties hereto, jointly, provided, however, that such resignation shall become effective only upon acceptance
of appointment by a successor escrow agent as provided in Section 5.5.


 






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5.7 Liability.
Notwithstanding anything herein to the contrary, the Escrow Agent shall not be relieved from liability hereunder for its own gross negligence
or its own willful misconduct.


 


5.8 Waiver.
The Escrow Agent hereby waives any right of set-off or any other right, title, interest or claim of any kind (“Claim”)
in, or to any distribution of, the Trust Account (as defined in that certain Investment Management Trust Agreement, dated as of the date
hereof, by and between the Company and the Escrow Agent as trustee thereunder) and hereby agrees not to seek recourse, reimbursement,
payment or satisfaction for any Claim against the Trust Account for any reason whatsoever.


 


6. Miscellaneous.


 


6.1 Governing
Law. This Agreement shall for all purposes be deemed to be made under and shall be construed in accordance with the laws of the State
of New York, without giving effect to conflicts of law principles that would result in the application of the substantive laws of another
jurisdiction.


 


6.2 Third
Party Beneficiaries. Each of the Initial Shareholders hereby acknowledges that Chardan is a third party beneficiary of this Agreement
and this Agreement may not be modified or changed without the prior written consent of Chardan.


 


6.3 Entire
Agreement. This Agreement contains the entire agreement of the parties hereto with respect to the subject matter hereof and, except
as expressly provided herein, may not be changed or modified except by an instrument in writing signed by the party to the charged.


 


6.4 Headings.
The headings contained in this Agreement are for reference purposes only and shall not affect in any way the meaning or interpretation
thereof.


 


6.5 Binding
Effect. This Agreement shall be binding upon and inure to the benefit of the respective parties hereto and their legal representatives,
successors and assigns.


 






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6.6 Notices.
Any notice or other communication required or which may be given hereunder shall be in writing and either be delivered personally or be
mailed, certified or registered mail, or by private national courier service, return receipt requested, postage prepaid, and shall be
deemed given when so delivered personally or, if mailed, two days after the date of mailing, as follows:


 


If to the Company, to:


 


CleanTech Acquisition Corp.

207 West 25th Street, 9th Floor

New York, NY 10001

Attn: Eli Spiro


 


If to a Shareholder, to his address set forth in Exhibit
A.


 


and if to the Escrow Agent,
to:


 


Continental Stock Transfer& Trust Company

1 State Street, 30th Floor

New York, New York 10004

Attn: Isaac Kagan


 


A copy (which copy shall not
constitute notice) sent hereunder shall be sent to:


 


Chardan Capital Markets LLC

17 State Street, 21st Floor

New York, NY 10004

Attn: Jonas Grossman

Fax: (646) 465-9002


 


and:


Cooley LLP

55 Hudson Yards

New York, New York 10001

Attn: Yvan-Claude Pierre; Peter Byrne

Email: ypierre@cooley.com

           pbyrne@cooley.com


 


Fax:


 


and:


Loeb & Loeb LLP

345 Park Avenue

New York, New York 10154

Attn: Mitchell S. Nussbaum and Giovanni Caruso

Fax: (212) 407-4000


 


The parties may change the
persons and addresses to which the notices or other communications are to be sent by giving written notice to any such change in the manner
provided herein for giving notice.


 


6.7 Liquidation
of the Company. The Company shall give the Escrow Agent written notification of the liquidation and dissolution of the Company in
the event that the Company fails to consummate a Business Combination within the time period specified in the Prospectus.


 


[Signature Page Follows]




 






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WITNESS the execution of this
Agreement as of the date first above written.


 


	 	COMPANY:
	 	 
	 	CLEANTECH ACQUISITION CORP.
	 	 
	 	By:	/s/ Eli Spiro
	 	 	Name: Eli Spiro
	 	 	Title:   Chief Executive Officer
	 	 	 
	 	CONTINENTAL STOCK TRANSFER & TRUST COMPANY
	 	 
	 	By:	/s/ Erika Young
	 	 	Name: Erika Young
	 	 	Title:   Vice President
	 	 	 
	 	INITIAL SHAREHOLDERS:
	 	 
	 	CLEANTECH SPONSOR I LLC
	 	 
	 	By:	/s/ Eli Spiro
	 	 	Name: Eli Spiro
	 	 	Title:   Manager
	 	 	 
	 	CLEANTECH INVESTMENTS, LLC
	 	 
	 	By:	/s/ Jonas Grossman
	 	 	Name: Jonas Grossman
	 	 	Title:   Managing Member
	 	 	 
	 	 	Bill Richardson
	 	 	 
	 	 	/s/ Bill Richardson
	 	 	 
	 	 	Jon Najarian
	 	 	 
	 	 	/s/ Jon Najarian
	 	 	 
	 	 	Brendan Riley
	 	 	 
	 	 	/s/ Brendan Riley
	 	 	 
	 	 	Douglas Cole
	 	 	 
	 	 	/s/ Douglas Cole



 


	 	 	 
	 	 	Britt Ide
	 	 	 
	 	 	/s/ Britt Ide
	 	 	 
	 	 	Allen Weiss
	 	 	 
	 	 	/s/ Allen Weiss
	 	 	 
	 	 	Dan Reicher
	 	 	 
	 	 	/s/ Dan Reicher



 






     


     


    




 


EXHIBIT A


 


Initial Shareholders


 


	Name of Initial Shareholder	 	Number  of Shares	 
	CleanTech Sponsor I LLC	 	[_]	 
	CleanTech Investments, LLC	 	[_]	 
	[_]	 	[_]	 
	[_]	 	[_]	 
	[_]	 	[_]	 





 












    A-1


     


    




 


EXHIBIT B


 


Escrow Shares


 


CleanTech Sponsor I LLC – [_]


 


CleanTech Investments, LLC – [_]


 


 


B-1