Exhibit 4.5


 


Tecogen Inc.


45 First Avenue


Waltham, MA 02451


 


Gentlemen:


 


The undersigned (the “Investor”)
hereby confirms its agreement with Tecogen Inc., a Delaware corporation (the “Company”) as follows:


 


1.     This
Subscription Agreement, including the Terms and Conditions For Purchase of Securities attached hereto as Annex I (collectively,
(this “Agreement”) is made as of the date set forth below between the Company and the Investor.


 


2.     The
Company has authorized the sale and issuance to certain investors of up to an aggregate of ● authorized and unissued shares
(the “Shares”) of its common stock, par value $0.001 per share (the “Common Stock”),
at an initial public offering price of $● per Share (the “Purchase Price”).


 


3.     The
offering and sale of the Shares (the “Offering”) are being made pursuant to (1) an effective Registration Statement
on Form S-1, File No. 333-193823 (the “Registration Statement”) filed by the Company with the Securities and
Exchange Commission (the “Commission”) (including the preliminary prospectus contained therein (the “Preliminary
Prospectus”), and (2) if applicable, certain “free writing prospectuses” (as that term is defined in Rule
405 under the Securities Act of 1933, as amended (the “Securities Act”)), that have been or will be filed
with the Commission and delivered to the Investor on or prior to the date hereof (the “Issuer Free Writing Prospectus”),
containing certain supplemental information regarding the Shares, the terms of the Offering and the Company and (3) a final prospectus
(the “Prospectus”) that has been or will be filed with the Commission and delivered to the Investor (or
made available to the Investor by the filing by the Company of an electronic version thereof with the Commission).


 


4.     The
Company and the Investor agree that at the Closing (as defined in Section 3.1 of Annex I), the Investor will purchase from
the Company and the Company will issue and sell to the Investor the Shares set forth below for the aggregate Purchase Price set
forth below. The Shares shall be purchased pursuant to the Terms and Conditions for Purchase of Securities attached hereto as Annex
I and incorporated herein by this reference as if fully set forth herein. The Investor acknowledges that the Offering
is not being underwritten by the placement agent (the “Placement Agent”) named in the Prospectus and
that there is no minimum offering amount.


 


5.     The
manner of settlement of the Shares purchased by the Investor shall be determined by such Investor as follows (check one):


 




    	 



    	 



    

 


[          ]
A.[____]          A.          Delivery by crediting the account of the Investor's prime broker (as specified
by such Investor on Exhibit A annexed hereto) with the Depository Trust Company (“DTC”) through its Deposit/Withdrawal
At Custodian (“DWAC”) system, whereby Investor's prime broker shall initiate a DWAC transaction on the Closing
Date using its DTC participant identification number, and released by VStock Transfer LLC, the Company’s transfer agent (the
“Transfer Agent”), at the Company's direction. NO LATER THAN ONE (1) BUSINESS DAY AFTER THE EXECUTION OF
THIS AGREEMENT BY THE INVESTOR AND THE COMPANY, THE INVESTOR SHALL:


 


		(I)	DIRECT THE BROKER-DEALER AT WHICH THE ACCOUNT OR ACCOUNTS TO BE CREDITED
WITH THE SHARES ARE MAINTAINED TO SET UP A DWAC INSTRUCTING THE TRANSFER AGENT TO CREDIT SUCH ACCOUNT OR ACCOUNTS WITH THE SHARES,
AND



 


		(II)	REMIT BY WIRE TRANSFER THE AMOUNT OF FUNDS EQUAL TO THE AGGREGATE
PURCHASE PRICE FOR THE SHARES BEING PURCHASED BY THE INVESTOR TO THE FOLLOWING ACCOUNT:



 


[To be separately provided to the Investor]


 


—OR—


 


[          ]
B.[____]          B.          Delivery versus payment (“DVP”) through DTC (i.e.,
on the Closing Date, the Company shall issue Shares registered in the Investor’s name and address as set forth below and
released by the Transfer Agent directly to the account(s) at Scarsdale Equities LLC (the “Placement Agent”)
identified by the Investor; upon receipt of such Shares, Agent shall promptly electronically deliver such Shares to the Investor,
and simultaneously therewith payment shall be made by the Placement Agent by wire transfer to the Company). NO LATER THAN ONE
(1) BUSINESS DAY AFTER THE EXECUTION OF THIS AGREEMENT BY THE INVESTOR AND THE COMPANY, THE INVESTOR SHALL:


 


		(I)	NOTIFY AGENT OF THE ACCOUNT OR ACCOUNTS AT THE PLACEMENT AGENT TO
BE CREDITED WITH THE SHARES BEING PURCHASED BY SUCH INVESTOR, AND



 


		(II)	CONFIRM THAT THE ACCOUNT OR ACCOUNTS AT THE PLACEMENT AGENT TO BE
CREDITED WITH THE SHARES BEING PURCHASED BY THE INVESTOR HAVE A MINIMUM BALANCE EQUAL TO THE AGGREGATE PURCHASE PRICE FOR THE SHARES
BEING PURCHASED BY THE INVESTOR.



 


IT IS THE INVESTOR’S RESPONSIBILITY
TO (A) MAKE THE NECESSARY WIRE TRANSFER OR CONFIRM THE PROPER ACCOUNT BALANCE IN A TIMELY MANNER AND (B) ARRANGE FOR SETTLEMENT
BY WAY OF DWAC OR DVP IN A TIMELY MANNER. IF THE INVESTOR DOES NOT DELIVER THE AGGREGATE PURCHASE PRICE FOR THE SHARES OR DOES
NOT MAKE PROPER ARRANGEMENTS FOR SETTLEMENT IN A TIMELY MANNER, THE SHARES MAY NOT BE DELIVERED AT CLOSING TO THE INVESTOR
OR THE INVESTOR MAY BE EXCLUDED FROM THE CLOSING ALTOGETHER.


 




    	 



    	 



    

 


6.     The
Investor represents that, except as set forth below, (a) it has had no position, office or other material relationship within the
past three years with the Company or persons known to it to be affiliates of the Company, (b) it is not a member of the Financial
Industry Regulatory Authority, Inc. (“FINRA”) or an Associated Person (as such term is defined under the FINRA’s
NASD Membership and Registration Rules Section 1011) as of the Closing, and (c) neither the Investor nor any group of Investors
(as identified in a public filing made with the Commission) of which the Investor is a part in connection with the Offering, acquired,
or obtained the right to acquire, 20% or more of the Common Stock (or securities convertible into or exercisable for Common Stock)
or the voting power of the Company on a post-transaction basis. Exceptions: 


 





 






 


(If no exceptions,
write “none.” If left blank, response will be deemed to be “none.”)


 


7.     The
Investor represents that it has received (or otherwise had made available to it by the filing by the Company of an electronic version
thereof with the Commission) the Preliminary Prospectus, dated April ●, 2014, which is a part of the Company’s Registration
Statement, the documents incorporated by reference therein and any free writing prospectus (collectively, the “Disclosure
Package”), prior to or in connection with the receipt of this Agreement. The Investor acknowledges that, prior
to the delivery of this Agreement to the Company, the Investor will receive certain additional information regarding the Offering,
including pricing information (the “Offering Information”). Such information may be provided to the Investor
by any means permitted under the Securities Act, including the Prospectus, a free writing prospectus and oral communications.


 


8.     No
offer by the Investor to buy Shares will be accepted and no part of the Purchase Price will be delivered to the Company until the
Investor has received the Offering Information and the Company has accepted such offer by countersigning a copy of this Agreement,
and any such offer may be withdrawn or revoked, without obligation or commitment of any kind, at any time prior to the Company
(or Agent on behalf of the Company) sending (orally, in writing or by electronic mail) notice of its acceptance of such offer.
An indication of interest will involve no obligation or commitment of any kind until the Investor has been delivered the Offering Information
and this Agreement is accepted and countersigned by or on behalf of the Company.


 




    	 



    	 



    

 


	Number of Shares:	 	 
	 	 	 
	Purchase Price per Share:  	$	 
	 	 	 
	Aggregate Purchase Price:  	$	 


 


Please confirm that the foregoing correctly
sets forth the agreement between us by signing in the space provided below for that purpose.


 


	 	Dated as of: April ●, 2014
	 	 
	 	 
	 	INVESTOR
	 	 
	 	By:	 
	 	Print Name:	 
	 	Title:	 
	 	Address:	 
	 	 	 


 


	Agreed and Accepted	 
	this ●th day of April, 2014:	 
	 	 
	TECOGEN INC.	 
	 	 
	By:	 	 
	 	Title:	 


 




    	 



    	 



    

 


annex
I



TERMS AND CONDITIONS FOR PURCHASE OF SECURITIES


 


1.   Authorization
and Sale of the Shares. Subject to the terms and conditions of this Agreement, the Company has authorized the sale of the Shares.


 


2.   Agreement
to Sell and Purchase the Shares; Placement Agent.


 


2.1     At
the Closing (as defined in Section 3.1), the Company will sell to the Investor, and the Investor will purchase from the
Company, upon the terms and conditions set forth herein, the number of Shares set forth on the last page of the Agreement
to which these Terms and Conditions for Purchase of Securities are attached as Annex I (the “Signature Page”)
for the aggregate purchase price therefor set forth on the Signature Page.


 


2.2     The
Company proposes to enter into substantially this same form of Subscription Agreement with certain other investors (the “Other
Investors”) and expects to complete sales of Shares to them. The Investor and the Other Investors are hereinafter
sometimes collectively referred to as the “Investors,” and this Agreement and the Subscription Agreements
executed by the Other Investors are hereinafter sometimes collectively referred to as the “Agreements.”


 


2.3     Investor
acknowledges that the Company has agreed to pay Scarsdale Equities LLC (the “Placement Agent”) a fee
(the “Placement Fee”) and to reimburse the Placement Agent for certain expenses in respect of the
sale of the Shares to the Investor.


 


2.4     The
Company has entered into a Placement Agent Agreement, dated the date hereof, (the “Placement Agreement”),
with the Placement Agent that contains certain representations, warranties, covenants and agreements of the Company that may
be relied upon by the Investor, which shall be a third party beneficiary thereof.


 


		3.	Closings and Delivery of the Securities and Funds.



 


3.1     Closing.
The completion of the purchase and sale of the Shares (the “Closing”)
shall occur at a place and time (the “Closing Date”) to be specified by the Company and the
Placement Agent, and of which the Investors will be notified in advance by the Placement Agent, in accordance with Rule 15c6-l
promulgated under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). At the Closing,
(a) the Company shall cause VStock Transfer LLC, the Company’s “Transfer Agent”, to deliver to the Investor
the number of Shares purchased by the Investor as set forth on the Signature Page registered in the name of the Investor or,
if so indicated on the Investor Questionnaire attached hereto as Exhibit A, in the name of a nominee designated by the Investor,
and (b) the aggregate purchase price for the Shares being purchased by the Investor will be delivered by or on behalf of the
Investor to the Company.


 


		3.2	Conditions to the
Obligations of the Parties.



 


(a)          Conditions
to the Company’s Obligations. The Company’s obligation to issue and sell the Shares to the Investor shall be
subject to: (i) the receipt by the Company of the purchase price for the Shares being purchased hereunder as set forth on the
Signature Page and (ii) the accuracy of the representations and warranties made by the Investor and the fulfillment of those
undertakings of the Investor to be fulfilled prior to the Closing Date.


 




    	 



    	 



    

 


(b)          Conditions
to the Investor’s Obligations. The Investor’s obligation to purchase the Shares will be subject
to the accuracy of the representations and warranties made by the Company and the fulfillment of those undertakings of the Company
to be fulfilled prior to the Closing Date, including without limitation, those contained in the Placement Agreement, and to the
condition that the Placement Agent shall not have: (a) terminated the Placement Agreement pursuant to the terms thereof or (b)
determined that the conditions to the closing in the Placement Agreement have not been satisfied. The Investor’s obligations
are expressly not conditioned on the purchase by any or all of the Other Investors of the Shares that they have agreed to purchase
from the Company. The Investor understands and agrees that, in the event that the Placement Agent in its sole discretion determines
that the conditions to closing in the Placement Agreement have not been satisfied or if the Placement Agreement may be terminated
for any other reason permitted by such Placement Agreement, then the Placement Agent may, but shall not be obligated to, terminate
such Agreement, which shall have the effect of terminating this Subscription Agreement pursuant to Section 14 below.


 


		3.3	Delivery of Funds.



 


(a)DWAC
Delivery. If the Investor elects to settle the Shares purchased by such Investor through DTC’s Deposit/Withdrawal at
Custodian (“DWAC”) delivery system, no later than one (1) business day after the execution of this Agreement
by the Investor and the Company, the Investor shall remit by wire transfer the amount of funds equal to the aggregate purchase
price for the Shares being purchased by the Investor to the following account designated by the Company:


 


[To be separately provided to the Investor]


 


(b)Delivery
Versus Payment through The Depository Trust Company. If the Investor elects to settle the Shares purchased by such Investor
by delivery versus payment through DTC, no later than one (1) business day after the execution of this Agreement by
the Investor and the Company, the Investor shall confirm that the account or accounts at the Placement Agent to be credited
with the Shares being purchased by the Investor have a minimum balance equal to the aggregate purchase price for the Shares
being purchased by the Investor.


 


		3.4	Delivery of Shares.



 


(a)DWAC Delivery.
If the Investor elects to settle the Shares purchased by such Investor through DTC’s DWAC delivery system, no later
than one (1) business day after the execution of this Agreement by the Investor and the Company, the Investor shall
direct the broker-dealer at which the account or accounts to be credited with the Shares being purchased by such Investor are maintained,
which broker/dealer shall be a DTC participant, to set up a DWAC instructing the Transfer Agent to credit such account or accounts
with the Shares. Such DWAC instruction shall indicate the settlement date for the deposit of the Shares, which date shall
be provided to the Investor by the Placement Agent. Upon the closing of the Offering, the Company shall direct the Transfer Agent
to credit the Investor’s account or accounts with the Shares pursuant to the information contained in the DWAC.


 




    	 



    	 



    

 


(b)Delivery
Versus Payment through The Depository Trust Company. If the Investor elects to settle the Shares purchased by such Investor
by delivery versus payment through DTC, no later than one (1) business day after the execution of this Agreement by
the Investor and the Company, the Investor shall notify the Placement Agent of the account or accounts at the Placement
Agent to be credited with the Shares being purchased by such Investor. On the Closing Date, the Company shall deliver the Shares
to the Investor through DTC directly to the account(s) at the Placement Agent identified by Investor. Upon receipt of such Shares,
the Placement Agent shall promptly electronically deliver such Shares to the Investor, and simultaneously therewith payment shall
be made by the Placement Agent by wire transfer to the Company.


 


		4.	Representations, Warranties and Covenants of the Investor.



 


The Investor acknowledges,
represents and warrants to, and agrees with, the Company and the Placement Agent that:


 


4.1     The
Investor (a) is knowledgeable, sophisticated and experienced in making, and is qualified to make decisions with respect to, investments
in securities presenting an investment decision like that involved in the purchase of the Shares, including investments in
securities issued by the Company and investments in comparable companies, (b) has answered all questions on the Signature Page
and the Investor Questionnaire and the answers thereto are true and correct as of the date hereof and will be true and correct
as of the Closing Date and (c) in connection with its decision to purchase the Shares set forth on the Signature Page,
has received and is relying only upon the Disclosure Package and the documents incorporated by reference therein and the Offering
Information.


 


4.2
     (a) No action has been or will be taken in any jurisdiction outside the United States by the Company or the Placement Agent
that would permit an offering of the Shares, or possession or distribution of offering materials in connection with the issue
of the Shares in any jurisdiction outside the United States where action for that purpose is required, (b) if the Investor
is outside the United States, it will comply with all applicable laws and regulations in each foreign jurisdiction in which
it purchases, offers, sells or delivers Shares or has in its possession or distributes any offering material, in all cases
at its own expense and (c) the Placement Agent is not authorized to make and has not made any representation, disclosure or use
of any information in connection with the issue, placement, purchase and sale of the Shares, except as set forth or incorporated
by reference in the Preliminary Prospectus, the Prospectus or any free writing prospectus.


 


4.3     (a)
The Investor has full right, power, authority and capacity to enter into this Agreement and to consummate the transactions contemplated
hereby and has taken all necessary action to authorize the execution, delivery and performance of this Agreement, and (b)
this Agreement constitutes a valid and binding obligation of the Investor enforceable against the Investor in accordance with
its terms, except as enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or similar laws
affecting creditors’ and contracting parties’ rights generally and except as enforceability may be subject to general
principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law) and except
as to the enforceability of any rights to indemnification or contribution that may be violative of the public policy underlying
any law, rule or regulation (including any federal or state securities law, rule or regulation).


 




    	 



    	 



    

 


4.4     The
Investor understands that nothing in this Agreement, the Preliminary Prospectus, the Disclosure Package, the Offering Information,
the Prospectus or any other materials presented to the Investor in connection with the purchase and sale of the Shares constitutes
legal, tax or investment advice. The Investor has consulted such legal, tax and investment advisors and made such investigation
as it, in its sole discretion, has deemed necessary or appropriate in connection with its purchase of Shares.


 


5.     Survival
of Representations, Warranties and Agreements; Third Party Beneficiary. Notwithstanding any investigation made by any
party to this Agreement or by the Placement Agent, all covenants, agreements, representations and warranties made by the Company
and the Investor herein will survive the execution of this Agreement, the delivery to the Investor of the Shares and the payment
therefor. The Placement Agent shall be a third party beneficiary with respect to the representations, warranties and agreements
of the Investor in Section 4 hereof.


 


6.     Notices.
All notices, requests, consents and other communications hereunder will be in writing, will be mailed (a) if within the
domestic United States by first-class registered or certified airmail, or nationally recognized overnight express courier, postage
prepaid, or by facsimile or (b) if delivered from outside the United States, by International Federal Express or facsimile, and
will be deemed given (i) if delivered by first-class registered or certified mail domestic, three business days after so mailed,
(ii) if delivered by nationally recognized overnight carrier, one business day after so mailed, (iii) if delivered by International
Federal Express, two business days after so mailed and (iv) if delivered by facsimile, upon electronic confirmation of receipt
and will be delivered and addressed as follows:


 


(a)if to the Company,
to:



Tecogen Inc.


45 First Avenue


Waltham, MA 02451


Attention: Chief Executive Officer

Fax: (781) 622-1027



with a copy (which shall not constitute notice) to:



Sullivan & Worcester LLP


One Post Office Square


Boston, MA 02109


 


Attention: Edwin L. Miller, Jr.


Fax: (617) 338-2880


 




    	 



    	 



    

 


(b)          if to the Investor,
at its address on the Signature Page hereto, or at such other address or addresses as may have been furnished to the Company in
writing.


 


7.   Changes.
This Agreement may not be modified or amended except pursuant to an instrument in writing signed by the Company and the
Investor.


 


8.   Headings.
The headings of the various sections of this Agreement have been inserted for convenience of reference only and will not
be deemed to be part of this Agreement.


 


9.   Severability.
In case any provision contained in this Agreement should be invalid, illegal or unenforceable in any respect, the validity,
legality and enforceability of the remaining provisions contained herein will not in any way be affected or impaired thereby.


 


10. Governing
Law. This Agreement will be governed by, and construed in accordance with, the internal laws of the State of New
York, without giving effect to the principles of conflicts of law that would require the application of the laws of any other
jurisdiction.


 


11.Counterparts.
This Agreement may be executed in two or more counterparts, each of which will constitute an original, but all of which, when
taken together, will constitute but one instrument, and will become effective when one or more counterparts have been signed by
each party hereto and delivered to the other parties. The Company and the Investor acknowledge and agree that the Company shall
deliver its counterpart to the Investor along with the Prospectus (or the filing by the Company of an electronic version thereof
with the Commission).


 


12.Confirmation
of Sale. The Investor acknowledges and agrees that such Investor’s receipt of the Company’s signed counterpart
to this Agreement, together with the Prospectus (or the filing by the Company of an electronic version thereof with the Commission),
shall constitute written confirmation of the Company’s sale of the Shares to such Investor.


 


13.[Reserved]


 


14.Termination.
In the event that the Placement Agreement is terminated by the Placement Agent pursuant to the terms thereof, this Agreement
shall terminate without any further action on the part of the parties hereto.


 




    	 



    	 



    

 


EXHIBIT A



TECOGEN INC.



INVESTOR QUESTIONNAIRE


 


Pursuant to Section 3 of Annex I to the Agreement,
please provide us with the following information:


 


	1.	The exact name that your Shares are to be registered in.  You may use a nominee name if appropriate:	 	 
	 	 	 	 
	2.	The relationship between the Investor and the registered holder listed in response to item 1 above:	 	 
	 	 	 	 
	3.	The mailing address of the registered holder listed in response to item 1 above:	 	 
	 	 	 	 
	4.	The Social Security Number or Tax Identification Number of the registered holder listed in the response to item 1 above:	 	 
	 	 	 	 
	5.	Name of DTC Participant (broker-dealer at which the account or accounts to be credited with the Shares are maintained):	 	 
	 	 	 	 
	6.	DTC Participant Number:	 	 
	 	 	 	 
	7.	Name of Account at DTC Participant being credited with the Shares:	 	 
	 	 	 	 
	8.	Account Number at DTC Participant being credited with the Shares: