Exhibit
10.21 


 


THIS NOTE
HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 OR APPLICABLE STATE SECURITIES LAWS AND MAY NOT BE TRANSFERRED, SOLD
OR OTHERWISE DISPOSED OF IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT WITH RESPECT SUCH TRANSFER, FILED AND MADE EFFECTIVE
UNDER THE SECURITIES ACT OF 1933 AND SUCH APPLICABLE STATE SECURITIES LAWS, OR UNLESS THE COMPANY RECEIVES AN OPINION OF COUNSEL
SATISFACTORY TO THE COMPANY TO THE EFFECT THAT REGISTRATION UNDER SUCH ACT AND SUCH APPLICABLE STATE SECURITIES LAWS IS NOT REQUIRED.


  


SERIES
A SECURED PROMISSORY NOTE


 






	$________________	Phoenix,
    Arizona
	 	December
    31, 2012


 


FOR
VALUE RECEIVED, PowerVerde Inc., a Delaware corporation (the “Company”) promises to pay to the order of ____________________(the
“Holder”), at such address as the Holder may designate from time to time, the principal sum of $______________, together
with simple interest at the rate of 10% per annum based on a 365-day year and actual days elapsed in the period for which such
interest is payable. Accrued interest will be paid semi-annually on June 30, 2013, December 31, 2013, June 30,
2014, and December 31, 2014. The entire principal balance of this Note, together with all unpaid interest accrued thereon,
shall be due and payable on December 31, 2014 (the “Maturity Date”). Upon payment in full of all principal and interest
payable hereunder, this Note shall be surrendered to the Company for cancellation.


 


The
Company may prepay all or any part of the amounts outstanding under this Note without premium or penalty.


 


The
Company waives presentment, demand, notice, protest, and all other demands or notices in connection with the delivery, performance,
default or enforcement of this Note. In the event of default hereunder, the Company shall, in addition to other sums due hereunder,
pay all costs and reasonable attorneys’ fees incurred in connection with any action to collect this Note at the prelitigation,
pretrial, trial and appellate levels.


 


The
principal and any interest shall be payable in lawful money of the United States of America at the address of the Holder or at
such other place as the legal holder may designate from time to time in writing to the Company.



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The
Company shall be in default and the Holder may, by notice to the Company, declare the entire unpaid principal amount of the Note
and all interest accrued and unpaid thereon due and payable, and the same shall be forthwith due and payable, if the Company fails
to make any interest payment due hereunder within 10 days after the due date thereof, fails to pay the principal and interest
due on the Maturity Date, suffers an Event of Default under the Security Agreement (as defined below), discontinues its business
or suffers a termination of the License Agreement (as defined below), or makes an assignment for the benefit of creditors, or
admits in writing its inability to pay its debts as such debts become due, or applies for or consents to the appointment of or
taking possession by a trustee, receiver or liquidator (or other similar official) of any substantial part of its property, or
commences a case or has an order for relief or liquidation entered against it or has a custodian appointed under the federal bankruptcy
laws, as now or hereafter constituted, or any other applicable federal or state bankruptcy, insolvency or other similar law, and
such case or order is not dismissed or stayed within 60 days.


 






The
Holder may waive any past default hereunder and its consequences. In the case of any such waiver, the Company and the Holder shall
be restored to their former positions and rights hereunder, respectively; but no such waiver shall extend to any subsequent or
other default or impair any right consequent thereon.


 


Upon
any such waiver, such default shall cease to exist and be deemed to have been cured and not to have occurred, and any default
arising therefrom shall be deemed to have been cured, and not to have occurred for every purpose of this Note, and the interest
rate hereon shall not be deemed to have increased; but no such waiver shall extend to any subsequent or other default impair any
right consequent thereon.


 


All
references to the “Holder” or the “Company” shall apply to their respective heirs, successors, permittees
and assigns. Notwithstanding anything herein to the contrary, this Note may not be assigned or transferred by the Company without
the prior written consent of the Holder.


 


This
Note is one of a duly authorized series of secured promissory notes in a maximum aggregate principal amount of $500,000 issued
pursuant to a form of Note Purchase Agreement dated as of December ___, 2012 (the “Purchase Agreement”), between
the Company and the Investors who are parties thereto. Terms used herein and/or otherwise not defined shall have the meaning set
forth in the Purchase Agreement.


 


This
Note is secured by a pledge of revenues under the License Agreement, as set forth in the Security Agreement of even date between
the Company, the Note holders and Paul Kelly as agent for the Note holders, and is entitled to the benefits thereof.


 


This
Note shall be governed by and construed in accordance with the laws of the State of Florida.





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IN
WITNESS WHEREOF, the undersigned has caused this Note to be signed by its duly authorized officer on the day and year first
above written.


 


	 	POWERVERDE INC.
	 	 	 
	 	By:	/s/ Richard H. Davis	 
	 	 	 
	 	Name: 	Richard H. Davis	 
	 	 	 
	 	Title:	CEO	 
	 	 	 




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