**Exhibit 10.1**

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**LETTER AGREEMENTMODIFYING THE TERMS OF CERTAINLOAN DOCUMENTS BY AND BETWEEN GREAT WESTERN BANK,LENDER, AND TOWER TECH SYSTEMS INC., BORROWER**

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This Letter Agreement (“Agreement”)dated April 5, 2010, by and among Great Western Bank (“Lender”), TowerTech Systems Inc. (“Borrower”), and Broadwind Energy, Inc. (“Guarantor”),is intended to modify certain terms, provisions, and conditions of certain LoanDocuments (hereinafter defined), each as modified by a Letter Agreement dated April 28,2009, as further modified by a Change in Terms Agreement and Letter Agreement,each dated December 22, 2009, as further modified by a Change in TermsAgreement and Letter Agreement, each dated February 16, 2010, executed inconnection with that certain loan (the “Loan”) made by Lender to Borrower forthe purpose of financing a manufacturing facility in Brandon, South Dakota (the“Project”) on land legally described on Exhibit A attached hereto.

 

The “Loan Documents”being modified hereby are as follows:

 

·                  PromissoryNote from Borrower to Lender dated April 28, 2009 (the “Promissory Note”);

·                  CommercialGuaranty from Guarantor to Lender dated April 27, 2009 (the “CommercialGuaranty”); and

·                  Mortgage- Collateral Real Estate Mortgage - 180 Day Redemption from Borrower to Lenderdated April 28, 2009 (the “Mortgage”).

 

In addition, that certainConstruction Loan Agreement between Borrower and Lender dated April 28,2009, as modified, is being terminated and replaced in its entirety by thatcertain Business Loan Agreement between Borrower and Lender of even dateherewith (the “Loan Agreement”), as modified hereby. :

 

Modifications toPromissory Note

 

1.               At the top of thefirst page of the Promissory Note, each reference to a principal amount of$10,000,000 is changed to $6,500,000, and the reference to a maturity date of January 5,2010 is changed to November 5, 2016.

 

2.               The first paragraphof the Promissory Note entitled **PROMISE TOPAY**is amended to read as follows:

 

TOWER TECH SYSTEMS INC. (“Borrower”)promises to pay to GREAT WESTERN BANK (“Lender”), in lawful money of the UnitedStates of America, the principal amount of Six Million Five Hundred ThousandDollars ($6,500,000), or so much as may be outstanding, together with intereston the unpaid outstanding principal balance, calculated as described in the “INTERESTCALCULATION METHOD” paragraph using an interest rate of eight and one-halfpercent (8.5%) per annum based on a year of 360 days. The interest rate maychange under the terms and conditions of the “INTEREST AFTER DEFAULT” section.

 

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3.               The secondparagraph of the Promissory Note entitled **PAYMENT**is amended to read as follows:

 

Interest paymentscalculated on the principal amount of the loan remaining unpaid from time totime will be due commencing May 5, 2010, and continuing on the 5th day of each month thereafter until maturity onNovember 5, 2016 or such earlier date as the entire unpaid principalbalance of this Note shall have been paid in full. In addition to the monthlyinterest payments, principal payments in the sum of $83,333.00 will be payablemonthly commencing May 5, 2010, and continuing on the 5th day of each month thereafter until maturity onNovember 5, 2016, if not sooner paid.

 

4.               The sentence headed**Change in Ownership**under **DEFAULT**on the first page of thePromissory Note is deleted in its entirety.

 

5.               In the paragraphheaded **COLLATERAL**on the first page ofthe Promissory Note, the following is deleted: “AN ASSIGNMENT OF DEPOSITACCOUNT SAVINGS #1347401.”

 

6.               The paragraphheaded **LINE OF CREDIT**on the firstpage of the Promissory Note is deleted in its entirety.

 

Modification toCommercial Guaranty

 

1.               The definition of “Note”on page 2 of the Commercial Guaranty is hereby amended to read as follows:

 

Note. The word “note”means the promissory note from Borrower to Lender, dated April 28, 2009,in the original amount of $10,000,000, as reduced to $6,500,000 by a Change inTerms Agreement and Letter Agreement Modifying the Terms of Certain LoanDocuments by and Between Great Western Bank, Lender, and Tower Tech SystemsInc., Borrower, each dated April 5, 2010, together with all renewals of,extensions of, modifications of, refinancings of consolidations of, andsubstitutions for the promissory note or agreement.

 

Modifications to BusinessLoan Agreement

 

1.               The representationsby Borrower on pages 1 and 2 in the paragraph under the heading **Properties**are limited to Borrower’sproperties in Brandon, South Dakota.

 

2.               The first line on page 2in the paragraph under the heading **Hazardous Substances**is revised to read as follows:

 

Except as disclosed toand acknowledged by Lender in writing, and except in compliance withEnvironmental Laws, Borrower represents and warrants that: (1) During the

 

The remainder of thatparagraph remains the same.

 

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3.               On page 2, thelast line of the paragraph headed **Litigationand Claims**shall have added to it the words “in each case, of whichthe Borrower has actual knowledge.”

 

4.               On pages 3 and4, the paragraphs under the headings **Indebtednessand Liens**and **Loans, Acquisitionsand Guaranties**are deleted in their entirety.

 

5.               The sentence headed**Change in Ownership**under **DEFAULT**on page 4 is deleted in itsentirety.

 

6.               On page 5, theparagraph under the heading **Subsidiaries andAffiliates of Borrower**is deleted in its entirety.

 

7.               On page 6, thedefinition of Note is hereby amended to read as follows:

 

Note. The word “Note”means the Promissory Note executed by TOWER TECH SYSTEMS INC. dated April 28,2009, in the principal amount of $10,000,000, as reduced to $6,500,000 by aChange in Terms Agreement and Letter Agreement Modifying the Terms of CertainLoan Documents by and Between Great Western Bank, Lender, and Tower TechSystems Inc., Borrower, each dated April 5, 2010, together with allrenewals of, extensions of, modifications of, refinancings of consolidationsof, and substitutions for the note or credit agreement.

 

Modifications to Mortgage:

 

1.               The Amendment toMortgage attached hereto shall be executed and recorded in Minnehaha County,South Dakota.

 

IN WITNESSWHEREOF, Lender, Borrower and Guarantor have entered into this Letter Agreementas of the 5th day of April, 2010.

 
| LENDER:                                        | BORROWER:                                          |
|------------------------------------------------|----------------------------------------------------|
|                                           |                                               |
| GREAT WESTERN BANK                             | TOWER  TECH SYSTEMS INC.                           |
|                                           |                                               |
|                                           |                                               |
| By:                                            | /s/ Gerald E. Kruger                               |   | By: | /s/ Michael L. Salutz |
| Gerald E. Kruger,  Senior Vice President       | Michael L. Salutz,  Group Controller and Treasurer |
|                                           |                                               |   |   |
|                                           |                                               |   |   |
| GUARANTOR:                                     |                                               |   |
|                                           |                                               |   |
| BROADWIND ENERGY, INC.                         |                                               |   |
|                                           |                                               |   |
|                                           |                                               |   |
| By:                                            | /s/  Stephanie K. Kushner                          |   |   |   |
| Stephanie  K. Kushner, Chief Financial Officer |                                               |   |

 

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**EXHIBIT A**

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**LEGAL DESCRIPTION**

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Lot 3 in Block 1 ofCorson Development Park Addition to the City of Brandon, Minnehaha County,South Dakota, according to the recorded plat thereof.

 

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