Exhibit 10.50

[Hercules Technology Growth Capital, Inc. Letterhead]

June 11, 2013

American Superconductor Corporation

64 Jackson Road

Devens, MA 01434

Attn: General Counsel

LIMITED WAIVER

 

  Re: Loan and Security Agreement dated as of June 5, 2012 by and between
American Superconductor Corporation (the “Borrower”) and Hercules Technology
Growth Capital, Inc. (“Lender”) (the “Agreement”)

The Lender hereby waives, (i) the requirement that the Borrower’s audited
financial statements for the fiscal year ended March 31, 2013 as set forth in
Section 6.1(b) of the Agreement be unqualified; provided however, such financial
statements shall only be limited to a going concern qualification; and (ii) any
Event of Default under Section 8.2 if the Agreement related to the waiver under
Section 6.1(b).

The foregoing is limited to the single occurrence described herein and the
Agreement shall otherwise remain unchanged in all respects.

Should you have any questions regarding this limited waiver, please do not
hesitate to call me at (650) 289-3078.

Very truly yours,

/s/ Ben Bang        

Ben Bang

Senior Counsel

Acknowledged and Agreed:

 

AMERICAN SUPERCONDUCTOR CORPORATION By:  

/s/ David A. Henry

    

Dated: June 11, 2013

 

Name: David A. Henry

Title: Senior Vice President and           Chief Financial Officer

    

400 HAMILTON AVENUE

SUITE 310

PALO ALTO, CA 94301

650.289.3060

650.473.9194

WWW.HERCULESTECH.COM