JOINT FILING AGREEMENT

     The undersigned hereby agree that the statement on Schedule 13D with respect to the Common Stock of SatCon Technology Corporation is, and any amendment thereto signed by each of the undersigned shall be, filed on behalf of each undersigned pursuant to and in accordance with the provisions of 13d-1(k) under the Securities Exchange Act of 1934, as amended.

Dated: November 19, 2007

NGP Energy Technology Partners, L.P.
By: NGP ETP, L.L.C.
Its: General Partner
By:	/s/ Philip J. Deutch
Name: Philip J. Deutch
Title: Authorized Member
NGP ETP, L.L.C.
By:	/s/ Philip J. Deutch
Name: Philip J. Deutch
Title: Authorized Member
Energy Technology Partners, L.L.C.
By:	/s/ Philip J. Deutch
Name: Philip J. Deutch
Title: Sole Member and Manager
/s/ Philip J. Deutch
Philip J. Deutch