'Green' energy companies in Mass.

Dina Rudick/Globe Staff Photo
American Superconductor Corp.
Location: Devens
Sector: Wind
Founded: 1987
Went public: 1991
Employees: 714 as of March 31, 2010
Revenue/investment: $401 million in revenue between April 2010 and 2011
What it does: Designs and builds electrical systems for wind turbines. It also works to improve the reliability, efficiency, and capacity of power grids with renewable energy sources.