'Green' energy companies in Mass.
Energy efficiency/demand response
Went public: 2007
Employees: 600+ (350 in Massachusetts, and 250 scattered across North America, Australia, and the UK)
Revenue/investment: $280.2 million in revenue in 2010
What it does: This energy technology company pays its 2,500 commercial, institutional, and industrial clients to reduce electricity consumption during times of peak demand.