Fuelcell Energy Inc
A maker of large molten carbonate fuel cell power plants that turn natural gas, biogas, or hydrogen into continuous electricity for utilities, industrial sites, and municipalities. It began in 1969 as Energy Research Corporation, a small Connecticut lab founded by chemical engineers, and took its present name in 1999 after spinning off its battery business. Its flagship "Direct FuelCell" technology converts fuel to power right inside the stack—hence the name.