Santa Clara, Calif.
Despite a rocky start that led to the ouster of its CEO in 2007, MiaSolé is a leading maker of thin-film photovoltaic modules using copper indium gallium selenide. Within two years, it hopes to be mass-producing modules on flexible polymers that can be used as roof tiles and can generate electricity as economically as gas-fired power plants.
Key investors: Kleiner Perkins, VantagePoint, Garage Technology, Firelake