3. Siemens

GE with a German accent. The two focus in many ways on the same markets. In 2009, Siemens' environmental portfolio generated $23 billion euros in revenue, an 11 percent increase. The conglomerate seems be a little more active than GE when it comes to acquisitions lately. Siemens spent $418 million in 2009 to acquire Solel, which builds solar thermal power plants and said in December that it wants to be a top-three supplier of wind equipment by 2012. In the past, it scooped up a number of water companies. It also has investments in startups like Energy4U and Israel's Arava Energy.

If there's a big project in the world, like the massive Desertec project that will harness North African sun for power for Europe, Siemens will invariably be involved.

‹ Previous 1 2 3 4 5 6 7 8 9 10 Next ›

Tags: batteries, california, carbon, china, cigs, cisco, doe, efficiency, electric cars, energy efficiency, feedstock, first solar, ford, general electric, green building