Top Ten Solar

1. First Solar

First Solar is making an ambitious bid to conquer the project development business. The solar panel maker paid about $400 million for gigawatts worth of unfinished solar power projects from OptiSolar earlier this year, including a crown-jewel deal to build a 550-megawatt solar farm in California and sell power to the utility Pacific Gas and Electric Co. First Solar also recently won a contract to build a 48-megawatt solar power plant for Sempra Generation.

All these projects will keep the Tempe, Ariz.-based First Solar very busy in 2010. The public company has built a successful business making cadmium-telluride solar panels at its factories in the United States and Malaysia, and selling them largely to Germany and other European countries. Its ability to expand manufacturing quickly enables it to deliver the low-cost promise that many other thin-film solar panel makers have yet to fulfill. The company generated produced $348 million on $1.25 billion in revenue in 2008. It more than tripled its first-quarter net income this year and vowed to keep its panel prices ultra low to gain a strong foothold in the U.S. market.

First Solar has been a force to be reckoned with in the solar panel business, so it could do the same in the power plant engineering and construction sector. It isn't the only solar panel makers entering the project development business – SunPower and Suntech Power come to mind. First Solar has to compete with companies that specialize in developing and operating solar power plants, such as SunEdison and Fotowatio, which just bought a solar power developer, MMA Renewable Ventures.