Clean technologies don't seem to make it to the top of 2010's IPO's list. According to the Wall Street Journal,

"One sector that Wall Street seems uncertain about is alternative energy or clean technology deals. Although one company had a successful IPO in that area in 2009—electric-car battery maker A123 Systems Inc.—thin-film solar-panel maker Trony Solar Holdings Co. had to postpone its deal in early December. Clean tech issuance probably isn't going to pick up until oil prices move higher, says Christopher M. Kelly, a partner at the law firm Jones Day.

"It's hard for investors to say "I'm going to invest in windmills" when they're not certain oil prices will make wind power economical," he says. "It could all change if the government pours more money into these companies, and more research and development improves the technology to the point where it becomes more economical. That will happen over time, and oil won't have to go nearly as high for alternative energy to become price-competitive."