It's been a busy time for cleantech IPOs. Several companies, including GT Solar, Noble Environmental Power and Real Goods Solar, have thrown their hats in the ring in recent weeks -- though often with little success. The latest is First Wind, a Newton, Mass.-based wind power developer, which has just filed for a $450 million IPO.

Its co-lead underwriters are Credit Suisse, Goldman Sachs and JPMorgan; it will trade on the NASDAQ under the ticker symbol "WINDY". It said it will sell Class A shares though it hasn't disclosed the exact number or share price. The proceeds will be used to repay debt and to fund part of its 2008-9 capital expenditures.

Founded in 1995, First Wind develops, manages and owns 3 wind farms, located in the Northeast, West and Hawaii, that produce 92 megawatts. It has a further 182 megawatts of capacity under construction and a pipeline of 5,564 megawatts.

The company hopes to have around 1,100 megawatts of operating capacity by the end of 2010 and 2,300 megawatts by the end of 2013. It reported $12.3 million in revenue for 2007, including a net loss of $68 million; it currently employs 130 people.