Forbes: The looming threat of climate change and soaring energy prices has attracted vast amounts of capital into clean energy companies in the past few years. In 2007, the sector attracted $2.2 billion in venture-backed investments, up 45% from 2006. Biofuels production jumped from 4.9 billion gallons in 2006 to roughly 6.5 billion gallons last year. Meanwhile, in 2007 the U.S. added 314 megawatts of new solar energy systems to the grid, up by 125% from the previous year. In the past …