Growth in power generation from renewable energy sources is being driven by climate change concerns and the resulting public agenda. With the United States importing around 60 percent of the oil it consumes, energy independence is also a potent force driving the need for homegrown sustainable energy. However, with the current uncertainty around future energy policy-including the failure of the Copenhagen Climate Summit at the end of 2009 and slim chances of a major Obama Energy Bill passing through Congress-the rapid growth of and positive sentiment for renewable energy has suffered some setbacks. Some industry observers have even started to talk about a "green energy bubble."