The largest green source is wind power, which will provide about 2 percent of the nation's electricity in 2010. However, since Congress has not required utilities to get a percentage of their power from renewable sources, demand for new wind installations has diminished. In fact, according to the American Wind Energy Association, new installations of wind generators dropped 72 percent between July and September compared with a year ago.
In addition, many people have installed solar panels, which supply the energy to heat their water, geothermal pumps that use Earth's internal warmth to heat their homes, and wood-pellet-burning stoves.
But most of those efforts will not significantly alter the way the nation heats itself, says Elias Johnson, a renewable-energy analyst at EIA. "They are growing, but it's not significant enough," he says.