How do we heat our homes, light our rooms, and power our cars? With energy In 2014, the United States relied on fossil fuels for about 67 percent of its power. But as the fossil fuel supply dwindles and climate change becomes an increasingly urgent issue, individuals, businesses, and governments are expanding their sources of renewable energy, including solar, wind, biofuel, hydro, and geothermal. In Renewable Energy: Discover the Fuel...