Renewable Energy in the United States
As in many other countries, renewable energy resources-based electricity dominated the renewable energy landscape in the United States, and accounted for 13.2% of the domestically produced electricity in 2012 . The states of Iowa, North Dakota, and California each generate more than 10 percent of their electricity supply from wind power, solar power, and/or geothermal power. Renewable energy reached a major milestone in the first quarter of 2011, when it contributed 11.7 percent of total US energy production (2.245 quadrillion BTUs of energy), surpassing energy production from nuclear power (2.125 quadrillion BTUs) .
Since the energy crisis in the 1970s the cost of transportation fuels has increased at a higher rate than other energy needs and combined with environmental concerns has promoted renewable transportation fuels to the center of attention in renewable energy discussions. Most cars on the road today in the United States can run on blends of up to 10% ethanol without any modifications, and motor vehicle manufacturers already produce vehicles designed to run on much higher ethanol blends. Three big American automobile manufacturers, General Motors (GM), Ford, and Chrysler are among the automobile companies that sell "flexible-fuel" cars, trucks, and minivans that can use gasoline and ethanol blends ranging from pure gasoline up to 85% ethanol (E85). There were approximately 8.35 million E85 flex-fuel vehicles in the US in 2010 .