Wind power in the United States
The U.S. Department of Energy’s 2008 report "20% Wind Energy by 2030" envisioned that wind power could supply 20% of all U.S. electric power, which included a contribution of 4% to the nation’s total electric power from offshore wind power. In order to achieve this, however, significant advances in cost, performance and reliability are needed, based on a 2011 report from a coalition of researchers from universities, industry, and government, supported by the Atkinson Center for a Sustainable Future. Obtaining 20% from wind requires about 305 GW of wind turbines, an increase of 16 GW/year after 2018, or an average increase of 14.6%/year, and transmission line improvements. Analysts estimate around 25 GW of added US wind power in 2016-18, depending on the Clean Power Plan and PTC extensions. After the current PTC phase-out in 2021, additional wind power capacity is expected to be around 5 GW per year.
In 2015, electric power generation from wind power was 10 percent or more in twelve U.S. states: Colorado, Idaho, Iowa, Kansas, Maine, Minnesota, North Dakota, Oklahoma, Oregon, and South Dakota, Vermont, and Texas.
Iowa, South Dakota, and Kansas each had more than 20 percent of their electric power generation come from wind. Twenty states now have more than five percent of their generation coming from wind.
Natural gas in the United States
In the decade 2005 to 2015, electricity generated by natural gas increased by 574 billion kilowatt-hours, more than triple the increase of the second-fastest-growing source, wind energy, which increased 173 billion kilowatt-hours over the same period. Natural gas-generated electricity increased its share of total US electricity from 18.8 percent in 2005, to 32.6 percent in 2015. The increase in gas-generated electricity was mostly at the expense of coal power, which fell from 49.6 percent of US electricity in 2005, to 33.2 percent in 2015. Natural gas surpassed coal as the number one generator of US electricity in late 2015. During the 12-month period through August 2016, natural gas generated 34.5 percent of US electricity, versus 29.8 percent for coal.