Over the past decade, U.S. wind turbines have grown in height and capacity, attributing to more efficient use of wind resources and blade length designs, according to utility-scale electricity generator data collected by the U.S. Energy Information Administration (EIA).
At higher altitudes, wind speed is increased and is not obstructed by various windbreakers, such as trees or buildings. Taller wind turbines are also able to withstand longer blades, which also contribute to increased energy generation. Since 2012, the average height of wind turbines installed has been about 280 feet, taller than they have been in previous decades.
In 2016, wind energy accounted for 8 percent of the operating electric generating capacity in the United States, making it the renewable technology with the largest installed generating capacity. In electricity generators operation, however, hydropower still provides more electricity at 7 percent of the U.S. total than wind does at 6 percent.
EIA’s Short-Term Energy Outlook does not predict that electricity generated through wind power will not surpass hydropower in 2017 or 2018.
Currently, the largest turbines installed in the United States have generating capacities of 6 megawatts (MW). They are located on the Block Island Wind Farm in Rhode Island, the only operating utility-scale offshore wind turbines in the country. Two additional offshore wind farms are planned, including one on Lake Erie near Cleveland, Ohio, in 2018, and one in Virginia in 2021.
Located in Texas, the largest onshore turbines in the United States can generate 4 MW each. The Horse Hollow Wind Energy Center, one of the world’s largest wind farms, has 420 wind turbines spread over about 47,000 acres of Texas countryside. The wind farm currently has a combined generating capacity of 735 MW.
While 40 states had utility-scale wind power projects in 2016, the most generation came from Texas, Iowa, Oklahoma, California, and Kansas, accounting for 55 percent of total U.S. wind electricity generation.