Hydroelectricity represented the largest share of electricity generation among renewable sources in 19 states in 2017, according to the U.S. Energy Information Administration.
By comparison, hydro was the largest renewable electricity source in 28 states in 2007. EIA says the drop in 2017 correlates with wind and solar becoming more common. Wind was the most prevalent renewable electricity generation source in 16 states in 2017 and solar was the most prevalent in seven states.
In addition, hydropower was the most prevalent of all electricity generation sources in six states in 2017. Washington had the largest hydroelectricity share in 2017, at 72% of the state’s total electricity generation. The other states were Oregon, Idaho, Vermont, South Dakota and Maine. Among all of the electricity generation sources, hydroelectricity is the only renewable source to be the most common among all sources in any state, EIA says.
However, wind was the second largest electricity generation source in six states. EIA says that as more wind turbines are constructed and come online, Kansas and Iowa may become the first states to have a renewable source other than hydroelectricity provide the largest share of their electricity generation.
Electricity generated from biomass had the second largest generation share in three states in 2017, and the share of electricity generate by biomass trails only hydro in Maine and Vermont, making them two of only three states where renewable fuels provided both of the top two generation shares. The third is South Dakota, where hydroelectricity and wind were the most prevalent sources.
Solar was the second largest generation source in only one state, Nevada. Solare generation’s share is highest in California, where it provided 16% of the state’s 2017 total.
For the U.S. as a whole, hydro was the highest renewable electricity generation source in 2017, providing 7% of the national total. However, EIA says that by 2019 wind is expected to surpass hydro, based on the latest forecasts in its Short-Term Energy Outlook.