According to a new report from the U.S. Energy Information Administration (EIA), the U.S. will generate 14 percent more electricity from solar energy than from hydroelectric facilities in 2024. The EIA’s forecast is driven by continued growth in new utility-scale and small-scale solar facilities.

In 2019, annual wind generation surpassed annual hydropower generation.

In September 2022, for the first time, the U.S. had more solar-generated electricity than hydroelectric generation on a monthly basis, according to the EIA’s “Electric Power Monthly.” That month, U.S. solar power plants and rooftop solar generated about 19 billion kilowatthours, (kWh) compared with 17 billion kWh from U.S. hydropower plants. “Solar power outpaced hydropower again this summer due to exponential growth in installed solar capacity,” said the EIA.

From 2009 to 2022, installed solar capacity increased at an average rate of 44 percent per year, and installed hydroelectric capacity increased by less than one percent each year.

In its “Short Term Energy Outlook” report, the EIA said it expects annual solar generation to surpass annual hydropower generation in 2024 for the first time ever.

“The growth of U.S. solar and U.S. wind generation are following a similar pattern, both largely following growth in installed capacity,” said the EIA. Incentives such as investment tax credits have encouraged growth in renewable generation capacity. By August 2023, installed U.S. solar capacity totaled more than 125 gigawatts (GW), including 80 GW of utility-scale solar capacity and an estimated 45 GW of small-scale solar capacity. Hydroelectric capacity in the U.S. has remained relatively steady at about 80 GW for the past few decades.

Also contributing to the trend, weather patterns reduced U.S. hydropower generation through August of 2023. “Hydropower generation depends on seasonal hydrologic conditions and long-term weather trends,” said the EIA. “Although weather patterns also affect solar and wind generation, the biggest contributor to additional generation from these sources is they have had the fastest growth in generating capacity.”

During times of high demand or high prices, hydroelectric generators have reservoirs that can store water to be released through dams to generate electricity. This ability to control the output is limited by long-term hydrologic conditions and other complications associated with water rights and recreational uses. “Despite these challenges, hydropower continues to be a key source in the hourly pattern of generation in areas like the Pacific Northwest,” added the EIA.