This year, the U.S. Energy Information Administration expects hydropower generation to increase 6% and account for 250 billion kWh, based on forecasts in its Short-Term Energy Outlook (STEO). EIA said it expects hydropower to increase in nearly every part of the country, with notable increases in the southeast and northwest and Rockies.
This contrasts with last year, when U.S. hydropower generation fell to its lowest since 2001.
Northwest and Rockies
More hydropower is generated in the northwest and Rockies than any other region of the U.S. In 2023, 43% of all U.S. hydropower generation occurred in this region. However, last year’s hydropower output was the region’s lowest since at least 2010. Water supply, particularly in Washington and Oregon, was affected by a May heatwave that quickly melted the snowpack and reduced water supply for the rest of the year.
On April 4, the National Oceanic and Atmospheric Administration’s Northwest River Forecast Center (NWRFC) released its latest water supply forecast for the Pacific Northwest, which is part of the larger northwest and Rockies region. The NWRFC forecasts normal to more-than-normal water supply in the southern part of the region, around the Snake River Basin, and normal to less-than-normal water supply in the northern part by the Upper Columbia River Basin.
Because water supply and subsequent hydropower generation can vary widely from year to year, EIA uses these NWRFC forecasts as inputs to the STEO model. EIA expects 106 billion kWh of hydropower this year to be produced in the northwest and Rockies, or 3% more than in 2023.
EIA expects hydropower to account for 29% of the northwest and Rockies region’s electricity generation this year, and the increased output from hydropower resources and non-hydro renewables will reduce generation from natural gas and coal.
Southeast
The largest regional increase in hydropower this year comes from the southeast region, defined as the SERC Reliability Corporation. EIA expects hydropower generation in the southeast to increase by 4 billion kWh this year compared with last year. This region includes Alabama, Tennessee and North Carolina, which combined account for about 10% of total hydropower generating capacity in the U.S.
EIA expects hydropower to account for 5% of electricity generation in the southeast in 2024. Natural gas and nuclear are the two largest sources of electricity generation in the southeast, and EIA expects both to increase in 2024. In particular, nuclear generation will increase after the Vogtle Unit 4 generator in Georgia starts providing power to the grid during the second quarter of 2024. EIA expects these increases in natural gas, nuclear and hydropower to reduce the use of coal for electricity generation in the region.
California
California’s water supply is susceptible to drought. After a very wet year last year, annual hydropower generation increased by more than 80%, from 17 billion kWh in 2022 to 31 billion kWh in 2023. EIA expects similar hydropower generation in California this year.
The California-Nevada River Forecast Center expects California to have a near-to-above normal water supply. Water reservoirs in California are also mostly above their historical averages for this time of year. In addition, snowstorms between the end of January and end of March increased snowpack across the Sierra Nevada mountain range.
Non-hydro renewables, mainly solar and wind, are the most significant component of change in California’s electricity generation mix. EIA expects California’s non-hydro renewables to increase by 5 billion kWh in 2024.
Rest of the U.S.
EIA expects hydropower to increase in nearly every region, with notable increases in New York and the central region (Southwest Power Pool or SPP). About 6% of U.S. hydropower capacity is located in New York, and EIA expects the state’s hydropower output to increase slightly, to 29 billion kWh.
The SPP region includes many of the states just east of the Rocky Mountains. In 2023, SPP’s hydropower output fell to 11 billion kWh, the least in at least a decade. EIA expects SPP’s hydropower will increase to 14 billion kWh in 2024.
