The United States witnessed a significant downturn in hydropower electricity generation last year, marking its lowest output since 2001. However, a forecast in the Short-Term Energy Outlook (STEO) indicates a promising 6% increase in hydropower generation for the current year. It is projected to contribute approximately 250 billion kilowatthours to the electricity generation sector nationwide. Notably, this surge is expected to be widespread, with significant gains anticipated in regions such as the Southeast, Northwest, and Rockies.
Northwest and Rockies
The Northwest and Rockies region, which historically boasts the highest hydropower generation in the country, faced a setback in 2023 with its lowest output since at least 2010. This decline was largely attributed to adverse weather conditions, particularly a May heatwave that rapidly depleted snowpack and subsequently impacted water supply in states like Washington and Oregon.
Recent forecasts from the National Oceanic and Atmospheric Administration’s Northwest River Forecast Center (NWRFC) provide cautious optimism. The center predicts a mix of normal to more-than-normal water supply in the southern part of the region, while the northern areas, encompassing the Upper Columbia River Basin, are anticipated to experience normal to less-than-normal water supply. These forecasts serve as crucial inputs for the STEO model, with an expected increase of 3% in hydropower generation for the region, totaling 106 billion kilowatthours in 2024.
Southeast
The Southeast region, represented by the SERC Reliability Corporation, anticipates the most substantial surge in hydropower generation this year. This includes states like Alabama, Tennessee, and North Carolina, which collectively account for about 10% of the nation’s total hydropower capacity. With an estimated increase of 4 billion kilowatthours compared to the previous year, hydropower is projected to contribute 5% to the region’s electricity generation in 2024.
California
In California, a state prone to drought, the outlook is cautiously optimistic following a wetter-than-average year in 2023. This resulted in a remarkable 80% increase in hydropower generation. Similar conditions are expected this year, with the California-Nevada River Forecast Center forecasting a near-to-above normal water supply. Additionally, the state’s water reservoirs are currently above historical averages, and improved snowpack levels across the Sierra Nevada mountain range further bolster confidence.
Despite the prominence of hydropower, California’s electricity generation mix is increasingly being shaped by nonhydro renewables, primarily solar and wind. It is projected that these sources will contribute an additional 5 billion kilowatthours to the state’s energy mix in 2024.
Rest of the United States
Expectations for increased hydropower generation extend beyond the aforementioned regions, with notable upticks anticipated in New York and the Central region, particularly the Southwest Power Pool (SPP). New York, home to approximately 6% of the nation’s hydropower capacity, is poised to witness a slight increase in output to 29 billion kilowatthours. Meanwhile, the SPP region, which experienced a decade-low output in 2023, is projected to rebound to 14 billion kilowatthours in 2024.