Forecasting US hydropower under climate change
S. Himmelstein | January 17, 2025
Hydroelectric power has flourished in the U.S., currently generating 27% of utility-scale renewable electricity and nearly 6% of the nation’s total utility-scale electricity. However, changing climate conditions, including earlier snowmelt and more frequent extreme events, could alter the availability of water and impact potable water supplies and hydropower production. The implications of future climatic trends for hydroelectric power capacity in the U.S. were analyzed by researchers from U.S. Pacific Northwest National Laboratory and U.S. Oak Ridge National Laboratory.
The study published in Environmental Research Letters applied 96 different hydroclimate projection frameworks to cover more than 85% of total hydropower capacity across the contiguous U.S. Hydrologic models, which estimate how watersheds respond to environmental changes, were also used to simulate hydropower operation and generation.
Nationwide, hydropower output may increase 5% by 2039 and 10% by 2059 as climate change alters weather patterns and waterways. Such increases will vary regionally and seasonally, and severe water level reductions could impact hydropower generation as the risk of regional droughts also increases.
For instance, the western U.S. could experience decreasing hydropower generation in the summer and fall as earlier snowmelt increases water availability in late winter and spring. Heavier rain in the eastern region could result in increased generation in the fall, when generation increases of 5% to 20% are also predicted for the southeastern U.S.
The researchers will continue examining climate/hydropower interactions to provide regional utilities and power system operators with consistent data to plan drought scenarios, design long-duration storage and evaluate infrastructure upgrades.