ENERGY SECURITYHydropower Generation Projected to Rise, but Climate Change Brings Uncertain Future
A new analysis combines hydrology data with climate change models to help water managers prepare for hydropower’s future.
In a new study assessing how climate change might alter hydropower generation across the continental United States, researchers show that except for some parts of the Southwest, hydropower generation is expected to rise in the future.
The analysis also shows that in the Pacific Northwest in the future, less water will be stored in the mountains as snowpack in the winter as warmer temperatures bring more rain. This seasonal shift will challenge water managers and grid operators to rebalance how and when to use dams to produce electricity.
“We know the climate is changing and we know that’ll affect how much water will be available to produce hydropower,” said Daniel Broman, a hydro-climatologist at the Department of Energy’s Pacific Northwest National Laboratory and lead author on the new paper. “Our research provides a consistent look across the country, so even if water and energy planners are only looking ahead regionally, our data can provide a broader outlook.”
The new study published on August 8 in Environmental Research Letters.
How Climate Change Affects Hydropower
Water flows through 2,250 hydropower facilities across the United States, contributing 6% of the country’s electricity. Hydropower dominates in the Pacific Northwest, providing 60% of energy in the region. Dam operations don’t just consider power, they also consider flood control, transportation routes and water for irrigation and support fisheries and natural ecosystems. So, understanding how water availability will change in the future is important for water managers when planning for their various resource needs.
To support this planning, DOE periodically releases a report known as the 9505 Assessment (referring to Section 9505 of the SECURE Water Act). The report provides a detailed assessment of climate change’s effects on hydropower facilities. The third of these reports was delivered to Congress in December of 2023.
But that report only includes 132 facilities, all federally owned. The power they generate makes up 46% of the nation’s hydropower capacity, said study coauthor Nathalie Voisin, chief scientist for water-energy dynamics at PNNL and a lead researcher on the project. To better understand how climate change may affect hydropower generation across the entire continental United States, the researchers added streamflow and hydropower generation data from an additional 1,412 non-federal facilities.
