ENERGY SECURITYHydropower’s Future Is Clouded by Droughts, Floods and Climate Change – It’s Also Essential to the U.S. Electric Grid
The United States has over 2,100 operational hydroelectric dams, with locations in nearly every state. They play essential roles in their regional power grids. But most were built in the past century under a different climate than they face today. As global temperatures rise and the climate continues to change, competition for water will increase, and the way hydropower supply is managed within regions and across the power grid in the U.S. will have to evolve.
The water in Lake Powell, one of the nation’s largest reservoirs, has fallen so low amid the Western drought that federal officials are resorting to emergency measures to avoid shutting down hydroelectric power at the Glen Canyon Dam.
The Arizona dam, which provides electricity to seven states, isn’t the only U.S. hydropower plant in trouble.
The iconic Hoover Dam, also on the Colorado River, has reduced its water flow and power production. California shut down a hydropower plant at the Oroville Dam for five months because of low water levels in 2021, and officials have warned the same thing could happen in 2022.
In the Northeast, a different kind of climate change problem has affected hydropower dams – too much rainfall all at once.
The United States has over 2,100 operational hydroelectric dams, with locations in nearly every state. They play essential roles in their regional power grids. But most were built in the past century under a different climate than they face today.
As global temperatures rise and the climate continues to change, competition for water will increase, and the way hydropower supply is managed within regions and across the power grid in the U.S. will have to evolve. We study the nation’s hydropower production at a systems level as engineers. Here are three key things to understand about one of the nation’s oldest sources of renewable energy in a changing climate.
Hydropower Can Do Things Other Power Plants Can’t
Hydropower contributes 6 percent to 7 percent of all power generation in the U.S., but it is a crucial resource for managing the U.S. electric grids.
Because it can quickly be turned on and off, hydroelectric power can help control minute-to-minute supply and demand changes. It can also help power grids quickly bounce back when blackouts occur. Hydropower makes up about 40 percent of U.S. electric grid facilities that can be started without an additional power supply during a blackout, in part because the fuel needed to generate power is simply the water held in the reservoir behind the turbine.
In addition, it can also serve as a giant battery for the grid. The U.S. has over 40 pumped hydropower plants, which pump water uphill into a reservoir and later send it through turbines to generate electricity as needed.
So, while hydroelectricity represents a small portion of generation, these dams are integral to keeping the U.S. power supply flowing.
