On hot days in California, people turn on their air conditioners, and demand for electricity spikes. Winter is a distant memory, but the snow that fell then helps the state meet its energy needs now.

That’s because in California, much of the water used to produce hydropower comes from melting mountain snowpack.

Yarnell: “Snowpack provides a great storage reservoir up at a high elevation to hold back potential water that could then feed into a power house or into a turbine. We also have small lakes and reservoirs all along the High Sierra.”

That’s Sarah Yarnell of the University of California-Davis. She says hydropower is an important resource …

Yarnell: “… because we can turn it off and on exactly when we need it, assuming that the water is stored up high either in the snowpack or in a reservoir up high.”

But that resource is dwindling.

Yarnell: “We’re below average on our snow pack this year – not as dire as it was in 2014 and 2015 when we virtually had no snow in the high elevations, but we do have a low snow pack this year.”

As the climate warms and snowpack declines, hydropower plants will have a harder time meeting the state’s electricity needs.

Yarnell: “These are things that we’ll need to take into account as we assess our energy needs into the future.”

Reporting credit: Christine Hoover Moorehead/ChavoBart Digital Media.
Image credit: NASA/MODIS.