Transcript:
As power companies add more solar and wind to the grid, they need ways to store extra energy when it’s abundant. This stored energy can then be used when needed.
Cohen: “To deal with issues like, what if the wind doesn’t blow for three days, or if it’s really cloudy for a long period of time and so on.”
Stuart Cohen of the National Renewable Energy Laboratory says batteries are one option. But another approach is pumped storage hydropower.
Pumped hydro systems require two reservoirs of water – one higher in elevation than the other.
When solar and wind energy are plentiful, that power can be used to pump water from the lower to the upper reservoir.
Cohen: “And then when you really need the electricity, you let the water fall downhill.”
The rushing water then spins a turbine, which powers a generator to produce electricity.
That part of the process is similar to how a hydroelectric power plant works. But instead of requiring a constant source of running water, pumped hydro systems use the same water over and over, so they do not need to be located on rivers.
And Cohen says pumped hydro systems can store more energy and provide power for longer than most batteries, so they could help power companies use more clean energy.
Reporting credit: Sarah Kennedy / ChavoBart Digital Media
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