Pumped Hydro Could Deliver 100 Percent Renewable Electricity
Achieving 100 percent renewable power will require a lot of energy storage. And while the cost and availability of storage batteries have made significant progress lately, they may not be the best solution to store renewable energy.
A new study by researchers at the Australian National University has identified 530,000 sites around the world suitable for pumped hydro storage that can store up to 22 million gigawatt hours of electricity.
Pumped hydro storage is old technology. It uses excess electricity produced at night to pump water uphill into reservoirs or storage tanks, then works like conventional hydro-electricity to spin turbines as the water flows back downhill during the day. Unlike conventional hydro, it doesn’t generate net new power but does improve grid reliability and enable new sources of renewable electricity to come online, according to the U.S. Energy Information Agency.
The storage would be needed to take full advantage of renewable wind and solar power even when consumers are not demanding peak power, and then supply that power back to the grid at times when they do.