For years developers have tried to figure out how to repurpose Kaiser Steel’s former open-pit iron mine at Eagle Mountain in Riverside County. One idea: Use it as a massive landfill, a proposal that fortunately never came to fruition. The current owners of the site now want to convert it into an immense, $2.5-billion hydroelectric battery, using daytime power to pump water from a lower-elevation pit to a pit 1,400 feet farther up the mountain, then running the water downhill at night through turbines to create energy.
As California sprints to convert to all-renewable energy sources, it is confronting a persistent problem: what to do when the sun goes down and solar farms stop generating electricity, or when the doldrums hit and wind turbines stop churning. These sources produce more electricity than can be consumed immediately, but the grid doesn’t have the storage capacity to save the power for when night falls or the wind stops. And as a result, solar farms have been going offline or producers have been giving away their excess watts.
California already has several pumped-water storage systems, and that approach, while expensive to build, has been relatively reliable. It makes a certain amount of sense in places where water flows naturally, so long as the projects don’t harm the local environment. Still, technology may be making such systems obsolete, as developments in batteries and other storage technologies are preparing a path to cheaper and more efficient systems.
No, we shouldn’t pump desert groundwater near Joshua Tree to help store electricity, By The Times Editorial Board, The Los Angeles Times, May 29, 2019.