Energy storage on the electricity grid has been around since the 1880s when Thomas Edison used lead-acid batteries to store power for the nighttime illumination peak. Since then hydroelectric storage, where surplus energy is used to pump water to an upper reservoir that later powers turbines to meet demand spikes, has been the main tool used by US utilities to balance their grids.
But costs, the lack of appropriate sites for such facilities, and a boom in new intermittent power generation, such as wind, solar and geothermal, require new solutions for bulk energy storage.
EPRI Journal
Michael Matz
