Renewable energy provides the best hope to move electrical power grids away from fossil fuels and the emission of climate-altering greenhouse gases (GHGs). Wind and solar are two of the leading sustainable energy sources, however each is intermittent by nature and must be augmented by electrical energy storage if they are to play central roles in the foundation of a reliable electrical power grid.
Energy storage is not new—The first use of pumped-storage in the United States was in 1930 by the Connecticut Electric and Power Company near New Milford, Connecticut, storing excess energy by pumping water from the Housatonic River into a storage reservoir located 230 feet above the river. Today, about 96 percent of global energy storage comes from the same kind of pumped hydro energy storage (PHES).
There are a variety of other technologies available to store energy and several of them are particularly useful when it comes to storing renewable energy. Electrochemical storage batteries (in particular lithium-ion batteries), redox flow batteries, hydrogen storge, thermal systems, pumped fluids, and even an idle fleet of electric vehicles (EVs) all have their proponents.
Let’s have a look at 9 different energy storage technologies that are now or will soon be in commercial use. Combinations of these systems that allow renewables to take over a substantial part of the electric power grid in the coming years, so now is the time to get to know them.
Kevin Clemens is a Senior Editor with Battery Technology.