Storing electricity to use later is critically important to the energy sector and in reducing carbon emissions.
In the US there is less than 1% capacity for energy storage, most of it in hydroelectricity, and 3% of electricity is generated from renewable sources. A team from Stanford University found hydroelectricity can store 210 times more energy than it takes to build a facility.
In contrast, the effort in making batteries, which often use rare earth materials, far outweighs their storage abilities. A rare technique called Compressed Air Energy Storage (CAES) was the most efficient form of storage.Read more at Stanford University