by Emil Morhardt
How about storing the excess energy not chemically in batteries, inot as potential energy in pumped hydroelectric reservoirs, not as compressed air, or heat, but just as excess charges? That’s what capactors do, and supercapacitors are widely used for storing not-too-much energy for immediate release when needed. What if the electrical cables themselves could be turned into supercapacitors. Yu and Thomas (2014) figured out how to do just that by using nanowires spaced around the central charge carrying cable to accumulate the excess charge. If wires like this become economic, they could be used to connect photovoltaic panels and wind turbines to the grid, automatically levelling out the delivery of power when the source becomes intermittent.
Yury Gogotsi writes about it in the 29 May 2014 issue of Nature