MIT Technology Review
: Conventional batteries are too expensive and inefficient to store extra energy produced by solar plants and wind farms. Currently fossil fuels provide the power needed when it is dark or not windy. An alternative to conventional batteries are flow batteries
, which have lower energy densities and are just as expensive, but are cleaner and last longer. A new variation on flow batteries developed by Yet-Ming Chiang of MIT incorporates nanoparticles in the liquid used by the battery to store the energy. Those nanoparticles create a network that can carry the electricity through the liquid even while it is flowing. In testing, the energy density of the modified battery was five to six times that of the unmodified battery. Chiang thinks that scaling up the process could lower the battery cost below the $100/kWh that the Department of Energy estimates would make batteries economical for inclusion in the electrical grid.