Im hoping this is a fairly significant year for batt storage with the Tesla batt factory nearing completion, Daimler getting into the market, Panasonic getting new competition on their heels. Reading about energy storage and ignoring portability it seems to me that electrochemical may not be the best solution. The mechanical simplicity of gravitational potential energy and solar power makes me drool. lol Apparently even flywheels are used to "store" energy. kept in vacuums supported with magnetic bearings, made of carbon fiber and rotating at up 60k rpm! Oh that's a cool one too! So cool when star trek complexity and flinstone simplicity converge.