DE-carbonizing The world's electricity supply will require more than solar panels and wind turbines, which rely on sunlight and steady winds to produce electricity. Grid-scale storage offers a solution to this intermittency problem, but little is known about it. International Energy Agency (IEA), an authoritative forecaster, believes that global installed capacity Battery Storage would need to be scaled up to less than 200 GW (Guinea worm) more than a terawatt last year (T.W.) by the end of the decade, and about 5T.W. by 2050, if the world is to remain on a path to net-zero emissions (see chart 1). Fortunately, though, the business of energy storage on the grid is finally picking up.