Power stored in electric cars could be sent back to the grid – thereby supporting the grid and acting as a potential storage for clean energy – but it will only be economically viable if we upgrade the system first. In a new paper in Energy Policy, two scientists show how their seemingly contradictory findings actually point to the same outcome and recommendations: that pumping energy back into the grid using today’s technology can damage car batteries, but with improvements in the system it has the potential to provide valuable clean energy – and improve battery life in the process.