The Solar Energy Industries Association (SEIA) has proposed that 700 GWh of cumulative battery energy storage could and should be built in the US – up from 83 GWh today, and a lot more ambitious than the more likely 450 GWh which will pan out in the absence of supportive policy through 2030. The SEIA’s whitepaper proposes that 10 million distributed installations can be reached, for some 140 GWh of storage capacity – so the average installation size would be roughly a 13.5 kWh Tesla Powerwall – which would leave most BESS still in the utility-scale segment. Probably the most interesting reforms, whether in two years, four years or more would be integrating batteries into the transmission network and rewarding…