Costly power grid upgrade to boost renewables will test Maine’s commitment It's becoming clear that achieving Maine's climate goals is going to require a makeover of its electric grid on a scale that hasn't happened since the 1970s. Share Maine’s ambitious goal of cutting carbon out of its economy by the mid-21st century is facing a harsh reality: The network of wires and substations built to feed power from central generating stations to homes and businesses isn’t up to the job of handling the two-way, intermittent flow of energy from solar and wind farms to electric vehicles, heat pumps and giant storage batteries.