On September 10, 2018, California Governor Jerry Brown signed into law a bill mandating that California’s electric power sector source 100% of its power from carbon-free energy sources by 2045. The bill accelerates California’s existing renewable mandate, requiring that 50% of the state’s electricity come from renewable sources by 2025, and 60% by 2030. Already, by end-2017, 32% of California’s electricity was sourced from renewables.
While California is the second state after Hawaii to establish a 100% carbon-free electricity goal, the move has more significance given the sheer size of California’s electricity market and economy. California, on its own, has an economy larger than that of the UK. If it is able to proceed smoothly toward its goal of 100% carbon-free electricity, it will send a strong signal to other countries—not to mention US states—that such a move is possible.
California’s rapid adoption of renewable energy has already moved the needle in neighboring states such as Nevada. Nevada’s main electric utility, NV Energy, buys excess renewable power from California during the middle of the day for less than it would cost to generate it itself. Perhaps for this reason, NV Energy sat on the sidelines while environmental advocates pushed a successful ballot measure this fall in the state, which will require the state to get 50% of its electricity from renewables by 2030.
But California will face certain hurdles in creating a 100% carbon-free electricity sector. Because wind and solar energy are not constant, California will rely in part on nuclear energy and hydropower, and in part on energy storage, to provide electricity when solar and wind are not available. Energy storage costs must continue to fall, and utility-scale energy storage projects become commonplace to make this happen.