California close to setting ambitious clean energy goal

California is on the cusp of adopting one of the most aggressive clean energy goals in the US.

The state Assembly yesterday voted 43-32 in favor of SB 100, a bill to require all of California's electricity to come from zero-carbon sources by 2045.

The bill now goes back to the Senate for a vote on minor changes made in the Assembly. Supporters see the step as a formality as a majority of senators voted to approve largely the same measure last year.

The legislation would then go to governor Jerry Brown (D), who has not said whether he will sign it. Brown has supported past efforts to increase the state's renewable energy use.

"Today, California took another great stride toward a 100pc clean energy future. SB100 will spur technological innovation, jump-start new jobs and keep our air clean," said state senator Kevin de Leon (D), the bill's lead sponsor.

Clean energy advocates cheered the vote, which they said can help secure California's position as a world leader on clean energy and climate change policy.

"California has long been the home of big thinkers, innovators, and change-makers, and with SB100 we will be unleashing that entrepreneurial spirit to solve the existential challenge of climate change," Vote Solar executive director Adam Browning said.

Pacific Gas & Electric (PG&E), the state's largest utility, said lawmakers were moving too fast, too soon to shift completely to zero-carbon sources of electricity. The state's two other investor-owned utilities also opposed the bill.

"Lawmakers in the Assembly have put the cart before the horse, by approving a long-term procurement mandate that will affect utilities and their customers for more than 25 years, without any assurance that the state's utilities will remain financially stable and able to shoulder these new mandates in the face of growing wildlife risk," PG&E said.

SB 100 would also raise the state's renewable portfolio mandate to 60pc of electricity use by 2030, up from 50pc. It does not specify that renewables should be used to meet the final 2045 goal, but as California is due to shut down its last nuclear power plant within a few years, it is likely that the state will lean heavily on sources like wind and solar, along with energy storage.

The state already has one of the cleanest grids in the US, but it still relies on natural gas for about one-third of its electricity. That will have to be replaced as well for the state to meet the target.

California is aiming to cut its overall greenhouse gas emissions by 40pc from 1990 levels by 2030 and 80pc by 2050. Electricity accounts for about 16pc of the state's emissions.

California would be the second US state to adopt a 100pc clean energy goal. Hawaii set a 100pc by 2045 renewable energy mandate in 2015. But given California's position as one of the largest economies in the world, and the most populous US state, achieving a completely carbon free grid will be a much bigger task.

California's electricity sector produces about 15 times as much power as Hawaii's, according to US Energy Information Administration. That does not include imports from out-of-state generators, which accounted for about 29pc of California's electricity supply last year, according to state data.