California Votes to Require 100% Clean Electricity by 2045

California lawmakers approved a measure mandating that all electricity come from wind, solar and other clean-energy sources by 2045, marking the state’s biggest step yet in the fight against global warming.

The state Assembly voted 43-32 in favor of the legislation Tuesday. It would eliminate the reliance on fossil fuels to power homes, businesses and factories in the world’s fifth-largest economy, accelerating a shift already under way. The state currently gets about 44 percent of its power from renewables and hydropower.

“It’s already happening for economic reasons,” said Pavel Molchanov, an analyst at Raymond James Financial Inc., who noted that solar and wind are the cheapest sources of electricity in some regions. “I think California can get to 100 percent in 15 years.”

California has positioned itself to lead the battle against climate change by cutting emissions even as the Trump administration has worked to roll back the state’s stringent auto pollution standards and prop up ailing coal-fired power plants. Earlier this year, California became the first U.S. state to mandate solar rooftop panels on almost all new homes. It would be the second state to require 100 percent carbon-free power after Hawaii.

“This is landmark legislation that is helping to stave off some of the worst effects of climate change,” said Dan Jacobson, state director for Environment California, an environmental advocacy group. “We need it more than ever because the state and the world are starting to see the devastating impacts of climate change.”

The move would accelerate a shift already under way to wind and solar but hinges on a big bet — that battery costs will plunge, allowing for a transition away from the natural gas plants that provide about a third of California’s electricity.

Pending Approvals

The bill must clear the state Senate — which had already approved an earlier version of the measure — before heading to Governor Jerry Brown, who is expected to sign it into law. The legislature adjourns at the end of the week.

Proponents of the bill say solar and wind energy already compete in price with fossil fuels and that costs are expected to decline further. But they also note that the measure allows for a mix of clean-energy resources, including large hydroelectric dams.

To read about how California needs more batteries to meet its goal, click here.

Opponents — including the state’s investor-owned utilities run by PG&E Corp., Edison International and Sempra Energy — raised concerns that the requirement would raise electricity costs. California would need to install more than 200 times as much energy-storage capacity than it has now to make up for the loss of gas plants, according to the Clean Air Task Force, a Boston-based energy-policy nonprofit.

“When it comes to fighting climate change and reducing our reliance on fossil fuels, California won’t back down,” the bill’s sponsor, California state Senator Kevin De Leon said. “We have doubled down.”