(Bloomberg) -- California faces an energy gap as it transitions to a clean-powered economy by 2045 and must leave all options on the table until then — including nuclear, according to the state’s top air regulator.

“Cost obviously is a big factor, waste is a big factor, the permitting challenges are a big factor,” Liane Randolph, chair of the California Air Resources Board, said during an interview at the Bloomberg office in San Francisco. “But I don’t think we should prematurely cross anything off the list,” she said in response to a question about whether she supports keeping nuclear power as part of California's energy mix.

The California Air Resources Board, or CARB, is the state’s most powerful agency in charge of implementing its ambitious climate policies, including cutting carbon emissions down to nothing over the next two decades.

Read More: California’s Fear of Blackouts Blocks Goal of Fossil-Free FutureUnder the leadership of Randolph, who was appointed by Governor Gavin Newsom in late 2020, CARB has passed a series of controversial rules that aim to reduce emissions from the transportation sector, the state’s largest source of carbon pollution. These include banning the sale of new gasoline-powered cars by 2035, requiring truck manufacturers to accelerate the sales of zero-emission models and mandating ride-hailing companies such as Uber Technologies Inc. and Lyft Inc. increase their share of electric vehicles.Despite being a vocal advocate for fighting climate change and reducing fossil fuel dependence, Newsom faces a dilemma as the state’s power grid struggles to meet demand during extreme weather. Over the past year, Newsom has supported extending the operations of three natural gas plants in Southern California and the state's last nuclear plant, arguing they are necessary stopgap solutions to ensure grid reliability and avoid blackouts.Though nuclear power plants don’t generate greenhouse gases, environmentalists cite concerns over the radioactive waste they produce. And California’s only nuclear power plant, Diablo Canyon, sits near several fault lines — a big concern in the earthquake prone state.

For California to be successful in the clean energy transition, the state needs to keep pushing the policies it’s set in place, Randolph said. Some of the air board's biggest priorities this year are strengthening the Low Carbon Fuel Standard, which aims to slash emissions in transportation fuels, and the state's cap-and-trade program, which critics say has been ineffective at helping meet the state’s goal.

“From a policy standpoint, we know where we need to go,” Randolph said. “We just need to get it moving.”

(Updates with comments from Randolph seventh paragraph.)

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