Diablo Canyon, California’s last remaining nuclear facility, will be retired within a decade if state regulators agree to a proposal by Pacific Gas and Electric Corporation and several environmental and labor organizations to replace its power production with clean energy.

The San Francisco-based utility said on Tuesday that it will ask state regulators to let operating licenses for two nuclear reactors at its Diablo Canyon power plant expire in 2024 and 2025. The utility said it would make up for the loss of power with a mix of energy efficiency, renewables and energy storage that would cost less than nuclear power.

“This is a new green yardstick for replacing every fossil fuel and nuclear plant in the world,” said S. David Freeman, a senior advisor with Friends of the Earth’s nuclear campaign, one of several groups making the announcement. “It’s not only cleaner and safer, but it’s cheaper.”

The Diablo nuclear power plant is one of many closing or scheduled to close around the country, but is the first with a commitment from a public utility not to increase carbon emissions when making up for the lost energy.

The proposal comes as the share of solar and wind power in California’s energy mix is rapidly increasing. In 2014, nearly 25 percent of retail electricity sales in California came from renewable sources. Utilities are bound by the state’s renewable portfolio standard policy to increase their share of electricity from renewables to 50 percent by 2030.

PG&E said it would exceed the state mandate, raising its renewable energy target to 55 percent by 2031 as part of its proposal to close Diablo Canyon.

“California’s energy landscape is changing dramatically with energy efficiency, renewables and storage being central to the state’s energy policy,” PG&E chairman, chief executive and president Anthony Earley said in a statement. “As we make this transition, Diablo Canyon’s full output will no longer be required.”

As renewables ramp up, California is also using less energy. Legislation passed last September requires public utilities to double energy efficiency targets for retail customers by 2030. The policy is expected to reduce the state’s electricity needs by 25 percent in the next 15 years.

The Natural Resources Defense Council, which co-signed the joint proposal, estimated PG&E customers would save at least $1 billion.

“Energy efficiency and clean renewable energy from the wind and sun can replace aging nuclear plants—and this proves it,” NRDC president Rhea Suh wrote in a statement. “Nuclear power versus fossil fuels is a false choice based on yesterday’s options.”

Not everyone, however, agreed this was progress.

“When nuclear [facilities] have closed in the last few years, they’ve been replaced by fossil fuels, and Diablo Canyon will be no different,” said Jessica Lovering, energy director for the Breakthrough Institute, a proponent of nuclear power as a key provider of carbon-free power. “The plant currently provides 8 percent of California’s electricity and over 20 percent of its low-carbon electricity, the loss will most certainly be made up of increased natural gas burning or increased imports from out-of-state.”

The proposal to close the Diablo plant comes on the heels of a number of nuclear facility closures nationwide, including the shuttering of the San Onofre plant in California in 2013 and recent closures in Florida, Wisconsin and Vermont.  The Fort Calhoun nuclear power plant in Nebraska is scheduled to close later this year and additional closures in New York, Illinois, Massachusetts and New Jersey are planned in coming years.

The closure and replacement of Diablo Canyon with a mix of renewables, energy storage and increased energy efficiency is a breakthrough and shift from “20th century thinking,” Freeman said. “Modern day Edisons have invented better technology.”