Scientists and engineers from Stanford University and the Massachusetts Institute of Technology claim in a new report that delaying retirement of the Diablo Canyon nuclear power plant in San Luis Obispo County, Calif., by a decade until 2035 would reduce carbon emissions from state utilities by more than 10% and save $2.6 billion in power costs.

With accelerating effects of climate change, issues facing California “compel a reassessment” of the closure plan, researchers say. The 2,240-MW two-unit plant, which began operating in the mid 1980s, can remain economic for the foreseeable future, they said. 

Using it for desalination also could also increase fresh water in the state for a significantly lower cost than other methods, the academics said.

A settlement was approved in 2018 to permanently close the plant in 2025, before a California law required it to supply all power from zero-carbon sources and before an executive order directed the state to become climate neutral by 2045. Diablo Canyon, owned by utility PG&E, supplies 15% of California’s carbon-free electricity.

Developer Hydrostor on Nov. 23, meanwhile. submitted an application to the state to develop a 400-MW compressed air energy storage facility in San Luis Obispo Country, which it said could, as the nuclear plant closes, reliably generate clean energy for at least eight hours daily when it comes on line in 2026 or 2027.

Pecho Energy Storage Center, with an estimated investment of about $800 million,. will be built, owned, and operated by Pecho LD Energy Storage, a joint venture between Toronto-based Hydrostor and French asset manager Meridiam Infrastructure Partners.

But rsearchers contend that the Diablo Canyon nuclear units also could power a carbon-free hydrogen plant at half the cost of production from wind or solar to help meet growing demand for zero-carbon fuels, the report says.

The cost would be about equal to current hydrogen produced from natural gas with carbon capture. Extending the plant operating license to 2045 would reduce the need for 18 GW of solar power to meet state requirements and spare 90,000 acres of land needed for its production, the researchers said. Approval to build desalination and hydrogen production plants would be needed. 

PG&E says it must follow state energy policies, with the California Public Utilities Commission. and state legislature approving the plant closing. Stakeholders also were part of the closure settlement.

“Our focus remains on safely and reliably operating the plant until the end of its licenses that expire in 2024 and 2025,” a PG&E spokesman told ENR. David Weisman, legislative director for the Alliance for Nuclear Responsibility says extending the plant’s life is not an option.