In a letter to California governor Edmund Brown, a group of climate scientists have urged him to ask the California Public Utility Commission to delay consideration of any proposal to close the two-unit Diablo Canyon NPP. They say there are “serious questions” about whether the planned closure is good for ratepayers, the environment and the climate and say any decision should only be taken after the legislature and the public openly debate how California can most quickly and cost-effectively stop damage to the climate from electrical system emissions. Utility Pacific Gas and Electric (PG&E) earlier agreed in a joint proposal with Friends of the Earth, the Natural Resources Defence Council, the Alliance for Nuclear Responsibility and other groups to close the station in 2025, after its current operating licences expire in November 2024 and August 2025. The Diablo Canyon units began commercial operation in 1985 and 1986.
The scientists said: “Retirement of the plant will make a mockery of California’s decarbonisation efforts. Diablo Canyon’s yearly output of 17,600 gigawatt-hours supplies 9% of California’s total in-state electricity generation and 21% of its low-carbon generation. If Diablo Canyon closes it will be replaced mainly by natural gas, and California’s carbon dioxide emissions will rise.” They said the joint proposal does not come close to replacing this lost low-carbon power. It only mandates 4,000GWh a year of energy efficiency and, optionally, new renewable generation, to replace four times the amount of lost nuclear output. “And much of the demand reduction PG&E forecasts to replace Diablo will come about simply from customers switching from PG&E to alternate electricity providers, with no guarantee that their new electricity supply will come from low-carbon sources,” the scientists said.