Diablo Canyon Nuclear Units to Shutter: What Are the Consequences?

diablo canyon nuclear plantThis week, the Institute for Energy Research released an analysis on the consequences of Pacific Gas and Electric’s (PG&E) decision to shutter two Diablo Canyon nuclear units in 2024 and 2025. PG&E plans to replace the nuclear units with intermittent wind and solar energy, an endeavor that could cost billions and increase carbon dioxide emissions.

In their infatuation with wind and solar energy, PG&E and the state of California are making decisions that will prove costly to energy consumers.

Key considerations include:

  • Diablo Canyon produces 9 percent of California’s electricity and 20 percent of Pacific and Gas and Electric’s power. The Nuclear Regulatory Commission indicates that the Diablo Canyon units are well run and among the best in the country. The utility indicates that they are able to withstand earthquakes, tsunamis and flooding.
  • Decommissioning Diablo Canyon is expected to cost $3.8 billion and replacing all its power with solar energy could cost $15 billion based on current prices.
  • PG&E is expecting to only need to replace half of Diablo Canyon’s power, 9,000 gigawatt-hours. The utility expects to get 2,000 gigawatt-hours from improved energy efficiency by 2025, leaving a gap of 7,000 gigawatt-hours that it is expecting to fill with wind and solar power. However, when nuclear plants have been shuttered thus far, their energy has been replaced almost entirely by natural gas.
  • Natural gas consumption could increase by 34 percent in northern California between 2023 and 2026 when Diablo Canyon is shuttered despite the company’s renewable energy and efficiency goals. Some have estimated that the carbon dioxide emissions from the replacement power are equivalent to putting 2 million cars on the road.


Only California would consider closing a perfectly good nuclear plant that emits no carbon dioxide emissions and replace it with intermittent renewable energy that needs back-up power from a flexible fuel such as natural gas.

California’s laws to get 50 percent of its electricity from renewable energy and to double its energy efficiency‚Äìboth by 2030‚Äìare driving these decisions that will prove costly for electricity consumers in the state.

Click here to read the full analysis.