California is reversing course on nuclear power, with state officials now pushing to keep Diablo Canyon operating through 2045 instead of shutting it down in 2025, driven largely by soaring electricity demand from artificial intelligence data centers and electric vehicles. The shift reflects a broader national trend where aging nuclear plants are being restarted or extended to meet the power-hungry needs of AI infrastructure, even as the state pursues its mandate to reach 100% clean energy by 2045.

Why Is California Suddenly Keeping Its Last Nuclear Plant Open?

A decade ago, Pacific Gas and Electric (PG&E), the operator of Diablo Canyon, agreed to methodically shut down the plant's reactors in 2025. But as that deadline approached, state officials, including Governor Gavin Newsom, reversed course. They first extended the plant's life to 2030, and now a growing coalition of nearly 50 groups is pushing for an extension all the way to 2045.

The reason is straightforward: California faces an unprecedented collision between two competing demands. The state must increase electricity generation by roughly 50% through 2045 to power AI data centers, electric vehicles, and building electrification, while simultaneously achieving 100% carbon-free electricity by that same year. Diablo Canyon, which consistently provides up to 9% of California's electricity with zero greenhouse gas emissions, has become seen as essential to bridging that gap.

"We have an abundance of renewables, and we're doing good with procurement, but the sun sets, the wind doesn't blow, and that's where reliability and stability come into question," said Conor Doyle, chief of strategic initiatives at PG&E.

Conor Doyle, Chief of Strategic Initiatives at Pacific Gas and Electric

The challenge is that California's renewable energy portfolio, while impressive, cannot yet provide the round-the-clock power that Diablo Canyon delivers. The state has surpassed 21,000 megawatts of battery storage capacity, the largest fleet in the nation, and used more solar than natural gas during the first half of 2026 for the first time. Yet there remains a critical gap: no always-on, carbon-free power sources are currently in the interconnection queue to replace Diablo's baseload capacity.

How Does This Fit Into a Broader National Trend?

California's nuclear reversal is not an isolated decision. Across the United States, aging nuclear plants are being extended or restarted specifically to power AI data centers. Three Mile Island in Pennsylvania, the site of the worst commercial nuclear accident in U.S. history, is slated to reopen in 2027 as part of a 20-year deal to power Microsoft data centers. The Duane Arnold plant in Iowa will start back up in 2029, nine years after its closure, to help power data centers for Google.

This national pivot underscores how AI infrastructure has become a primary driver of energy policy. Data centers require massive, continuous power supplies, and nuclear energy offers a carbon-free solution that renewables alone cannot yet provide at the necessary scale and consistency.

What Are the Key Challenges to Extending Diablo Canyon?

Opponents of the extension raise legitimate concerns about keeping the plant operational into its seventh decade:

• Aging Infrastructure: Diablo Canyon was built in the 1980s, and extending operations to 2045 would make the plant 60 years old, raising questions about the structural integrity of aging reactors and equipment.
• Nuclear Waste Storage: Spent nuclear fuel is stored in lead and stainless steel casks bolted into concrete at a specially built pad at Diablo, and extending operations means 15 more years of waste accumulation with no permanent disposal solution in sight.
• Seismic Risk: Diablo Canyon sits on the Central Coast near active fault lines, and critics argue that operating an aging reactor in an earthquake-prone region poses unacceptable risks to nearby communities.
• Renewable Energy Concerns: Some environmental advocates worry that extending nuclear operations could reduce political and financial incentives to accelerate renewable energy deployment and grid modernization.

Local opponents, many of whom live near the plant, view the extension as the latest in a series of broken promises. They point out that the original agreement to shut down Diablo was itself a compromise reached after decades of activism.

What Do Energy Experts Say About California's Options?

Energy analysts acknowledge that the math has shifted dramatically since California first committed to a nuclear exit. Replacing Diablo Canyon with clean energy may have looked feasible in 2016, but the challenge has grown more complex as electricity demand has surged and the state approaches its 2045 clean energy deadline.

"The question of how California is going to make major emissions reductions while keeping electricity affordable and reliable starts in the 2030s and goes all the way to 2045. Shutting down Diablo in the middle of all that was always going to be a stretch," explained David Victor, a professor of innovation and public policy at UC San Diego.

David Victor, Professor of Innovation and Public Policy at UC San Diego

One critical gap in California's clean energy strategy is offshore wind power. The state had aimed for 2 to 5 gigawatts of offshore wind by 2030, but none has yet been built. Political opposition has slowed development, and the Trump administration recently struck deals with three of California's offshore wind leaseholders to walk away from their plans and instead invest in fossil fuel projects.

Steps to Understanding California's Energy Future

• Track Legislative Action: Extending Diablo Canyon through 2045 requires an act of the California Legislature, and Governor Newsom has deferred the decision to the next administration. Monitor state legislative sessions for proposed bills on nuclear extension.
• Monitor Federal Licensing Decisions: The Nuclear Regulatory Commission renewed Diablo's federal operating license in April 2026, technically permitting operations until 2045. Watch for any regulatory changes or safety reviews that could affect the plant's future.
• Follow Renewable Energy Deployment: Pay attention to California's progress on battery storage, solar capacity, and offshore wind projects, as these will determine whether the state can eventually replace Diablo's baseload power with clean alternatives.
• Observe AI Data Center Growth: Track announcements of new AI data center projects in California and their power requirements, as these will directly influence the state's electricity demand forecasts and energy policy decisions.

The Diablo Canyon debate ultimately reflects a fundamental tension in America's energy transition. AI data centers are driving unprecedented electricity demand, and the nation's grid must simultaneously decarbonize. Nuclear power, once viewed as a relic of the past, has become a critical tool for meeting both goals. Whether California can thread this needle by extending Diablo while accelerating renewable deployment remains an open question, but the decision will likely shape energy policy across the country.