Some AI firms think nuclear power can help meet the electricity demand from Silicon Valley’s data centres, but building new nuclear power stations takes too long to plug the gap in the short term.
Silicon Valley wants to use nuclear power to support the energy-hungry data centres that help train and deploy its artificial intelligence models. But realistic timelines show that any US nuclear renaissance will have at best a limited impact during a period of fast-rising electricity demand.
 |
| The Three Mile Island Nuclear Generating Station in Pennsylvania, which closed in 2019 Michael Ventura/Alamy |
Global electricity usage from data centres is already on track to double by 2026. In the US, data centres represent the fastest-growing source of energy demand at a time when the country’s peak electricity demand is rising sharply. Meanwhile, the US government estimates that nuclear power’s share of overall US power generation will remain flat at best in the near future, partly because advanced nuclear reactor technologies remain years or decades away from commercial readiness.
“The share of nuclear energy in the power mix has held steady at about 20 per cent for decades, and future declines seem likely,” says Amanda Levin at the Natural Resources Defense Council, a non-profit based in New York. “While our models show that [growing demand for electricity] could result in the extension of operating licenses of many older reactors, there’s no sign that new reactors will be built anytime soon.”
Prospects are even more uncertain for the construction of advanced nuclear technologies, such as the small modular reactors that could act like mini nuclear power stations, or experimental fusion reactors. Several start-ups developing such technologies are backed by tech billionaires such as OpenAI co-founder Sam Altman and Microsoft co-founder Bill Gates. But none are likely to start operating commercially before 2030. By then, electricity demand from US data centres is expected to have doubled or even tripled relative to 2022. The data centres will potentially use as much electricity as 40 million US houses.
“New technologies like small modular reactors will not be able to contribute at all to data centres by 2030, and it’s really doubtful that they’ll be able to contribute much by even 2040,” says Allison Macfarlane at the University of British Columbia in Canada, a former chairperson of the US Nuclear Regulatory Commission, an independent agency of the US government. She also questions if nuclear power can prove cost-competitive with cheaper renewable power and improved energy storage technologies.
Tech companies are also looking to renewables and batteries to reduce their carbon emissions. But major US utilities are already planning to build more natural gas plants and delay retirement of coal plants to meet electricity demand.
Conventional nuclear plants can still play a role in the short term, says Adam Stein at the Breakthrough Institute, a research centre in California. Stein says that companies such as Amazon and Microsoft are buying data centres located next to existing nuclear power plants or seeking to purchase a stable electricity supply from nuclear plants at fixed prices. Developers are also proposing to build massive data centres co-located with nuclear plants.
As a proponent for both nuclear power and renewable power, Stein argues that advanced nuclear technologies will be important for meeting electricity demand growth beyond 2030 – especially in providing more jobs than comparable renewable technologies, to soften the economic blow of job losses as coal plants are shut down.
But he acknowledges the uncertainties surrounding the timeline for more experimental bets such as fusion power. “Fusion still needs to achieve one or more breakthroughs in the engineering, and you can’t schedule a breakthrough,” says Stein.