They plan to restart the Three Mile Island nuclear power plant to power Microsoft’s cloud and AI data centers.
If all goes according to plan, a nuclear reactor at the famous Three Mile Island nuclear power plant in Pennsylvania – the site of a serious accident in the 1970s – will be restarted by utility company Constellation Energy to fulfill an agreement with Microsoft to supply its data centers with carbon-free electricity.
The reactor that is coming back online is not the one that suffered a meltdown in 1979 and has been shut down since the accident. That was TMI Unit 2. The neighboring reactor, TMI Unit 1, came back online in 1985 and continued to operate until 2019, when it was shut down due to “lack of economic viability,” according to Constellation.
After remediation and obtaining the necessary federal and state permits, Constellation hopes to have TMI Unit 1 operational by 2028. The company says restarting the reactor will “add approximately 835 megawatts of carbon-free energy to the grid.” It will also rename the plant the Crane Clean Energy Center after Chris Crane, a nuclear energy titan who died earlier this year.
Both Pennsylvania politicians and the U.S. Department of Energy have praised Constellation’s plan. Dr. Michael Goff, deputy secretary of the state’s Office of Nuclear Energy, said that “permanent, carbon-free nuclear energy plays an important role in combating climate change and meeting the nation’s growing energy needs.”
Microsoft’s data centers are the infrastructure that supports the company’s cloud storage and compute services, including its new and notoriously energy-hungry AI processing. Bobby Hollis, Microsoft’s vice president of energy, says this power deal, the largest the company has ever signed with Constellation, is a “major milestone in Microsoft’s efforts to decarbonize the power grid.” Regardless, we know Microsoft has considered using “small modular reactors” and “microreactors” to power its data centers.
Microsoft founder Bill Gates is also active in the nuclear energy business: TerraPower, the company he founded in 2006, began building a new power plant in Wyoming earlier this year.
“The U.S. hasn’t needed a lot of new electricity to date — but with the advent of a variety of things, from electric cars and buses to electric heat pumps to heat homes, the demand for electricity is going to increase a lot,” Gates told NPR in June. “And now these data centers are contributing to that. So the big tech companies are looking for ways to provide more electricity so that these data centers can meet the exploding AI demand.”