Microsoft to Revive Three Mile Island Nuclear Plant to Power AI Data Centers

Unit 1 of Three Mile Island in the foreground emitting water vapor in 2019, prior to shutdown. Photo by Constellation Energy CC BY-SA 4.0, https://commons.wikimedia.org/

Microsoft has signed a 20-year agreement with Constellation Energy to secure a stable supply of carbon-free power for its data centers. The deal, announced in September 2024, revives Unit 1 at the Three Mile Island nuclear facility in Pennsylvania, which had been shut down in 2019 due to economic challenges. This move marks a significant step in Microsoft’s effort to meet its sustainability goals, as the company grapples with the increasing energy demands driven by its expanding artificial intelligence infrastructure.

“As part of our commitment to support a more sustainable future and become a carbon-negative company, we’re dedicating significant resources to advancing this goal and adding carbon-free electricity and capacity in the grids where we operate,” said Bobby Hollis, Microsoft’s Vice President of Energy.

The Three Mile Island plant, known for its partial meltdown in 1979, will undergo a major overhaul to bring Unit 1 back online.

Constellation Energy plans to invest $1.6 billion in the project, which will generate 835 megawatts of electricity once operational in 2028. The plant will supply clean energy for Microsoft’s data centers in key locations like Virginia, Ohio, and Pennsylvania, where the company is expanding its cloud computing network to meet AI demands.

A Carbon-Free Commitment

This partnership forms part of Microsoft’s broader goal to become carbon-negative by 2030. While the company has made strides in renewable energy, the growing power consumption from its AI and cloud operations has increased emissions. Earlier this year, Microsoft reported a 30% rise in emissions since 2020, underscoring the challenge of balancing technological progress with environmental responsibility.

Boosting Jobs and the Economy

In addition to fulfilling energy demands, the Three Mile Island restart will have a significant economic impact. The project is expected to create around 3,400 direct and indirect jobs, while generating over $3 billion in state and federal taxes. It is also expected to contribute $16 billion to Pennsylvania’s GDP, providing a substantial boost to the local economy.

“Before it [Unit 1 at Three Mile Island] was prematurely shuttered due to poor economics, this plant was among the safest and most reliable nuclear plants on the grid, and we look forward to bringing it back with a new name and a renewed mission to serve as an economic engine for Pennsylvania,” said Joe Dominguez, president and CEO of Constellation.

The facility will be renamed the Crane Clean Energy Center, honoring Chris Crane, Constellation’s former CEO and a long-time advocate for nuclear energy – Crane passed awat earlier this year at the age of 65.

Overcoming Challenges

Restarting the plant won’t be without challenges. Constellation must secure approval from the U.S. Nuclear Regulatory Commission and other regulatory agencies to ensure the plant meets all safety and environmental standards. The company also needs to upgrade key infrastructure, such as turbines and cooling systems, to bring the plant back online.

Despite these hurdles, the project seems to have strong public support in Pennsylvania. “According to a recent statewide poll, Pennsylvanians favor restarting the plant by a more than 2-1 margin,” Dominguez said. This growing support for nuclear energy stems from its potential to provide reliable, carbon-free power and play a crucial role in combating climate change.

The Crane Clean Energy Center is an example of how industries are rethinking their approach to sustainability. Nuclear energy, once viewed with skepticism, is now becoming a key player in powering this new energy-guzzling AI age.

For Microsoft, this collaboration represents a vital step toward achieving its climate goals while meeting the growing demands of AI innovation.