Microsoft's groundbreaking deal to revive Three Mile Island for AI power

Tech giant partners with Constellation to restart iconic nuclear plant, signaling shift in energy landscape for AI development.

Microsoft's groundbreaking deal to revive Three Mile Island for AI power
Three Mile Island

On September 20, 2024, Microsoft and Constellation Energy announced a landmark agreement to resurrect the shuttered Three Mile Island nuclear power plant in Pennsylvania. This unprecedented deal, aimed at powering Microsoft's data centers for artificial intelligence operations, marks a significant shift in the energy landscape and highlights the growing demand for reliable, carbon-free electricity in the tech industry.

According to the New York Times, Constellation Energy plans to invest $1.6 billion to revive the iconic nuclear facility, which has been dormant since its closure in 2019. The agreement stipulates that Microsoft will purchase as much power as possible from the plant's 880-megawatt reactor over a 20-year period, with prices rumored to exceed $100 per megawatt-hour.

Three Mile Island, infamous for its partial meltdown in 1979, ceased operations five years ago due to competition from cheap fossil fuels and a lack of interest from tech companies in purchasing its electricity for clean energy initiatives. The plant's planned restart, scheduled for 2028, represents a dramatic reversal in the fortunes of nuclear power and its role in supporting the burgeoning AI industry.

Mark Nelson, an energy analyst, emphasized the significance of this deal, stating, "Clearly, the biggest tech companies are desperate to buy up nuclear plants. This deal between Microsoft and Constellation represents the biggest and richest of its kind. It won't be the last."

The resurgence of interest in nuclear power for AI applications stems from the unique energy requirements of large-scale data centers. Yann LeCun, Chief AI Scientist at Meta, explained, "AI data centers will be built next to energy production sites that can produce gigawatt-scale, low-cost, low-emission electricity continuously. Basically, next to nuclear power plants."

LeCun highlighted the advantages of this approach, noting, "The advantage is that there is no need for expensive and wasteful long-distance distribution infrastructure." He also pointed out the limitations of renewable alternatives, stating, "Solar and wind are nice and all, but they require lots of land and massive-scale energy storage systems for when there is too little sun and/or wind. Neither simple nor cheap."

The shift towards nuclear power for AI operations is driven by several factors:

  1. Electricity demand: AI data centers require hundreds of megawatts of power in a single location, most of the time.
  2. Cost efficiency: The capital cost of power infrastructure represents only a small fraction (approximately 3%) of the total capital expenditure for compute resources in AI data centers.
  3. Grid constraints: Obtaining grid interconnections for large power draws can take multiple years, creating bottlenecks for AI development.
  4. Reliability: Nuclear power plants offer high availability, with some estimates suggesting they operate 98% of the time when expected to be online.

This trend extends beyond Microsoft, with other tech giants exploring various energy technologies to support their AI initiatives. Danielle Fong, a physicist and entrepreneur, noted that companies are considering a range of options, including:

  • Conventional, large nuclear fission
  • Small modular nuclear reactors
  • Engineered geothermal systems
  • Fusion technology
  • Stirling engines

The revival of Three Mile Island and the broader shift towards nuclear power for AI applications have sparked debates about energy equity and technological priorities.

The deal also raises questions about the future of energy policy and infrastructure development. Will Shackel, another commentator, warned, "Australia is seriously going to get left behind if we don't lift the ban quickly," referring to restrictions on nuclear power in some countries.

As the AI industry continues to grow, its energy demands are reshaping the power generation landscape. The Microsoft-Constellation deal for Three Mile Island may be just the beginning of a new era in which tech companies play a more direct role in energy production and distribution.

Key facts

  • Agreement announced: September 20, 2024
  • Investment by Constellation: $1.6 billion
  • Three Mile Island reactor capacity: 880 megawatts
  • Contract duration: 20 years
  • Estimated power price: Over $100 per megawatt-hour
  • Planned restart date: 2028
  • Original closure date: 2019
  • Date of Three Mile Island accident: 1979