Google Signs Deal for Kairos Small Modular Reactors to Power AI Data Centers

Google is buying nuclear power from a fleet of small modular reactors to feed its artificial intelligence data centers. The technology giant has signed a first-of-its-kind agreement with California-based Kairos Power to deploy up to seven miniature reactors, aiming to secure 500 megawatts of continuous, carbon-free electricity by 2035.[1][3]

The move represents a structural shift in how the technology sector manages its physical infrastructure. As generative AI models and large language systems demand unprecedented volumes of electricity, wind and solar power—while clean—cannot guarantee the 24/7 baseload generation required to keep server farms running without interruption.[1][2]

To bridge this gap, Google is turning to small modular reactors (SMRs). Unlike conventional nuclear plants that generate upwards of 1,000 megawatts and take decades to construct, SMRs are defined as reactors with a maximum output of 300 megawatts.[1]

The core advantage of the SMR model is its manufacturing process. Instead of bespoke, on-site construction projects that are notorious for cost overruns and delays, SMRs are designed to be factory-built in standardized modules and assembled at their final destination.[1][3]

Kairos Power's specific approach diverges significantly from traditional water-cooled reactors. The company utilizes a molten salt cooling system paired with a specialized ceramic fuel known as TRISO.[2]

This Generation IV design operates at low pressure, which fundamentally alters the safety profile and reduces the need for the massive, expensive containment structures required by high-pressure light-water reactors. The molten salt efficiently transports heat to a steam turbine to generate electricity.[2][5]

Under the master development agreement, Kairos is tasked with bringing its first commercial reactor online for Google by 2030, with additional units rolling out through 2035.[3][4]

The theoretical framework of this partnership is already translating into physical grid integration. In August 2025, the Tennessee Valley Authority (TVA)—a federally owned utility—signed a power purchase agreement to become the first U.S. utility to buy electricity from a Generation IV reactor.[4][6]

This agreement centers on Kairos's Hermes 2 plant in Oak Ridge, Tennessee. Originally planned as a smaller demonstration unit, Kairos is boosting the output of a single reactor from 28 megawatts to 50 megawatts to accelerate the delivery of clean energy to Google's data centers in Tennessee and Alabama.[5][6]

The TVA deal establishes a three-party template for future deployments: a technology developer builds the reactor, a regulated utility integrates it into the regional grid, and a corporate off-taker guarantees the purchase of the power and its environmental attributes.[5][7]

This structure solves one of the most persistent hurdles in advanced nuclear development: financing. By stepping in as a guaranteed buyer, Google is effectively shouldering the financial risk of first-of-a-kind nuclear projects, allowing Kairos to advance down the manufacturing learning curve.[3][7]

Google is not navigating this transition in isolation. The entire hyperscaler industry is currently underwriting a nuclear renaissance to power the AI boom.[2][4]

Microsoft recently established a 20-year power purchase agreement with Constellation Energy that will restart a reactor at the Three Mile Island plant in Pennsylvania. Amazon has similarly executed multiple nuclear-focused deals, including agreements with Talen Energy and Energy Northwest.[1][5]

The urgency behind these investments is driven by stark projections regarding U.S. electrical infrastructure. Grid analysts forecast that domestic electricity demand will surge by nearly 16 percent by the end of the decade, propelled by the compounding requirements of data centers, domestic manufacturing, and broad electrification.[5]

Despite the influx of Silicon Valley capital, the SMR sector faces substantial skepticism. Critics point out that no commercial SMRs are currently operating in the United States, and the technology remains unproven at scale.[1]

A primary concern is the loss of economies of scale. Traditional nuclear plants offset their massive capital costs by generating enormous amounts of power; skeptics argue that smaller reactors may ultimately produce electricity at a higher levelized cost, negating their theoretical manufacturing advantages.[1]

Furthermore, navigating the U.S. Nuclear Regulatory Commission's approval process for novel reactor designs requires significant time and capital, though Kairos has already secured construction permits for its Hermes demonstration units.[6]

Ultimately, the Google-Kairos partnership represents a high-stakes wager on the future of energy infrastructure. If successful, it will not only secure the power required for the next generation of artificial intelligence but could also establish a commercially viable template for decarbonizing heavy industry worldwide.[3][7]