Google is betting on not one, but two nuclear technologies to keep the lights on at its data centers. The company has partnered with both Kairos Power and GE Vernova in a hedged bet on the future of small modular reactors.
The partnership with Kairos Power, announced in October 2024, targets up to 500 MW of capacity by 2035, using fluoride salt-cooled high-temperature small modular reactors — compact nuclear plants that use molten salt instead of water to transfer heat.
The Kairos deal and its fluoride salt-cooled future
The centerpiece of the Google-Kairos collaboration is the Hermes 2 demonstration project. Originally designed with 28 MW of output, the project got a significant upgrade in August 2025 when Google, Kairos, and the Tennessee Valley Authority signed a tri-party power purchase agreement that scaled Hermes 2’s capacity to 50 MW.
That PPA is structured to deliver power to Google facilities in Tennessee and Alabama, with commercial operations targeted for 2030.
