Alphabet Inc.’s Google is investing in the development of the next generation of nuclear power, backing a company that’s building small modular reactors and agreeing to purchase energy once the sites start supplying US grids.

Google signed an agreement with Kairos Power to construct a series of so-called SMRs that use molten-salt cooling technology. The move is part of an effort to bring online new carbon-free electricity as the company builds out data centers in the next decade, said Michael Terrell, senior director of energy and climate at Google. Power supplies are expected to start between 2030 and 2035.