Breakthrough Energy backs 21 early-stage bets on the future of power.

Breakthrough Energy has selected multiple early-stage climate-tech companies for the sixth cohort of its Fellows program, backing technologies ranging from nuclear fusion and more efficient data centers to hydrogen transport, critical minerals and climate-resilient agriculture.

The program, founded as part of Bill Gates’ climate initiative, is not a conventional venture-capital round. Fellows can receive up to $500,000 in R&D funding plus as much as $500,000 in technical and other in-kind support, alongside mentorship and access to Breakthrough Energy’s network. The goal is to help risky technologies move from laboratory research toward commercial deployment.

Electricity demand is a major theme this year. Eric Toone, managing partner at Breakthrough Energy Ventures, argues that today’s concerns over AI data centers are only an early indication of a much larger challenge. Electrifying transport, buildings and industry to replace fossil fuels could ultimately increase electricity demand far more dramatically. Several selected companies target that problem directly.

Bedrock Semiconductor, K1 Semiconductor and VariFlux are developing technologies intended to make semiconductors and data centers more efficient. K1 is working on improved processing methods for materials such as gallium nitride and silicon carbide, which Breakthrough Energy says could substantially reduce the cost of power electronics. Other projects are considerably more speculative. Borealis Fusion is pursuing proton-boron fusion, an approach that could produce attractive fusion energy if researchers can overcome the extreme temperatures required. StarWarden is developing heat-management technology for future fusion reactors.

Hydrogen is another focus. AmHyTech and Ammovolt Energy are exploring ammonia as a way to store or transport hydrogen more practically, addressing the lack of dedicated hydrogen infrastructure. Breakthrough Energy is also supporting technologies for detecting crop diseases and Mithril Minerals’ robotic approach to recovering critical minerals from the ocean floor with less disturbance.