Bill Gates' Breakthrough Energy backs 21 startups in new fellows cohort

While much of the world is focused on the power demands of AI data centers, Breakthrough Energy is paying attention for a different reason. “Data centers are a 10% bump against basically flat demand for electricity over the last 30 years. So it looks like a big bump, but data centers are absolutely the canary in the coal mine,” Eric Toone, managing partner at Breakthrough Energy Ventures, told TechCrunch. “You’re chasing a coming massive increase in demand for electricity.” That demand is forecast to surge as countries electrify entire sectors of their economies to cut carbon emissions — “electrifying everything implies a 3x increase in demand for electricity,” Toone said.

To help prepare for that future, Breakthrough Energy has spent the last several years supporting early-stage startups through its Fellows program. This year’s installment, its sixth, spans companies working on agriculture, nuclear fusion, robotics, and data center power efficiency; TechCrunch received an exclusive look at the incoming cohort. It is the first cohort announced since Ashley Grosh, who previously led the Fellows program, departed to become a partner at WovenEarth Ventures; senior director Benjamin Gaddy is serving as acting director while the organization determines what’s next, Toone said. Despite Grosh’s departure, the cohort still follows the program’s established formula. “We’re always right on the line that you’re not going to fund things that are silly, but the name of the game here is to take some big bets and hope to get some big payoffs,” Toone said.

Among the fellows is Borealis Fusion, pursuing fusion power using widely available proton-boron fuel that is challenging to heat to the temperatures fusion reactions require; another fusion startup, StarWarden, is working on heat management technology for future reactors. “If they can do it, you could get to much lower cost of energy,” Gaddy said of Borealis. Other startups — including Bedrock Semiconductor, K1 Semiconductor, and VariFlux — are working on squeezing more efficiency out of semiconductors and data centers; K1 is developing a more efficient method to process key materials including gallium nitride and silicon carbide. “You could reduce the cost of these power electronics by maybe 50%, maybe more,” Gaddy said.

Breakthrough Energy is also placing bets on agriculture and critical minerals, including molecular sensing to detect crop disease and robotics systems to harvest minerals from the ocean floor while minimizing disturbance, and is supporting startups such as AmHyTech and Ammovolt Energy that are developing ways to use and transport hydrogen with ammonia. “Hydrogen is the Swiss Army Knife of energy. If you have enough hydrogen, and importantly if it’s cheap enough, you can do anything,” Toone said, noting the infrastructure to move it doesn’t yet exist. This year’s fellows class also includes companies focused on climate adaptation rather than only decarbonization. “I think that folks really hoped that we were going to be able to decarbonize faster than we were able to,” Toone said. “It’s going to take longer and it’s going to be harder than we thought, and that absolutely leads you directly to adaptation.”

Why it matters

The cohort signals where a major climate-tech backer sees durable demand forming — power-hungry sectors like fusion, semiconductors, and data center efficiency — well beyond the current AI infrastructure buildout.