Investment is pouring in as the hype around nuclear fusion grows

• Tech leaders are betting on nuclear power as a key source of clean energy in the next decade.
• AI tech companies are building small nuclear fission plants to power their data centers.

Tech executives are rallying around nuclear energy to fuel the demands of the AI revolution.

From Amazon to Google, tech giants at the forefront of the AI boom are investing in companies building nuclear reactors and forming partnerships with energy providers to power their data centers.

Many of these companies are generating energy through nuclear fission, which involves splitting atoms from elements like uranium and plutonium to release energy. It's cleaner than fossil fuels and more reliable than solar. But fission can release harmful radioactive waste that needs to be disposed of safely and mining uranium can have deleterious effects on the environment.

The solution, in the view of a growing number of leaders in the tech industry, is nuclear fusion, which involves fusing the nuclei of two atoms to release energy. It's considered a safer method because it releases less radioactive waste and greenhouse gases.

Microsoft cofounder Bill Gates distilled the differences between fission and fusion on a recent episode of the Possible podcast. Fission, he said, is "where you take the big atoms like uranium, and as they split, you get energy." Fusion occurs when "you take the small atoms, primarily hydrogen, and as you put them together, you release energy."

Scientists have proven that nuclear fusion is feasible. Experiments at the National Ignition Facility in California over the last year, for instance, hit a milestone when they generated more energy than what was used. Fusion plants, in theory, could produce almost 4 million times as much energy as burning coal or oil — without carbon emissions. However, there are still obstacles to it becoming a widespread energy source.

Tritium, one of the hydrogen isotopes used in fusion reactions, is rare and expensive. It also has radioactive properties. Another challenge is that fusion requires extremely high temperatures, as high as the "center of the sun, millions of degrees," Gates said.

AI tools are now helping to make fusion a reality. Commonwealth Fusion Systems, in which Gates is an investor, is on track to have a system for fusion in 10 years, he said.

"But at some point, fusion energy will be extremely cheap, and it doesn't have the same waste problems that fission does," he said.

Gates, who is also an investor in another nuclear fusion company called Pacific Fusion — which launched in 2023 and announced a more than $900 million Series A funding round this month — believes supporting nuclear will help reduce clean energy costs.

"We, society as a whole, even though a lot more money is coming into it, we're still under-investing in fission and fusion, given that the value of cheap electricity specifically is so fundamental to society," he said.

Venture firm General Catalyst led the funding round for Pacific Fusion, which included participation from Gates's climate solutions investment fund, Breakthrough Energy Ventures, and individual investors like Citadel founder Ken Griffin, Stripe cofounder Patrick Collison, venture capitalist John Doerr, and Mustafa Suleyman, the head of Microsoft AI.

Other veterans in the industry are betting on an even shorter timeline for fusion technology to become a reality.

At TechCrunch Disrupt this week, venture capitalist Vinod Khosla said, "I'll take a bet with anybody, five years from now, we won't be talking about whether fusion is real or not."

He said he hopes that by then fusion will be proven as an economic possibility. "They're engineering all the systems to go directly into production without having to first prove the technology and then do the engineering," he said.