A “holy grail” breakthrough. The “biggest news of the decade.” Potentially “limitless clean energy.”
Those were the headlines that circulated the globe in December 2022, after fusion scientists at the Lawrence Livermore National Lab reported they achieved fusion ignition for the first time in history — creating more energy that it took to start the reaction. The team, led by Dr. Annie Kritcher, has since repeated it more than 10 times; in April, a reaction produced a record four times its energy input.
The breakthrough put Kritcher at the top of the invite list for business conferences and lavish parties alike, including those hosted by Hollywood A-listers and billionaires. A chance meeting at one such gathering paved the way for the scientist’s next act: the December 2025 founding of Inertia, a company that aims to bring fusion ignition out of the lab and into an actual power plant.
Kritcher, after delivering a presentation about her work at LLNL, was approached by Jeff Lawson, a billionaire entrepreneur who made his fortune as co-founder and former CEO of the cloud communications platform Twilio. Lawson offered his congratulations, and said he assumed Kritcher’s team was working with commercial developers or another fusion company to bring their technology to market.
To his surprise, that wasn’t the case, at least not yet. The two got to work, and brought on a third co-founder to help. Dr. Mike Dunne, Inertia’s chief technology officer, was a photon science professor at Stanford University who had led an international initiative on how to design utility-scale fusion plants, and connected to the team via his wife, who taught Kritcher’s daughter in elementary school.
With its launch, Inertia became the only fusion company with a team of scientists who’ve publicly proven ignition is possible. Now, they aim to build a utility-scale power plant within the next decade by solving some big problems: the enormous cost of building powerful laser systems and a virtually non-existent manufacturing base.
Building a fusion power plant
Nuclear fusion is the reaction that powers the sun and the stars. In order to recreate it on Earth, LLNL built a massive laser system that spans the size of three football fields. The beams are fired into so-called fusion targets, which are tiny metal cylinders with a fuel pellet made of hydrogen isotopes. When temperatures soar hotter than the sun’s core, the pellet implodes and produces net energy.
Early on, Lawson was quick to identify the obstacles to converting physics that had taken 60 years to prove into a commercial power plant, Dunne said.
First of all, fusion targets are expensive. Each cylinder can cost between $100,000 and $200,000 and very few are manufactured each year. At a power plant, lasers need to be fired 10 times each second, meaning it could burn millions of dollars per second. Fusion targets must drop to $1 a piece, Dunne said.
Inertia also needs to build a cheaper, more efficient laser system. The one at LLNL uses older, massive technology that only fires a few times a day. Inertia is working on a smaller, faster version that uses semiconductor diode technology, which will have to be tested for performance — about a year-long process. Right now, a power plant with that kind of laser system might cost $100 billion to build because there are only boutique manufacturers, Dunne said.
“That’s never going to be commercial,” Dunne said. “This has been a catch-22 for about a decade. Each individual unit is very expensive, so nobody buys that many. So the companies that make them don’t invest much, either. The way we’re approaching this is basically throwing the biggest order ever at the market to build the prototype laser system for a power plant.”
Dunne said that buy-in-bulk strategy is adopted from the smart phone and semiconductor industries. Apple pioneered FaceID to unlock its devices, which uses laser diodes to shine infrared light to the shape of our faces. The company needed enough of that technology to make hundreds of millions of iPhones. It took several years to scale up production, but now those diodes are a cheap commodity.
That’s why Inertia has hired employees from Apple and Waymo who worked at the intersection of prototype technology and manufacturing lines. Waymo, the autonomous vehicle company owned by Alphabet, created “lidar” lasers that allow cars to generate 3-D maps in real time.
Still, scaling up Inertia’s fusion supply chain will be an expensive endeavor in itself. The company raised $425 million in a Series A round, and Dunne acknowledged it’ll cost billions of dollars more to boost the supply chain to then build a pilot project and eventual commercial power plant.
Inertia cinematically named its laser system “Thunderwall.” The company plans to build a 50-megawatt prototype to prove its performance and electrical efficiency at grid-scale. And then a one-gigawatt commercial plant would host 1,000 of those laser beams.
No need to search for new physics
Dunne said there’s a major factor setting Inertia apart from its competitors in the fusion industry, such as Helion Energy and Commonwealth Fusion Systems.
Those companies are developing new plasma physics that haven’t demonstrated net-energy gain yet, at least publicly. However, they have preemptively lined up the hyperscalers Microsoft and Google to buy electricity from power plants that could come online by 2028 and beyond. Google is also a research partner of TAE Technologies, a fusion company acquired by President Donald Trump’s social-media firm this year.
By contrast, Inertia was born out of physics already validated by the U.S. government at LLNL, Dunne said. Plus, Kritcher remains an employee of the lab while also working at Inertia, an arrangement allowed by the CHIPS and Science Act enacted in 2022. As part of the collaboration with LLNL, Inertia has access to nearly 200 patents developed there.
“There’s 30 to 40 different approaches to fusion out there. So how do you tell the difference between them?,” Dunne asked. “I think about it in terms of searching for new physics — which is what everyone else is doing — or knowing the physics and trying to figure out how to scale the technology.”
That said there are many challenges ahead for Inertia, and for the entire industry. Inertia has to test a bunch of semiconductor diode lasers to determine which one has the right performance; and it’ll take years to scale up manufacturing lines for the full Thunderwall system. Dunne predicted that Inertia won’t start construction on its pilot power plant until 2030 — meaning a utility-scale version is likely at least a decade away.
Editor’s note: This story was updated with a correction on June 25, 2026. An earlier version of this story called Inertia’s laster system “Thunderdome.” The laser system is called “Thunderwall,” while the fusion power plant it plans to build is called “Thunderdome.”
