Inertia Enterprises has raised $450 million to build one of the world’s most powerful lasers. This laser is intended to serve as the foundation for a grid-scale power plant, with the fusion startup planning to begin construction in 2030.
The company is building on technology developed at the Lawrence Livermore National Laboratory’s National Ignition Facility. The NIF is the site of the world’s only controlled fusion reactions that have reached scientific breakeven, where the reaction releases more energy than it took to initiate it.
This Series A funding round was led by Bessemer Venture Partners. Participation came from GV, Modern Capital, Threshold Ventures, and others. Inertia’s co-founders include Jeff Lawson, who co-founded Twilio and served as its CEO, Annie Kircher, who led the successful experiments at NIF, and Mike Dunne, a Stanford professor who helped Lawrence Livermore develop a power plant design based on NIF. Kircher has remained in her position at Lawrence Livermore.
While NIF’s breakeven experiments are a key milestone for fusion power, significant progress is still needed before a plant can deliver electricity to the grid. For Inertia, this means building a laser capable of delivering 10 kilojoules of energy ten times per second.
The startup’s reactor uses a form of fusion known as inertial confinement. In Inertia’s approach, lasers bombard a fuel target, compressing the fuel until atoms inside fuse and release energy. This technique is based on NIF’s designs, where laser light is converted into X-rays inside the target. Those X-rays ultimately heat and compress the fuel pellet.
Each of Inertia’s planned power plants will require 1,000 of its lasers bombarding 4.5mm targets. The company aims to mass-produce these targets for less than $1 each. In contrast, the NIF system uses 192 lasers to fire on meticulously crafted targets that take dozens of hours to manufacture. Inertia is betting that by using the same basic principles as NIF but applying a commercial mindset, it can dramatically reduce costs.
Inertia’s new funding is the latest in a series of announcements from fusion startups in recent months. Collectively, fusion startups have now attracted more than $10 billion in investments, with at least a dozen companies having raised over $100 million.
Last week, Avalanche said it had raised $29 million to advance its desktop-sized fusion reactor. Earlier this year, Type One Energy reported it had attracted $87 million in investment ahead of a $250 million Series B round it is currently raising. Last summer, Commonwealth Fusion Systems raised $863 million from dozens of investors, including Google, Nvidia, and Breakthrough Energy Ventures.
Two fusion companies have recently announced plans to go public via reverse mergers. In January, General Fusion said it would merge with acquisition company Spring Valley III in a deal valuing the combined company at $1 billion. General Fusion had previously struggled to raise money from private investors. Earlier last month, TAE Technologies announced it would merge with Trump Media & Technology Group in an all-stock transaction that would value the combined company at $6 billion.