Inertia Enterprises raises $450 million for fusion power plant

Inertia Enterprises has raised $450 million in Series A funding to build a powerful laser. The startup hopes the laser will serve as the foundation of a grid-scale power plant, which it intends to start construction on in 2030. The funding round was led by Bessemer Venture Partners, with participation from GV, Modern Capital, Threshold Ventures, and others. Inertia’s co-founders include Jeff Lawson, the co-founder of Twilio; Annie Kritcher, a researcher at Lawrence Livermore National Laboratory who led successful experiments there; and Mike Dunne, a Stanford professor who helped the laboratory develop a power plant design. Kritcher has remained in her position at Lawrence Livermore.

The startup is building on technology developed at the Lawrence Livermore National Laboratory’s National Ignition Facility (NIF). The NIF is the site of the world’s only controlled fusion reactions that have reached scientific breakeven, which is a fusion reaction releasing more energy than it took to start. However, considerable progress needs to be made before a fusion power plant can deliver electricity to the grid. For Inertia, that means building a laser capable of delivering 10 kilojoules 10 times per second.

Inertia’s reactor relies on inertial confinement, which is a form of fusion where lasers compress fuel. In this process, lasers bombard a fuel target, compressing the fuel until atoms inside fuse and release energy. While the NIF’s experimental system uses 192 lasers to fire on painstakingly crafted targets, Inertia’s commercial design will require 1,000 of its lasers bombarding 4.5 mm targets. The startup aims to mass produce these targets for less than $1 each. Inertia is betting that by using the same basic principles as NIF and applying a more commercial mindset, it can bring the costs down dramatically.

This funding is part of a broader surge of capital into the fusion sector, which has attracted more than $10 billion in total investments, with at least a dozen companies raising more than $100 million. Recent activity in the sector includes:

• Avalanche: Announced last week that it had raised $29 million to advance its desktop-sized fusion reactor.
• Type One Energy: Attracted $87 million in investment earlier this year, ahead of a $250 million Series B round it is currently raising.
• Commonwealth Fusion Systems: Raised $863 million last summer.
• General Fusion: Announced a merger in January with Spring Valley III, valuing the combined company at $1 billion.
• TAE Technologies: Announced a merger earlier last month with Trump Media & Technology Group, valuing the combined company at $6 billion.

Why it matters

Inertia’s $450 million raise highlights the massive capital flowing into fusion, as startups attempt to transition from scientific breakeven experiments to commercial grid-scale power plants.