Inertia Enterprises announced it has raised a $450 million in Series A financing to advance a commercial fusion energy program based on inertial confinement fusion physics demonstrated at the National Ignition Facility at Lawrence Livermore National Laboratory. The company, founded in 2024 and based in Livermore, California, said the round was led by Bessemer Venture Partners with participation from GV, Modern Capital, Threshold Ventures, and other investors.
The company said the milestone-based capital will support two primary development tracks: building what it described as the world’s most powerful laser system for its Thunderwall approach, and creating a production line to mass-manufacture fusion-fuel targets. Inertia said those efforts are designed to underpin a phased commercialization roadmap aimed at delivering grid-scale fusion electricity through a pilot plant and ultimately a gigawatt, utility-scale fusion power plant within the next decade.
Inertia is led by co-founder and CEO Jeff Lawson, with Dr. Annie Kritcher as a co-founder and chief scientist and Prof. Mike Dunne as a co-founder and chief technology officer. Kritcher has been a lead designer of fusion experiments at NIF since 2017 and has spent more than 20 years at LLNL, where she led the development of the “Hybrid-E” inertial confinement fusion integrated physics design, including hohlraum, capsule, and laser specifications, as well as the experimental design. The company said the design enabled the December 2022 experiment that achieved net target energy gain, producing more fusion energy than was delivered to the target, and that Kritcher is serving as Inertia’s chief scientist under an agreement that allows her to continue in her role at LLNL.
Dunne joins from Stanford University and SLAC National Accelerator Laboratory, where he previously served as director of the Linac Coherent Light Source research facility. Inertia said Dunne also led a five-year program at LLNL focused on an industry-validated power plant design based on the lab’s ignition approach and previously oversaw the development of high-power lasers as director of the UK’s Central Laser Facility.
Inertia said its fusion power plant design centers on Thunderwall, a laser beamline intended to deliver a 10 kJ beam 10 times per second with 10% wallplug efficiency using scalable semiconductor diode technology. The company said Thunderwall would be 50 times as powerful in average power as any prior laser of its type. Inertia said it plans to pair that laser performance with mass manufacturing of targets based on Kritcher’s design and a system to feed targets into chambers on sub-second timescales, with the goal of building a commercially viable, grid-scale fusion power plant.
KEY QUOTES:
“Inertia is building on decades of science and billions of dollars invested to reach the ignition milestone that proved the science. Our plan is clear: build on proven science to develop the technology and supply chain required to deliver the world’s highest average power laser, the first fusion target assembly plant, and the first gigawatt, utility-scale fusion power plant to the grid. Inertia is building the team, partnerships, and capabilities to make this real within the next decade.”
Jeff Lawson, the co-founder and CEO of Inertia and former founder and long-time CEO of Twilio
“In just three years, we’ve gone from the first experiment to ever produce more fusion energy than was delivered to the target, to repeating that result many times and pushing the target gain higher. We’re now focused on translating physics we know works into a pathway toward commercial-scale fusion energy, and the real benefits it can deliver for people and the planet.”
Dr. Annie Kritcher, Co-Founder And Chief Scientist, Inertia Enterprises
“For the first time, the fusion industry is seeing the alignment of three elements crucial to commercialization: proven physics, public sector partnerships, and private sector investment at the scale needed to deliver,” said Dunne. “It’s our job to capitalize on these elements to build fusion energy that works at grid scale.”
Prof. Mike Dunne, Co-Founder And Chief Technology Officer, Inertia Enterprises
“Inertia represents our first investment into the direct fusion market, because it is the first company that we’ve seen with a clear roadmap to commercial energy that’s compelled us to act,” said Byron Deeter, a partner at Bessemer Venture Partners. “With a combination of frontier physics expertise and proven company-building experience, Inertia is unique. We’re thrilled to partner with them as they work to deliver abundant, safe, and clean energy.”
Byron Deeter, Partner, Bessemer Venture Partners
