Inertia Enterprises secures $450M to mass-produce high-repetition fusion lasers

A major Series A of $450 million is backing a startup that aims to turn laboratory laser-fusion demonstrations into an industrialized electricity source by replacing handfuls of enormous research lasers with thousands of compact, rapidly fired beamlines. The company’s engineering plan centers on single-digit–kilojoule pulses delivered many times per second and an architecture that aggregates roughly 1,000 beamlines per plant, each striking small, inexpensive disposable fuel capsules to enable continuous operation rather than episodic experiments. Investors are buying into an industrialization thesis: that mass-produced targets, ruggedized optics and gain media, and factory-style assembly can move costs down enough to make laser-driven inertial confinement fusion commercially viable. The Series A funds are intended to build a world-scale laser demonstrator and support the industrial engineering, supply-chain scaling, and prototype economics work needed to pursue a 2030 construction milestone — a timeline many consider aggressive given the need to demonstrate reliable, synchronized millions of firings. The round also sits within a broader funding wave that includes smaller, complementary bets: recent financings for compact-fusion developers and investments in shared test infrastructure signal that investors and states are funding a variety of technical approaches. For example, a separate startup raised a $29 million round to accelerate compact devices and contribute equipment and testing capacity to a planned FusionWERX campus in Richland, Washington — a facility with state matching funds expected to open in 2027 that will host private companies, national labs and universities. Those parallel investments matter: shared test sites, specialized gear such as superconducting magnets, and targeted public support can accelerate component supply chains, certification paths, and radioactive-material handling capacity that benefit multiple fusion architectures. Yet the differences in approach are meaningful. Inertia’s strategy targets grid-scale throughput and commoditized consumables, while other firms focus on portable, high-power-density machines for defense, space, or niche off-grid markets — each path carries distinct engineering and regulatory challenges. Success for Inertia will hinge on near-term milestones: demonstrating sustained high-repetition firing, scaling target manufacturing to rates and costs consistent with continuous operation, and producing credible prototype plant economics. Even with abundant capital and a favorable investor environment, execution risk remains high; missed technical or manufacturing milestones would materially affect timelines, valuation and follow-on funding. Regulators and grid operators will require evidence of safety, durability and predictable output before permitting large-scale integration. Overall, the financing materially increases Inertia’s runway to de-risk engineering and supply-chain questions, and the concurrent investments across the industry — including shared facilities and compact-device development — create a richer ecosystem for component suppliers and testing, even as they raise expectations for demonstrable progress in the coming years.