Commonwealth Fusion Systems Raises $1 Billion, But It’s Really Just A Down Payment For Their ARC Machine

Fusion Energy

Pacific Fusion and Lawrence Livermore National Laboratory announced that Sirius, an impedance-matched Marx generator prototype designed and built at LLNL, has surpassed 3,000 shots under a Cooperative Research and Development Agreement. In the campaign, each pulse of the four-stage prototype delivered 60 gigawatts to a resistive load in a 100-nanosecond pulse at 95% energy efficiency, with the effort focused on component lifetime and reliability. The companies frame the result as evidence that technology developed at a national laboratory can be validated through repeated testing and scaled quickly by industry. Pacific Fusion says it has used the data to build a June prototype that reached roughly 440 GW of peak output power and about 1.1 MV in 80 nanoseconds, and it plans to break ground later this summer on its Demonstration System in Albuquerque, New Mexico. The Fusion Report weighs the milestone against the roughly 31.5 million shots a production pulser would need to run for a year, and the tritium and neutron challenges that remain.

Fusion Energy

This week Pacific Fusion and Lawrence Livermore National Laboratory reported that the Sirius pulsed power prototype has surpassed 3,000 shots, validating the impedance-matched Marx generator architecture that Pacific Fusion has already scaled into a system delivering the highest peak power ever from a single-step pulsed power driver. Inertia Enterprises opened its new Livermore headquarters, a 50,000 square foot facility housing the world’s first fusion fuel target factory. Oak Ridge National Laboratory, Cleveland Clinic, and IBM completed the first known quantum computations of fusion fuel materials, modeling nine configurations of the tritium breeding salt FLiBe. And General Fusion became the first publicly listed fusion company as GFUZ began trading on the Nasdaq with roughly $150 million in cash. Plus The Fusion Report’s mid-year 2026 funding status and Realta Fusion selects Madison, Wisconsin for its new headquarters and The Realta Forge R&D facility backed by up to $55 million in state and city incentives.

Fusion Energy

The Fusion Report’s mid-year 2026 funding status finds total lifetime private funding for commercial fusion at $11.52B as of June 30, 2026, up roughly $2.4B from June 2025. Four companies now top $1B in lifetime funding: Commonwealth Fusion Systems ($2.923B), Helion Energy ($1.502B), TAE ($1.321B), and Shine Fusion ($1.040B). Major rounds in the period include CFS at $863M, Helion at $465M, Inertia at $450M, and $240M each for Shine Fusion and Focused Energy. Nuclear fission and SMR startups raised roughly $2B in the same window, while AI captured 70% of global VC funding in Q2 2026 alone. In a July postscript, Proxima Fusion raised €411M ($468M US) in new funding and General Fusion went public on the NASDAQ, lifting industry lifetime funding to $12.18B.

Fusion Energy

Realta Fusion announced it will build its corporate headquarters and fusion R&D facility, “The Realta Forge,” at OM Station, the former Oscar Mayer plant in Madison, Wisconsin. The state and city committed up to $55 million in incentives: an estimated $37.5 million in state sales and use tax exemptions, up to $15 million in WEDC enterprise zone tax credits, and $2.8 million in city tax increment financing. Realta expects to create over 600 jobs and to break ground before the end of the year on the facility where it will build Hammir, its prototype magnetic mirror fusion machine. The deal follows Wisconsin Act 165, the first standalone state law in American history to exempt fusion energy capital expenditures from state sales tax. The Fusion Report looks at why the hometown choice makes sense and what it signals about Realta’s next funding round.

Energy Industry

With wait times for large gas turbines now exceeding five years, Arbor Energy, founded by former SpaceX engineers, has raised a $55M Series A to advance its 25 MW modular Halcyon turbines, which combine rocket turbopump technology, a supercritical CO2 power cycle, and 3D-printed core components. The company has also secured an order from GridMarket for up to 200 units, reportedly worth billions of dollars.

Fusion Energy

Proxima Fusion raised 411 million euros ($468 million) led by XTX Ventures and East X Ventures with Google and RWE as strategic investors, a 2.4 billion euro valuation that makes it Europe’s best funded fusion company. Spring Valley and General Fusion shareholders approved the merger that lists General Fusion on Nasdaq as GFUZ, the first publicly traded pure play fusion company. UKAEA and Eni launched RH3OVA, a joint venture selling consultancy and operational services to the global fusion industry. And China completed final tests on the world’s largest superconducting fusion magnet, a 582 ton coil built entirely with domestic supply chains. Plus Helical Fusion signs a construction MoU for Helix KANATA, and Cosylab CEO Mark Plesko on why control systems are the missing backbone of commercial fusion.

Fusion Supply Chain

The Fusion Report interviews Mark Pleško, CEO of Cosylab, a 250-person Slovenian company that has built control systems for ITER, UKAEA, and major research labs for over two decades. Pleško explains why fusion startups tend to treat controls as a problem to solve later, what that technical debt costs them, and how the Fusionics initiative co-founded with UKAEA aims to give the industry a standard control framework.

Fusion Energy

Helical Fusion has added a long-established Japanese general contractor to its Helix Program as an Official Partner and signed a memorandum of understanding to collaborate toward the construction of Helix KANATA, the company’s fusion pilot plant targeted for the 2030s. The two firms will examine construction requirements and project execution approaches for future fusion power facilities. The contractor joins the earlier Official Partners announced in April 2026 in building out the industrial foundation for commercial fusion in Japan.