Fusion energy company Helion announced that it has raised $465 million in a Series G funding round, with proceeds aimed at accelerating commercial deployment of fusion energy in the U.S. and expanding the company’s operations.
The new financing round values Helion, which aims to build the world’s first fusion power plant, at $15.5 billion, nearly triple the valuation from its Series F raise in early 2025.
Fusion, the process of combining two atoms to release energy, is seen as a potential source of abundant, zero-carbon power. Unlike fossil fuels, fusion does not emit carbon, and unlike nuclear fission, it does not generate highly radioactive waste. Large-scale fusion energy generation has remained elusive, however, given the need to create extremely high temperatures and pressure.
Founded in 2013 by CEO David Kirtley, John Slough, Chris Pihl, and George Votroubek, Washington-based Helion is developing fusion technology with the goal of building the world’s first commercial fusion power plant. The company signed an agreement with Microsoft in 2023 to supply the tech giant with fusion generated carbon-free energy by 2028 from its first power plant in Malaga Washington, Orion, which is currently under construction.
The new funding round follows several industry-first milestones achieved by Helion’s seventh-generation Polaris prototype fusion machine, including becoming the first privately funded fusion machine to operate with deuterium-tritium fuel and surpassing the company’s previous plasma temperature record, exceeding 150 million°C, earlier this year.
David Kirtley, CEO of Helion, said:
“Fusion is no longer a future idea, but a path to clean, reliable, affordable always-on electricity at scale. This funding accelerates our ability to deliver on that promise.”
The funding round was led by Thrive Capital, with participation from new investors including Alta Park Capital, Anti Fund, BoxGroup, Lux Capital, Peak XV Partners, and Ford Motor Company Executive Chairman Bill Ford, alongside existing investors Capricorn Technology Impact Funds, Lightspeed Venture Partners, Mithril Capital, Dustin Moskovitz through Good Ventures Foundation, SoftBank Vision Fund 2, and a university endowment fund.
Vince Hankes, partner at Thrive Capital, said:
“We believe Helion has the technical ambition, pace of execution, and commercial orientation to define a new category of energy. We are deeply inspired by David and the Helion team’s mission to bring clean, reliable fusion power to the world, and honored to support them for the long arc ahead.”
