Nuclear Fusion, Millions Rain Down on Helion: Can It Really Bring Energy to the Grid in Two Years?

Helion, a startup specializing in the development of nuclear fusion and backed by Sam Altman, has announced the closing of a new funding round totaling $465 million. This operation brings the company's valuation to approximately $15.5 billion, confirming strong investor interest in the fusion energy sector.

The capital injection arrives at a crucial phase for the company, which is committed to realizing Orion, the first energy plant designed by the firm. Helion is trying to adhere to a particularly ambitious timeline, aiming to inject fusion energy into the power grid as early as 2028, in line with agreements signed with Microsoft.

The company had already obtained $425 million in early 2025. Adding up all the funds raised to date, the total capital amounts to about $1.5 billion. The new Series G round was led by Thrive Capital and included participation from numerous investors, such as Alta Park Capital, Anti Fund, BoxGroup, Lux Capital, Peak XV Partners, and Bill Ford. Several existing investors in the company, such as Capricorn Technology Impact Funds, Lightspeed Venture Partners, Mithril Capital, Good Ventures Foundation, SoftBank Vision Fund 2, and a university fund, also participated in this operation.

Helion and the Fusion Reaction Project

From a technological standpoint, Helion is following a different path compared to many other companies active in the nuclear fusion field. While some competitors use magnetic fields to confine plasma and others employ lasers to compress the fuel, the company aims to generate electricity directly through the reactor's magnetic system.

According to the project, the fusion reaction causes the plasma to expand, exerting a force on the magnetic fields. This energy could potentially be converted directly into electricity without going through steam turbines, potentially increasing the efficiency of the plant. Despite these prospects, some experts maintain a cautious attitude.

Among the reasons for the debate is the limited number of peer-reviewed scientific publications by the company. However, CEO David Kirtley has repeatedly asserted that it will be the practical results obtained by the reactors that will validate the approach taken. Helion is not the only entity attracting new investments. In recent months, other companies in the sector, such as Focused Energy, Thea Energy, Inertia Energy, and Type One Energy, have also raised significant funds.