Helion's unorthodox approach to fusion power and relative secrecy has earned it plenty of fans — and critics. But don’t count its investors among the naysayers. © 2024 TechCrunch. All rights reserved.

A nuclear fusion startup backed by OpenAI founder Sam Altman has raised nearly half a billion dollars to build what it hopes to be the world’s first power plant using the next-generation energy source.

Helion, a fusion energy company, today announced a $425 million Series F investment round that will be used to scale commercialization efforts for the company’s groundbreaking fusion technology. The oversubscribed and upsized round had participation from new investors,

Building a working nuclear fusion reactor has proven to be a daunting challenge even for multiple wealthy nations, as we've seen with the much-delayed ITER project. However, a private start-up called Helion thinks it can build one and start supplying energy by 2028 by taking a different approach than other reactors.

According to TechCrunch, Helion will use its $425 million funding round to upgrade its manufacturing capabilities. The company currently relies on external suppliers to provide it with capacitors, a type of energy storage device. Helion hopes that moving capacitor manufacturing in-house will enable it to significantly speed up production.

Fusion startup Helion locked up a $425 million Series F — valuing the company at $5.4 billion — as the company looks to satiate Big Tech’s appetite for energy sources as power needs increase.

Back in 2023, Microsoft signed a 50MW power purchase agreement (PPA) with Helion for 2028 - a short time in fusion development timescales. OpenAI, led by Helion investor Sam Altman, is also thought to be looking to buy " vast quantities " of fusion power.