Helion Energy hopes to use nuclear fusion to generate “net electricity” by 2024.

Helion Energy, which is building the world’s first fusion power plant that would enable a future with unlimited clean electricity, announced a $500 million Series E round led by Sam Altman. Existing investors, including Dustin Moskovitz, Mithril Capital and Capricorn Investment Group, also participated in the funding. Altman, who has been an early supporter of Helion and chairman since 2015, invested $375 million and will now play an expanded role as executive chairman. (CNBC)

Helio will use the money to complete construction of Polaris, Helion’s seventh generation fusion generator, expected to be the world’s first fusion device to generate electricity on a net basis by 2024, and a forerunner of future fusion plants.

“Our 6th prototype demonstrated that we can reach this pivotal milestone,” said Dr. David Kirtley, Founder and CEO of Helion Energy. “In just a few years we will show that the world can count on fusion to be the zero-carbon energy source that we desperately need.”

“This funding ensures that Helion will be the first organization to generate electricity from fusion,” he added.

“I’m delighted to be investing more in Helion, which is by far the most promising approach to fusion I’ve ever seen,” said Sam Altman, the CEO of OpenAI and executive chairman of Helion. “With a tiny fraction of the money spent on other fusion efforts, and the culture of a startup, this team has a clear path to net electricity. If Helion is successful, we can avert climate disaster and provide a much better quality of life for people.”

“This is the biggest investment I’ve ever made,” Altman told CNBC of his $375 million investment in the fusion startup.

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Image: As Deuterium is ionized into a fusion plasma, it emits a fuchsia glow (Helion Energy)