With the latest round of funding, Helion has raised over $1 billion in capital since it was founded in 2013. The company claims that it will build the world's first nuclear fusion power plant by 2028 and has already secured a purchase agreement from Microsoft which is a major investor in Mr Altman's OpenAI.

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.

Helion’s nuclear fusion promises have garnered the attention of Silicon Valley—and raised concerns amongst scientists wary of its aggressive timeline.

Seattle-area company Helion Energy gets $425 million from investors including Sam Altman and Softbank to pursue clean energy's "Holy Grail."

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. US-based Helion Energy recently unveiled its latest prototype in Everett, Washington, before announcing a $425 million funding round this week.

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.

Open AI CEO Sam Altman-backed Startup is investing in world's first nuclear fusion based power plant to solve the energy crisis in United States.