Helion funding round grows to $500M amid uncertainty over fusion startup's Microsoft  timeline

Fusion energy startup Helion Energy announced the addition of $35 million to its recent Series G funding round, bringing the total raised in the round to $500 million and lifting total funding to over $1.5 billion to date. The Everett, Washington-based company is targeting the commercialization of fusion energy, backed by notable crossover, pension, and sovereign wealth investors at a reported valuation of $15.5 billion. Helion is working under an ambitious commercial timeline driven by an agreement signed three years ago with Microsoft (MSFT.OQ) to supply electricity to a Central Washington data center by 2028. Construction is ongoing on its 50-megawatt fusion power plant, Orion, located in Malaga, Washington. Despite technical skepticism from plasma physicists and reports indicating full commercial capacity could be delayed to 2030, Helion is actively testing small-scale prototypes such as Tiny Merge to overcome core engineering challenges. The capital infusion reflects strong institutional appetite for zero-carbon baseload electricity needed to power next-generation artificial intelligence infrastructure, directly benefiting technology hyperscalers such as Microsoft seeking long-term clean power solutions.