Helion, a US-based fusion energy firm, has commenced construction on its inaugural fusion power plant, Orion, in Chelan County, Washington.
According to Helion, this development is a significant milestone towards delivering fusion electricity to the grid. The site was strategically chosen for its access to existing transmission infrastructure and history of energy innovation.
In 2023, Helion signed a power purchase agreement (PPA) to supply energy from Orion to Microsoft by 2028, with Constellation Energy acting as the power marketer.
Microsoft chief sustainability officer and energy, connectivity, and sustainability corporate vice president Melanie Nakagawa said: “Fusion represents an inspiring frontier in the world’s pursuit of clean and abundant power.
“While the path to commercial fusion is still unfolding, we’re proud to support Helion’s pioneering work here in Washington state as part of our broader commitment to investing in sustainable energy.”
With construction now initiated, Helion said that it is on schedule to meet this commitment. This project is said to mark a pivotal advancement in the transition to sustainable energy, aiding Microsoft’s target of becoming carbon negative by 2030 and contributing to global clean energy efforts.
Helion co-founder and CEO David Kirtley said: “Today is an important day – not just for Helion, but for the entire fusion industry – as we unleash a new era of energy independence and industrial renewal.
“Since we founded the company, we have been completely focused on preparing fusion technology for commercialisation and getting electrons on the grid. Starting site work brings us one step closer to that vision.”
Helion has begun building on land leased from the Chelan County Public Utilities District (PUD) following a Mitigated Determination of Non-Significance (MDNS) under Washington’s State Environmental Policy Act (SEPA).
Previously, Helion engaged with varied stakeholders, including government bodies and Tribal Nations, in anticipation of siting and permitting decisions. The company said that it continues to progress through the necessary permitting steps to establish and operate the commercial fusion plant.
As a company focused on generating zero-carbon electricity through fusion, Helion aims to construct the world’s first fusion power plant for limitless clean electricity. Its iterative testing strategy is said to have propelled steady advancements toward a commercial fusion machine.
The 7th-generation prototype, Polaris, is set to demonstrate initial electricity production from fusion. Previously, Helion’s Trenta prototype achieved a fuel temperature of 100 million degrees Celsius, deemed essential for operating a commercial fusion plant.
In January 2025, Helion announced a $425m Series F funding round to accelerate commercialisation of its fusion technology. New investors such as Lightspeed Venture Partners and SoftBank Vision Fund 2 joined existing supporters including Sam Altman and Mithril Capital.
This round increased total investment in Helion to over $1bn, valuing the company at $5.4bn post-money.
