Thea Energy wins $20M ARPA-E grant to scale fusion magnet manufacturing

Thea Energy received a $20 million award from ARPA-E, the Department of Energy agency, to help manufacture modular high-temperature superconducting magnets. The award targets a core cost challenge for hard-tech startups: scaling specialized hardware. For Thea, the immediate focus is magnet production for fusion reactors.

High-temperature superconducting magnets are costly but important components in magnetic confinement reactors. In those systems, powerful magnetic fields contain and compress plasma, helping heat particles until the fuel can fuse and release large amounts of energy. That makes magnet design and manufacturing a major lever for companies trying to make commercial fusion practical.

Thea’s reactor is based on a stellarator, a design that uses a twisted, squeezed inner-tube-like shape to confine plasma more effectively. Instead of relying on many custom magnet shapes, Thea uses fewer variants: 12 large magnets made from four templates, plus more than 300 identical smaller magnets to fine tune the plasma. The small magnets are software-controlled and arranged around the reactor’s periphery like pixels, an approach Thea says could allow more forgiving construction tolerances and lower costs.

Thea is among the top-funded fusion power startups cited by TechCrunch, after raising $100 million in May and a $20 million Series A in 2024. The company, like many peers in fusion, has plans to build a commercial-scale fusion power plant in the mid-2040s. The key takeaway: this grant is not a commercial deployment milestone, but it supports the manufacturing step behind Thea’s magnet-heavy reactor strategy.