Thea Energy received a $20 million federal grant to build magnets for nuclear fusion reactors

For high-tech startups, manufacturing is an expensive endeavor. Now, Thea Energy has support from a Department of Energy grant.

The fusion energy startup told TechCrunch on Monday that it has received a $20 million award from ARPA-E to help manufacture its high-temperature superconducting (HTS) magnets.

HTS magnets are expensive but important components of any magnetic detention reactor, and are one of the two main ways startups are trying to harness fusion energy for commercial purposes. In magnetic confinement reactors, strong magnetic fields contain and compress the plasma, helping to heat the particles so the fuel can fuse and release large amounts of energy.

Theia’s reactor is based on a design known as a star. Stars look like inner tubes that have been coiled and compressed in ways that help them confine plasma more effectively. Most stars use magnets designed to mimic those twists and turns, which makes them expensive to manufacture.

To reduce manufacturing costs, Thea uses fewer variables. The 12 large magnets that do the heavy lifting are made from four different molds, and the more than 300 smaller magnets used to set the plasma are all identical. They are arranged around the perimeter of the reactor, similar to how pixels are distributed across a computer screen.

The small magnets are controlled by software, and the arrangement should allow for more forgiving construction tolerances, which could cut costs, Thea says.

Thea is among the largest-funded fusion energy startups, having raised $100 million in May on top of a $20 million Series A it raised in 2024. Like many of its peers, Thea plans to build a commercial-scale fusion power plant in the mid-2040s.