WISCONSIN — Realta Fusion illuminated a lightbulb on June 19, 2026, using electricity drawn directly from its WHAM demonstration fusion device. The company stated this marks the first public demonstration by a private company of generating electricity directly from a fusion reaction.

"We can take power from a plasma," said Kieran Furlong, co-founder and CEO of Realta Fusion. The company plans to use direct electricity conversion to heat the plasma within its reactor. "You're basically able to recirculate the electricity," Furlong said.

Furlong estimated the direct conversion process is approximately 90% efficient. He noted that steam turbines used in current fission reactors operate at roughly 33% efficiency. According to Furlong, this circularity could increase a commercial-scale power plant's total output by 20% to 30%.

The company constructed a prototype electricity converter and attached it to the end of its reactor. This prototype harvested enough alpha power to produce multiple amps of electricity at 100 volts. About 20% of the energy from deuterium-tritium fusion reactions comes from charged helium nuclei, known as alpha particles.

The WHAM device is designed to demonstrate the magnetic mirror approach to fusion power. "Harvesting electricity directly from the fusion reaction really helps with the economics of a reactor's design," Furlong said. Helion also intends to use direct energy conversion in its reactor but has not publicly demonstrated it.

In 2025, Realta Fusion secured $36 million in a funding round led by Future Ventures. The company is presently working to raise a new funding round.