Realta Fusion, a nuclear fusion startup headquartered in Wisconsin, said it succeeded in directly recovering electricity from a fusion reaction to light bulbs.

On June 30 local time, IT outlet TechCrunch reported that Realta Fusion succeeded on June 19 in turning on a light bulb using electricity generated at its WHAM fusion demonstration device. The company said it was the first private company to publicly demonstrate a method of directly recovering electricity from a fusion reaction.

The key to the achievement is that the approach differs from existing methods of fusion power generation. In general, fusion power generation is being actively considered as a method in which heat from the reaction boils water to create steam, which then drives turbines to produce electricity. Realta Fusion, by contrast, applied technology that extracts electricity directly from the fusion reaction itself.

Kieran Furlong (키어런 펄롱), Realta Fusion co-founder and chief executive officer, said, "You can pull power directly from fusion plasma." He said the demonstration showed that such a technology is possible in practice.

The company plans to use deuterium and tritium as fuel in commercial reactors. In this fusion reaction, about 20 percent of the total energy is released in the form of charged helium nuclei, or alpha particles. Realta Fusion said it connected a self-developed electric conversion device to the end of the reactor to convert the energy of these alpha particles directly into electricity. It said it obtained current of several amperes at about 100 volts, and succeeded in lighting several bulbs simultaneously.

The company expects the technology could significantly reduce internal power consumption at power plants. Fusion power plants must consume substantial amounts of power to maintain and heat plasma. Realta Fusion estimated the direct electric conversion efficiency could reach about 90 percent. That is much higher than the roughly 33 percent power generation efficiency of steam turbines used at current nuclear power plants.

Furlong said that in commercial power plants, directly recovered electricity could supply a substantial portion of the energy needed for plasma heating. "You can effectively recirculate the electricity you produce," he said. "That structure can also increase the overall output of commercial fusion power plants by 20 to 30 percent," he added. He said it had a similar effect to spinning a flywheel of electricity.

The fusion industry has hit a technical turning point in recent years. After the U.S. National Ignition Facility succeeded in 2022 in obtaining more fusion energy than the energy it投入, industry attention shifted from whether fusion itself can succeed to securing commercial economic viability. In particular, how much electricity can be recovered and reused to operate reactors has emerged as a key competitive factor.

Realta Fusion is not the only company developing this technology. Helion, a fusion startup backed by OpenAI CEO Sam Altman, is also promoting direct electric conversion as a core technology. There has not yet been a public demonstration of it.

Investment is continuing. Realta Fusion said it raised $36 million in a Series A round led by Future Ventures last year, and is currently in the process of securing new investment.

The industry is assessing the demonstration as an example of a new approach that could improve the economic viability of fusion power generation, and expects that whether direct electricity recovery technology can be commercialised will be an important turning point in the competition for next-generation fusion power.