Tokamak Energy Joins Tokyo’s GX Program

In a notable cross-border fusion development, Tokamak Energy has been selected for Tokyo Metropolitan Government’s Green Transformation (GX) Foreign Company Entry Support Program, an initiative targeting foreign innovators in clean energy technologies. Tokamak Energy, which is developing compact spherical tokamaks with high-temperature superconducting (HTS) magnets, was one of seven companies chosen from 59 entrants across 20 countries.

This recognition comes on the heels of Tokamak Energy’s recent expansion into Japan. The company incorporated a subsidiary in Tokyo earlier this year to cement its presence in the Japanese market​.

From a strategic perspective, Tokamak Energy’s move into Tokyo is well-timed. Japan has been steadily increasing its support for fusion as part of a national push for energy diversification. The Fusion Energy Innovation Strategy adopted in 2023 calls for building a domestic fusion pilot plant by the mid-2030s, with major government backing for public-private collaborations. 

Geopolitically, Japan’s heavy reliance on energy imports (and a national mandate to boost energy security) creates a strong appetite for potentially breakthrough energy solutions. The island nation is the world’s fifth-highest consumer of oil and the largest importer of liquified natural gas.

Still, Tokamak Energy is entering a crowded field. Japan already hosts homegrown startups like Kyoto Fusioneering, as well as academic-led efforts at institutions like the University of Tokyo. These groups are pursuing a mix of technologies, from inertial fusion to magnetic confinement approaches, and have closer historical ties to Japan’s domestic research base. Tokamak Energy will need to carve out a clear niche if it hopes to become more than just a guest participant.

The FAST Project

The centerpiece of Tokamak Energy’s involvement in Japan is the FAST project (Fusion by Advanced Superconducting Tokamak), an ambitious initiative officially launched in late 2024. 

FAST represents Japan’s first privately led fusion pilot plant development program, with the goal of demonstrating sustained fusion-based electricity generation in the 2030s.

What makes FAST particularly noteworthy is its collaborative model. The project brings together a broad group of partners from industry and academia in Japan and abroad, including Tokamak Energy, Kyoto Fusioneering (which spearheaded the project), the University of Tokyo, and international players like General Atomics. 

The team is designing a compact, low-aspect-ratio tokamak (essentially a spherical tokamak) equipped with HTS magnet coils, Tokamak Energy’s specialty.

Targeted performance for FAST is in the range of 50–100 MW of fusion output with long pulse durations on the order of hundreds of seconds per pulse. If successful, it would mark a significant leap beyond the short-pulse, low-power experiments of the past.

However, the FAST project’s aggressive goals also highlight the substantial engineering challenges ahead. Moving from plasma physics demonstrations to a functioning power plant requires solutions to a host of complex problems:

• Neutron-resistant materials that can survive the intense environment inside a fusion core
  

• Heat extraction systems capable of handling gigawatt-scale thermal loads
  

• Tritium breeding and recycling to sustain the fusion fuel cycle
  

• Precise plasma control under reactor-grade conditions

Compact spherical tokamaks, while promising in terms of efficiency, intensify these challenges because of their tighter geometries and concentrated heat loads. In addition, while HTS magnets promise higher field strength and compactness, their durability under intense neutron bombardment remains unproven at the scales required for continuous power generation.

A Calculated Bet

The Tokyo Metropolitan Government’s GX program is a calculated bet: that opening the city to foreign deep-tech players will accelerate local innovation capacity in fields like fusion. Tokamak Energy’s award signals that Japanese policymakers view compact, HTS-enabled fusion as a viable candidate — or at least one worth nurturing alongside domestic efforts.