Compact Fusion Reactor MiniFusion Prototype Lights First Bulb in UK: 10MW Container-Sized Fusion Power

Compact Fusion Reactor MiniFusion Prototype Lights First Bulb in UK

On March 15, 2029, Tokamak Energy in Oxfordshire, UK, announced that its MiniFusion compact fusion reactor prototype ST80-HTS achieved sustained net energy output for the first time. During 2 hours of continuous operation, the reactor produced approximately 1.5 times the input energy, with total output of about 200kWh. CEO Chris Kelsall symbolically demonstrated the milestone by lighting a light bulb with power from the reactor.

MiniFusion's design philosophy differs radically from traditional large fusion projects. ITER and other mainstream fusion projects use large tokamak devices costing tens of billions of dollars, with volumes comparable to small buildings. MiniFusion uses a compact spherical tokamak design, with the plasma confinement section fitting inside a single shipping container, targeting a cost of approximately $50 million.

The key technical breakthrough lies in the use of high-temperature superconducting (HTS) magnets. MiniFusion's rare-earth barium copper oxide (REBCO) superconducting tape generates 20-tesla magnetic fields at 20K temperatures — about 5 times stronger than traditional low-temperature superconducting magnets. Stronger magnetic fields mean plasma can be confined in smaller devices.

Tokamak Energy Chief Scientist Mikhail Gryaznevich said: "Fusion has a classic problem — bigger is better. Our HTS magnets break that rule. ST80-HTS's plasma volume is one-hundredth of ITER's, but plasma temperatures have reached 100 million degrees Celsius, matching ITER's design specifications."

However, the 200kWh output still has a vast gap to MiniFusion's design target of 10MW. The company says it will complete ST80-HTS full-power testing in 2030 and deliver the first commercial 10MW unit before 2032. Target customers are remote areas, military bases, and data centers requiring independent power sources.

Imperial College London fusion research center director Federico Felici expressed caution: "200kWh net energy output is an important scientific milestone, but there are still engineering reliability, tritium self-sufficiency, material durability, and other challenges between prototype and commercial units. Fusion's history is filled with unfulfilled promises."