UK-based Tokamak Energy has unveiled plans for a prototype device that it says will produce close to the levels required for commercial fusion energy to be produced early in the next decade.
Based on a spherical tokamak shape – like a cored apple – the ST80-HTS machine will be able to achieve a higher and sustained value of fusion ‘triple product’ than any previous fusion device, it says.
Triple product is the fusion industry measure of plasma density (keeping the plasma tightly controlled so a sufficient number of fusion collisions occur), temperature (enough to make the particles move fast enough to fuse with each other but not too much to use more energy than is produced) and confinement (keep the charged particles within the plasma for long enough to sustain fusion reactions).
Privately owned Tokamak said its smaller ST40 spherical torus earlier this year achieved a triple product result at the commercial threshold plasma temperature of 100mln degrees Celsius, with the volume of plasma less than one cubic metre.
This level of triple product was the highest ever achieved by a private fusion energy company and a world-record temperature in a compact spherical tokamak.
Tokamak Energy, which is based in Oxfordshire, the heart of the UK if not the world’s fusion energy industry, said the ST80-HTS should be built by 2026 and inform the design of its planned fusion pilot plant that it hopes will demonstrate the capability to deliver up to 200 MW of net electricity into the grid in the early 2030s.
That would be a lot earlier than the new government-backed plan launched earlier this month for a similar spherical tokamak to be built by the UK Atomic Energy Authority, which aims to be built by 2040.
One aim of the ST80-HTS prototype is to produce a long pulse of around 15 minutes controlled plasma, which compares to a second or less with existing devices being developed.
“ST80-HTS will target the significantly longer pulse durations that are needed for sustained high power output in commercially competitive fusion power plants,” the company said.
Chief executive Chris Kelsall, a former banker at Deutsche Bank, ABN Amro and HSBC, as well as a commercial director at AFC Energy, said: “At a time of heightened global concern with energy shortages and escalating prices, there is an acute need for new, clean, dispatchable technologies to reduce carbon emissions, provide grid flexibility and security of power supply.”
He said the company’s goal of demonstrating the engineering solutions needed to make commercial fusion energy a reality “would provide humanity with access to clean, sustainable, on demand and low-cost energy, wherever and whenever it is needed”.