Earlier this month, the UK government invited offers for making available over 100 hectares of land to set up the world’s first nuclear fusion power station that would supply electricity to the national grid. The UK Atomic Energy Authority (UKAEA) expects to start construction on the project, known as the Spherical Tokamak for Energy Production (STEP), around 2030, while the plant could begin operating in 2040.
Although STEP, which is estimated to cost a whopping $2.5 billion, is being projected as a key element in the UK’s plans to achieve net zero emissions by 2050, it is designed to supply only 100 MW of power. As a prototype fusion reactor that reproduces the way the sun makes energy by fusing hydrogen together to make helium, STEP’s connection to the electricity grid would help to understand the operation of a fusion power plant on a day to day basis. According a UKAEA senior official Ian Chapman, “STEP is a hugely ambitious programme – to be at the forefront, to be the first in the world to produce a prototype fusion power plant, and then export that round the world”.
The offers for the STEP host land site can be made until March 2021, and the UKAEA expects to take a final decision on the site by the end of 2022. The UKAEA already hosts a fusion reactor – the Joint European Torus (JET) – currently the world’s largest “tokamak” (derived from the Russian words for “toroidal magnetic confinement”) that was constructed in the 1980s and which is nearing the end of its working life.
Meanwhile, the machine assembly of the tokamak nuclear fusion reactor ITER (International Thermonuclear Experimental Reactor), or the world’s largest nuclear fusion project, began in July this year at Cadarache in France. This assembling work of the $25 billion multinational ITER project is expected to last 5 years.
The ITER machine is being assembled to replicate the fusion power of the sun, to enable generation of clean unlimited energy, and the first ultra-hot plasma is expected to be generated in late 2025. The world’s largest science project is intended to demonstrate that fusion power can be generated on a commercial scale.
ITER will be the first project to achieve a self-heating plasma and is expected to generate 10 times more heat than is put in. Fusion provides clean, reliable energy without carbon emissions, with minute amounts of fuel and no physical possibility of an accident with meltdown.The fuel for fusion is found in seawater and lithium, while it is abundant enough to supply the world for millions of years. A football-sized amount of this fuel is equivalent to around 10,000 tons of coal.
The plant at ITER will produce about 500 MW of thermal power. If operated continuously and connected to the electric grid, that would translate to around 200 MW of electric power, which is sufficient for the average needs of 200,000 homes. A commercial fusion plant will be designed with a slightly larger plasma chamber, for 10-15 times more electrical power. For instance, a 2,000 MW fusion power plant could supply electricity to two million homes.
