Updated: Jan 9
The UK’s government has announced a new package of climate policies, including £220m for research into nuclear fusion reactors to provide clean energy “by 2040”.
Nuclear fusion is the process that powers stars like our sun. Unlike current nuclear power plants – which split atoms in a process called fission – nuclear fusion binds atomic nuclei together. This releases much more energy than fission and produces no high-level nuclear waste.
A fusion reactor would also produce zero carbon emissions and wouldn’t run the risk of a nuclear meltdown. Fusion could produce energy regardless of wind conditions or daylight hours, and wouldn’t require enriched uranium, which can be repurposed for nuclear weapons. As good as this all sounds, nuclear fusion is unlikely to play a major role in fighting climate change. To understand why, we need only look at the current state of fusion research.
Fusion: for the stars, for now
For decades, the performance of fusion devices has been improving – the capacity of scientists to confine hot hydrogen plasma has improved by a factor of 10,000. This plasma has to be over 100,000,000°C in order for the hydrogen nuclei to fuse and generate energy.
The next big step is ITER, a huge project involving 35 nations, under construction in the south of France. ITER’s purpose is to test our ability to confine plasma for long enough and at a high enough density and temperature. Its goal is to be the first fusion device to produce more energy from the plasma than is put into it. But ITER isn’t a power station, it’s an experiment. The plan is to build a demonstration fusion power plant – called “DEMO” – after ITER shows it’s possible for the plasma to generate a net gain in energy.