In securing long-term energy supplies for the world, nuclear fusion is an option that goes beyond the timeframe set out in Germany’s Energy Strategy.
Nuclear fusion is how energy is generated in the sun. Two light hydrogen isotopes, deuterium and tritium, fuse together and release energy. Helium is produced as a by-product. If this technology can be made to work in practice, it would bring huge advantages: the fuel would be available in almost unlimited quantities, the process is virtually climate neutral and it produces radioactive waste in smaller quantities and with shorter half-lives than conventional nuclear power plants.
Fusion research is not covered by the German government's Energy Strategy because the research work involved will stretch beyond 2050. Responsible research promotion thus calls for the monitoring of long-term social, industrial and technological developments.
This is the backdrop against which fusion research is promoted. If the scientific and technological challenges are overcome, it could supply a key, base-load contribution to the energy supply system of the future. For this reason, Germany is working with EU partners to build the International Thermonuclear Experimental Reactor (ITER), which aims to demonstrate the feasibility of generating energy from fusion processes for the first time using a 'burning' (self-sustaining) plasma in the 500 MW range. Two approaches are used to contain the plasma in a magnetic field: the tokamak and the stellarator. ITER uses a tokamak. Mainly to test the suitability of the stellarator technology at production scale, the world's largest and most advanced stellarator experiment, Wendelstein 7X, is being built in Greifswald. Their different magnetic containment approach means that stellarators, unlike tokamaks, are inherently capable of steady-state operation. However, they are not yet as thoroughly researched.