Construction on the ITER fusion reactor, which is a joint project by 35 nations (the United States, Russia, China, India, Japan, South Korea, Switzerland, and the 28 European Union countries) has begun, moving the revolutionary technology from a concept to physical reality.
The reactor, which is being built in southern France, is intended to serve as a blueprint for commercial fusion reactors.
Although the construction of a fusion reactor is extremely expensive, fusion, in theory, has the potential to provide nearly unlimited energy, as it only requires tritium and deuterium (water isotopes) as energy and produces helium as a waste product. The process of fusion is the same process which is happening inside the sun.
The biggest challenges are maintaining a continuous fusion reaction and containing the extreme temperature plasma inside the reactor. The latter is accomplished by gigantic magnets all around the reactor.
ITER brings the dream of unlimited energy one step closer to reality. The construction is expected to take about four to five years.