In the race to find reliable sources of renewable energy, a different type of nuclear power is being devised as a promising long-term solution.
For decades nuclear power has been generated using a process called fission. This is when unstable atoms such as uranium are torn apart, in a burst of energy and long-lived radiation.
Nuclear fission accounts for about 10 percent of the world's electricity, but carries the stigma of dire devastation – like the 1986 Chernobyl disaster, or the 2011 Fukushima disaster.
Nuclear fusion, by comparison, forces smaller atoms together. This results in a burst of energy, some helium by-products, and only a small amount of short-lived radiation.
Earlier this year, the JET reactor in Oxfordshire, England, achieved a major fusion breakthrough.
This generates about 60 megajoules of energy in a five-second burst - which is enough power to boil a jug 60 times.
