Nuclear fusion reactions that occur in our Sun produce huge amounts of energy. Is there any way to harness nuclear fusion reactions here on earth to produce electricity? No commercial nuclear fusion power plants currently exist, but some researchers hope that technologies can be invented to bring fusion power into production in an environmentally friendly way. Many governments have the same hope and have invested billions of dollars in pursuit of this dream. The centre of our Sun is very hot-about 15 million degrees celsious. For many decades, researchers have looked for a practical way to recreate the conditions at the centre of our Sun. They have produced extremely hot temperaturs during nuclear explosions, but this is not a practical way of producing electricity. An added challenge is that no container made of matter can contain gases that are as hot as the centre of our Sun. Any type of container would melt long before reaching those temperatures. However, there is another way to contain hot gases- with a strong magnetic field. How can you use a magnetic field to hold gases? hot gases lose electrons, turning all the atoms into ions. An ionized gas is called plasma. In a fusion power reation, a magnetic filed traps hydrogen plasma. One reactor design uses an electromagnet posiitoned in the shape of a doughnut. The hot plasma stays inside the doughnut and away from the magnets used to generate the magnetic field. Currently, a number of existing experimental facilities are suing this technology. Given thse tremendous challenges as well as huge development costs, why even bother to try to build a fusion power facility? If it could be made to work, fusion power is expected to have a number of advantages. The materials needed for fusion-isotopes of hydrogen-are as plentiful as the oceans themselves. Also, the products of nuclear fusion are expected to be stable isotopes, meaning that there might be no radioactive wastes to worry about. Finally a small amount of fusion produces a tremendous amount of enery.