Another nuclear technology under development is nuclear fusion , which duplicates the energy production of the Sun and other stars. In nuclear fusion, hydrogen atoms are fused together under great temperatures and pressures to produce valuable helium and energy. That is, while nuclear fission involves the breakdown of heavy elements into lighter elements and energy, nuclear fusion involves the formation of heavier elements and energy from hydrogen. Currently, the technology is not available to produce a stable high pressure, high temperature fusion system. However, nuclear fusion reactors may be developed and commercialized in the next 30 years.
Nuclear fusion has the advantage of producing very little radioactive waste or other pollution.
Solar Energy Radiation from the Sun may be converted to electricity. Unfortunately, photovoltaic or solar cells are expensive and don't work at night. In addition, large areas would have to be covered with expensive solar cells to furnish enough electricity for even small cities. Furthermore, many people would object to having large tracts of land covered with solar cells. Under current economic and technological conditions, solar cells and solar heating technologies will only supplement, and not replace, other energy sources.