If not for the first of these, fusion would seem to be an attractive process for meeting energy needs. The fuel is abundant (based on the water available on the earth and its deuterium content the estimate is 5 x 1015 tonnes of H-2) and the "waste" generated is certainly less than for comparable fission processes.
We are able to produce fusion reactions but not in a form that is of much use: hydrogen bombs. In these thermonuclear weapons the activation energy for the fusion reaction is supplied by a fission reaction! Clearly such technology is not going to run anyone's toaster any time soon.
There are competing experimental fusion reactor
designs 
but so far results have been disappointing. The extremely
high energy input required to overcome the electrostatic
repulsive forces of the nuclei, containment problems and
difficulties making the reaction self-sustaining have proven to
be formidable challenges. Funding for research is, as always,
another serious problem.
