Torulf wrote: Desalination with fission for [making] the desert green. The Nuplex concept [became too] expensive but with focus fusion it may be [brought] to life again.
Nuplex uses waste heat to boil salt water, and the vapor is condensed into fresh water. Focus Fusion creates electricity almost directly. Electricity is notoriously inefficient for heating. Perhaps a better method would be to pass electricity through the salt water and dissociate it into hydrogen and oxygen (electrolysis). The hydrogen could be used for vehicle fuel, or recombined with the oxygen to make fresh water. The heat from that reaction could boil additional salt water to fresh.
In addition, the hydrogen and oxygen can be created in the form of Brown’s Gas, which is reported to have some rather amazing properties.
http://www.brownsgas.com/brownsgashome.html