Thomas Malloy wrote.
>
> Perhaps we could regrow the Sahara Forest.
>
What do you mean, we, Pail Face? :-)
Simpler to use the kilowatt per square meter solar insolation
to evaporate sea water using passive floating heat pipe "stills"
where the heat of condensation is dumped into the sea.
Then pump the distilled water to the desert.
The heat pipe still is just an open top chamber spaced within a
closed chamber with a transparent top.
The water vapor goes into the vapor space and condenses on the seawater-cooled walls.
even if the walls are only a fraction of a degree below the evaporator temperature.
Lower evaporator temperature operation at sub-atmospheric pressure is obtained
by pulling out some air.
The vacuum (low pressure) limit depends on the strength of the structure.
You can do this with salt water in a Styrofoam cup in a jar floating in a pan of water.
About 3 pounds per square meter per hour or 15 tons/hectare-hour
under a bright sun.
Fred
