PV Gap

William Said:

wondering about desalinization of seawater....?

We Answered:

That is one idea. I´ve been thinking about a glass structure. Maybe a hybrid. A half pipe, black in the bottom to absorb sunlight and covered with glass to let light in and trap the heat. If its airtight you can use a compressor to suck the humidity out while lowering the pressure in the structure which makes it easier for more water to evaporate. The vapor sucked out is compressed into a tank until it becomes liquid again. This also raises the temperature quite alot. You use fresh, cold seawater to cool it down in a heat exchanger. Now the freshly produced freshwater should be cool enough to be pipe-lined to where it is needed. The seawater that got heated in the exchanger is pumped into the beginning of the pipe. This way to will have utilized the heat contained in the evaporated water. Watervapor <=> water + heat.
The compressors and the various pumps will consume electricity. Those can be powered by photovoltaics. Conserving as much energy as possible is key to making the thing realistic. Oh, and there are alot of places where ocean meet desert. Northafrica, Arabian peninsula, Australia, Golfo de California (Mexico), Namibia, Chile. Pumping seawater to the desalinization plant may not be the best idea. Where would you put the brine? The saltwater leftover? Some might be turned into salt but it would be better to pump it back into the ocean I think.