4 ms·
Nukes are extremely expensive, and take many years to build. If you are desalinating, you have absolutely no need to run it when the sun is not out. So, use ch
by ncmncm 4y ago
Nukes are extremely expensive, and take many years to build.
If you are desalinating, you have absolutely no need to run it when the sun is not out. So, use cheap solar. You don't even need photovoltaics; greenhouses suffice. You just need to move the water vapor to someplace cooler to condense out.
Pumping sea water to spread out in a coastal desert to evaporate, so the water vapor is blown up to the mountains and fills reservoirs, would be much cheaper than pumping fresh water up, and would provide hydro power besides.
You might need to bulldoze up the salt once a year.
- Gibbon1 4y agoI back of enveloped how much solar you'd need to replace water in the California Aqueduct with desalinated. Takes about 4000 kwh an acre foot. Aqueduct delivers around 3 million acre feet a year. About 1.2 X 10^13 Watt-hours. If you assume 5.5 hours of sunlight a day, 365 days a year. You get ~6 GW of solar. That's a doable number.
- ncmncm 4y agoI wonder how that compares to using a big dehumidifier on humid air. 3M acre-ft = 3.7e12 L. At 2L/kWh, that would seem to take >200 GW 24/7. Kind of makes sense... Who would bother with desalination if a dehumidifier would suffice? Is 4000 L/kWh for desalination right? Online I find 285 L/kWh for RO, yielding... 6 GW!
- Gibbon1 4y agoAn acre-foot is 1.233X10^6 liters. So 1.233X10^6 liters/acre-foot divided by 285 L/kWh is 4326 kWh/acre-foot. Checks out.
- ncmncm 4y agoWhile building out the 6 GW, every increment on the way would be incrementally more useful. Start with a 100 MW array and desalinate with that, and just keep adding to it until you are desalinating "enough". I think California announced that shading existing canals with solar, besides cutting millions of gallons of evaporation, would generate 12 GW. But investors really, really want to put all the panels out in deserts.