Let’s see if the claim is possible from physics and math perspective.
In one hour the water is boiled to evaporation and then cooled (I presume with some added energy).
Raw sun energy is 1375W/m2 directly hitting earth but after clouds, tilt, material absorption we could say perhaps ~25% efficiency of input energy is captured so 350W. That is 0.35KWh in one hour.
1 hour solar energy is 0.65kWh.
To raise 1C of 1ml is 1 joule. So 100C from 20C of 1000ml is 80K joules, which is 0.02kwh. 5 liters would be 0.1kwh of energy.
0.1 < 0.35. The math checks out. Should be possible to evaporate 5L of water and have some energy leftover for cooling via heatpump mechanics.
How much land would be used?
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Suppose this was put in Tampa since it’s in the sunshine state. We could say 5 hours of sunshine so 25L of clean water / m2 / day.
Average person uses 70 gallons / day or 265L/day. https://water.phila.gov/pool/files/home-water-use-ig5.pdf
Per person we’d need (265/25)= 10m2, for a city of ~500,000, we’d need 5 million m2 or 5km2.
Land area of Tampa is 300km2. So 1.6% of land would be used to make water.
5km2 is a looooot of land in one big plot, but not a lot of divided in chunks across where people live.
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If we are serious about global warming and future compfortable survival of our species then we should build homes where the entire roof is harnessing the energy of the sun.
To desalinate, to capture solar into electricity, to heat water.
Shingle roofs are strong snd cheap but if every foot of roof in US sun belt region was covered with solar cells, we’d be net negative for residential energy (produce more energy than use - that energy could supply electric transport).
It would make total sense to live in a solar farm of homes and use energy close to where it is captured.
Our future very much depends on how efficiently we can harness the sun’s energy which is free and abundant.