And assuming a person needs 0.5 gallons (2 liters) of drinkable water per day, we get that 1 square meter provides drinkable water for 15 to 30 people. Not bad!

And assuming a person needs 0.5 gallons (2 liters) of drinkable water per day, we get that 1 square meter provides drinkable water for 15 to 30 people. Not bad! Of course, once we factor in cleaning uses of unsalted water, the picture is less pretty. Still, not bad.