Using solar power to capture water from the air if there's no ground water left
between 1 and 3 kWh per liter of condensed water
At about 20% efficiency, worst case would need 15 meters of solar panels for one liter per hour, less than $1000 of solar panels by my calculations. So if your wetlands like where I live, dry up, large scale gardening is still possible for the price of a new car...
This experimental study demonstrates a thermodynamic cycle based on isothermal regeneration to enhance the exploitation of sorbents and low temperature energy sources, such as solar energy, for atmospheric water harvesting in dry climates. An experimental setup based on silica gel has been designed to produced liquid water with low regeneration temperatures for dry climates with dew points in the range of 2 to 8 °C and ambient temperatures between 20 and 35 °C. Experimental results demonstrate daily water production from 1.5 to 3.3 L day−1 per square meter of solar field, with a maximum regeneration temperature of 57 °C, and ambient temperatures up to 35 °C. The thermal energy required to activate the cycle is between 1 and 3 kWh per liter of condensed water.
https://www.sciencedirect.com/science/article/abs/pii/S0360544222011987
