Waterfall

Ladies and Gentlemen: the Evaporative Cooling Generator.

On any given day, there are two air temperatures. The first is the Dry Bulb Temperature, which is measured using (you guessed it) a dry thermometer. Alternatively, one can cover the thermometer in a damp material, which results in the Wet Bulb Temperature.

The Dry Bulb Temperature will always be higher than its Wet Bulb equivalent, due to the evaporative cooling of the damp material. The greater that difference, the less humidity there is in the ambient air.

So why not harness this temperature differential? A thermoelectric generator is sandwiched between two heat sinks. The first is nakedly exposed to the air, while the other is covered with a material that absorbs water from a small reservoir.

As the water evaporates, the temperature of the Wet Bulb side plummets, while the Dry Bulb remains consistently the same. And the differential between the two translates into free electrical energy.

Questions? Comments? Concerns? Is this idea brilliant? Is it folly? Let me know.