Solar water cooler is a new technology that may distinctly lessen the cost of industrial-scale air conditioning and refrigeration. These water coolers are placed on a roof and are made of three parts. The first is a plastic layer on which silver coating is put. This mirrors the incoming sunlight so that the panel doesn’t heat up and remains cool in the summer sun. The second layer is a snaking copper tube.

Water is transferred through this tube where it disperses heat to the plastic. The heat is then emanated out by the plastic at a wavelength in the middle region of the infrared (IR) spectrum. This is not assimilated by the atmosphere and travels all the way to the outer space. Ultimately, entire panel is sheathed in a thermally insulating plastic housing that verifies the heat radiated away comes from the circulating water and not the surrounding air.

Researchers at the Stanford University in California conducted an experiment. They placed three water cooling panels each 0.37 square meters on the roof of the building in the campus and circulated water through them at a rate of 0.2 liters every minute.

The result of this experiment was that the setup cooled the water 5 degree Celsius below the surrounding over 3 days of testing.  They then modeled how their panels would do if merged with typical air conditioning unit for a two-story building in Las Vegas, Nevada. The result was that their system would lessen the building’s air conditioning electrical demand by 21% over the summer.