As part of the decathlon, teams had 10 minutes to draw 15 gallons of 110-degree water. They were required to do this several times throughout the day as a simulation of a real home's hot water use.
Solar thermal water heating systems made by companies like Apricus were employed in the Solar Decathlon houses. Apricus chief executive Mick Humphreys said that the decathlon "highlights … alternative energy technologies as a solution to residential energy needs." He also noted "the effectiveness of solar as an alternative to traditional water heating."
One of the measures by which Solar Decathlon teams were judged was the amount of hot water their house could generate.
Solar water heating isn’t limited to residential use, though. A municipal pool in Roseville, California, uses solar heating to keep the temperature at 86 degrees, says the Roseville Press-Tribune. And the Aloft Hotel in Abu Dhabi relies on solar thermal technology for 90 percent of its hot water needs.
