This is a 150-gallon, hot-water tank that holds water heated with solar water panels,
as well as a heat exchanger in the fireplace. The water is used to preheat the furnace
in the winter, and to reduce the need for the conventional water heater.
Questions and about the Gridless Urban House, its energy-efficient
technologies, and alternative-energy solutions may be directed to
questions@gridlesshome.com