Rhotech Solar’s domestic solar water heater is projected to save at least 50% of domestic water heating costs.

The Background

Solar collector purchases are only one quarter of a percent of the U.S. water heater market because of the high cost of domestic solar water heaters (typically $5,000 to $10,000) and the low cost of natural gas of $150 to $200 per household per year. In order to make solar water heating more attractive, the total installed system cost must be reduced to below $1,000. At those reduced costs, the increased solar penetration would significantly decrease the use of natural gas thereby decreasing our carbon footprint. Assuming 110 million water heaters in U.S. and 50% shading, a 10% penetration of solar equates to 5.5 million installations, potentially saving 0.03 Quads of energy annually.

See “Market Potential of Low­cost Solar Water Heaters”, Jay Burch, NREL, 6/7/12

The Innovation

Rhotech’s solar water heater is constructed from thin­-film polymers and uses convection to passively move heat to a storage tank located at the top. A low-cost heat-exchanger transmits the heat from the storage tank to the high-pressure water line in your home. The complete system including a heat exchanger weighs under 10 kg when empty.