Solar Domestic Hot Water

Our Solar Collector array consists of three Heliodyne Gobi 3366 liquid solar collectors (27 square feet each) mounted on an outbuilding. These are among the most efficient thermal collectors made. The non-toxic propylene glycol coolant cycles in a closed loop to the house where it exchanges heat with our hot water tank. Though much smaller than our solar PV array, our solar domestic hot water collector array can collect just as much energy, over 25 kWh (88,000 BTU) per day.

We have an American Solar Electric Hot Water Heater in series with our propane hot water heater. (Though it has a 4500 watt electrical element, it is currently not connected to any electrical power,but may be in the future).

Energy and Monetary Savings

Energy and Dollar Savings From Solar Hot Water and Efficiency Measures

As shown by the graphs below, installing Solar Hot Water, implementing efficiency measures, and installing a wood stove cuts our propane use by ninety percent and saves us thousands in propane costs. The last graph shows water temperatures attained by our solar hot water system.

Water Temperature Data

Solar water tank temperature recorded hourly by a USB digital thermometer. The highest water temperature each day (daily peak temperature) is plotted vs Date for June 2009 through June 2010. Annual high and low temperatures are indicated on the graph.