A residential solar domestic hot-water system has been installed in Dillingham as a cooperative project between the U.S. Fish and Wildlife Service Togiak National Wildlife Refuge and the UAF Bristol Bay Campus Sustainable Energy Program.
Data is being collected and analyzed partly to determine the economic feasibility of domestic solar hot water in the Bristol Bay region.
There were previous difficulties with temperature sensors which have affected the system's energy data and resulted in underestimation of actual energy production. Improvements have been made to address the problem and energy data continues to be collected and analyzed.
The system was supplied by ABS Alaskan and consists of three Heliodyne Gobi 410 solar thermal panels which heat glycol in a closed loop system. Heat is transferred to the domestic hot water system in a 108 gallon, dual-coil Stiebel-Eltron storage tank. Heated water from the tank flows through a mixing valve and directly into a Toyotomi 148 on demand oil-fired hot water heater. Any rise in temperature in the water supply will be translated into energy savings for the home. A heat dissipater is plumbed into the solar supply side to protect against overheat situations and designed to operate when the average tank temperature reaches 161 degrees F. A Heliodyne brand “Delta Pro” controller on a “Helio-flo” pump unit supplies system control and data logging capability. The system started regular operation on April 12, 2011.
Data and Analysis
Energy data is being collected to determine actual energy cost savings which should help determine the feasibility of solar domestic hot water in the Bristol Bay region. If proven to be viable, there is possibility of additional installations on USFWS employee residences or other locations. The following data is from the 2012 calendar year.
Funding and Costs
Overall cost including shipping was approximately $14,000.