ENERGY STAR ELIGIBILITY CRITERIA FOR RESIDENTIAL SOLAR WATER HEATING SYSTEMS
Energy Star is a joint program of the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE). In 2008, Energy Star finalized the eligibility criteria for residential water heaters, including solar water heating systems, through its residential appliance certification program. Qualifying solar water heating systems must be certified to Solar Rating & Certification Corporation (SRCC) Standard OG-300 and must, at a minimum, achieve a Solar Fraction that is equal to or greater than 0.50.
Energy Star defines Solar Fraction or SF as the energy delivered by the system divided by the electrical or gas energy put into the system. The SF is determined by the rating conditions outlined in SRCC Standard OG-300.
In addition to SRCC OG-300 certification and a minimum O.50 SF, Energy Star also requires a minimum 10 year warranty for the solar collector, six-year warranty for the solar tank, two-year warranty for the controls, and one –year warranty for piping and parts.
The SRCC rates the annual performance of a solar water heating system in terms of its Solar Energy Fraction or SEF. The SEF is the energy delivered by the solar system to the hot water load divided by the daily amount of energy used by the auxiliary water heater or backup heating element in a single tank system plus the parasitic energy used in the system by pumps, controls, or other devices. The SRCC SEF can be converted to the Energy Star SF by means of a simple formula.
Solar water heating systems with an auxiliary electric water heater or electric resistance back-up in the primary solar storage tank must achieve an SRCC SEF of 1.8 to qualify for Energy Star listing.
Solar water heating systems with an auxiliary gas heater must have an SRCC SEF of 1.2 to qualify for Energy Star listing.
For more information on Energy Star please visit: http://www.energystar.gov/