Specific solar energy yield

The specific solar energy yield describes the annual amount of energy supplied to the heat storage unit from 11 sq ft (1 m2) of collector surface area. Compared to other calculation results, the kind of surface (absorber, aperture or gross collector area) must always be indicated for the specific yield result.

The specific solar energy yield is often said to be the crucial parameter for measuring the capacity of a solar energy system. For a correct interpretation of this parameter, the size of the system, the solar fraction and the system losses (storage and heat distribution losses) must be considered. Solar collector ratings provided by Solar Rating and Certification Corporation and the Florida Solar Energy Center use the gross area of the collector (not the net area) in their performance efficiency rating information. ASHRAE Standard 93-2010 (for testing to determine thermal performance of solar collectors) also uses the gross area of the collector.