Short Term Outdoor Energy Rating vs Climate Specific Energy Rating (CSER)

This study validates the Site Specific Energy Rating (SSER) of PV modules. The SSER follows the Climate Specific Energy Rating (CSER) according to the IEC 61853 series of standards, but uses a site specific meteorological profile. At first, the laboratory characterization is performed using the energy rating methodology on mono crystalline silicon heterojunction (SHJ) PV modules. Subsequently, a site specific climate profile for Freiburg, Germany, is generated using ground-based irradiance measurements. The Site-Specific Energy Rating (SSER) is then calculated based on this profile and compared with CSER results from the IEC 61853-4 data sets. For validation purposes, short-term outdoor characterizations of the same modules are conducted, capturing real-world performance. The results demonstrate a good correlation between the SSER derived from outdoor measurements and the one based on the standard methodology, with deviations ranging from 0.23% to 1.27%. However, we find that the IEC 61853-4 standard profiles fail to accurately represent locations like Freiburg, as the differences between CSER and SSER exceed the expected uncertainty. This study emphasizes the importance of incorporating site-specific climates profiles and validates, with short-term outdoor exposures, the seasonal behavior of the SSER. The findings contribute to refining the Energy Rating approach and improving the accuracy of PV module performance assessments.