Comparative Analysis of Electrical Parameters of PV Modules Based on Measurements under Laboratory and Real Operating Conditions

Abstract

This paper presents a comparative analysis of electrical parameters of photovoltaic modules determined under laboratory and real operating conditions. The study was conducted for two PERC-type crystalline silicon modules using a solar simulator (Endeas 650Lab) and a portable measurement system (Benning PV2 and SUN2). The main electrical parameters were determined and converted to standard test conditions (STC). The obtained results indicate good agreement between the two measurement methods, with differences not exceeding a few percent for most parameters. At the same time, it was shown that environmental conditions, in particular module temperature, may lead to significant discrepancies in the results. The inaccuracy of temperature determination under real operating conditions was identified as one of the main sources of measurement errors. Additional investigations demonstrated that the use of a thermal shield for the temperature sensor reduces the influence of external factors, such as wind, and improves the agreement between measurement results. The results confirm that portable measurement systems can be effectively used for PV module diagnostics, provided that appropriate measurement procedures are applied and sources of uncertainty are properly considered.