REAL ENERGY PRODUCTION OF RESIDENTIAL PHOTOVOLTAIC SYSTEMS

Abstract

The real energy production of photovoltaic (PV) systems differs significantly from predictions which are based on standard test conditions (STC) for PV-modules. By taking into account the physical differences between real boundary conditions and STC, energy prediction becomes possible with high precision. The most important effects such as non-vertical incidence of real solar radiation, the real means of solar radiation and the means of real module temperatures will be investigated and their influence on energy production given. Based on these findings, a simple method will be presented for the prediction of the modules ‘ energy production which is based on solar radiation data, the modules’ peak power and a quality factor QM. In a next step the quality factor for PV systems will be presented and compared with real data from European PV plants and the German 1000-roofs project. It will be shown that the quality factor is ideally suited to determine the systems-engineering quality of a PV plant independent...