Understanding near sunrise and sunset PV system behaviour to identify measures to maximise effective energy yield

Photovoltaic (PV) systems have seen a steep adoption across the world, both for decentralized domestic installations and large-field centralized power plants. It is increasingly evident that PV system output is practically dependent on various interdependent ambient factors that are particularly pronounced in tropical regions. Solar radiation and ambient temperature (and therefore cell temperature) are two major factors affecting the output from any PV system. Although considerable work has been done on understanding the effect of cell temperature on the system performance, very little literature is available on the low light (low solar radiation) real-time performance of crystalline solar panels. The condition of low light is best seen during sunrise and sunset consistently. The current paper investigates this near sunrise and sunset PV system behavior, particularly for tropical conditions through an experimental set-up at the Center for Sustainable Technologies. The implication of this study is to harness the low power from the systems during such times for scheduling cleaning and maintenance.