Evaluation of the impact of partial shading on the performance of a grid-tied photovoltaic system

Partial shading on a solar photovoltaic (PV) array is known to have a significant impact on its energy yield. This paper presents experimental measurements on a 2 kW grid-tied PV array under different shading profiles that are caused by structures of various shapes at different times of the year. A simulation method that provides an accurate description of shadow movement of the simpler structure on the array surface at different times of the day is presented. While the shade geometry can be accurately predicted, lack of knowledge about the relative amount of sunlight received by the most shaded cell in each group of cells in shunt with bypass diodes limits the simulation tool from determining the impact on the I-V and P-V curves of the array.