The impact of shading on solar cell electrical parameters

Availability of light to solar cells is crucial for the efficiency of photovoltaic systems. For this reason, even partial shading can result in significant reduction of generated electric power (loss of current). This paper examines the changes in the efficiency of multicrystalline silicon solar cells which are caused by different kinds of shading. Full and partial shading were simulated by the use of three types of shutter-foils printed in a gray and black scale. The measurements of current-voltage characteristics show that totally or partially shaded modules can drastically reduce the generated power. Short circuit current decreases from about 8100 to 100 mA that in the case of the series connection of cells in a module, lead to the shift of the point of the maximum power and finally to the considerable reduction of nominal system photovoltaic power.