Shading Effects in Photovoltaic Modules: Simulation and Experimental Results

Shade is one of the factors, which affect the characteristics and performance of solar energy systems. It can be classified either as soft or hard shade. Literature search and review were carried out, coupled with MATLAB simulation and experimentation to compare effects of shade on photovoltaic (PV) modules output power. Simulation results showed that the global maximum power points were 34.772%, 32.92%, 26.905% lower than the expected maximum power, respectively for monocrystalline, polycrystalline and amorphous PV modules. Conversely, experimental results showed that 98.2%, 97.72% and 82.2% of output power were lost respectively, for monocrystalline, polycrystalline and amorphous PV modules, when all the modules had no shade and when each module's half-area, was physically shaded by a cardboard. Conclusively, amorphous photovoltaic modules, which showed less sensitivity to both soft and hard shading cases, is recommended for use in situations where shade effects cannot be completely avoided.