Analyzing solar panel power based on light intensity at different wavelengths

The performance parameters of a photovoltaic (PV) solar system are investigated in this study at different light wavelength, irradiance levels and temperature conditions. The electrical performance of a monocrystalline silicon solar panel, employed as the main energy conversion element, was investigated under laboratory controlled light. The characteristics are open circuit voltage (Voc), short circuit current (Isc), maximum power output, and efficiency. Spectrum fluctuations were simulated using red, blue and yellow high brightness LEDs. The irradiance was measured with a calibrated solar power meter and it was set by neutral density filters. By observing the panel surface using a thermocouple sensor and changing surrounding conditions, temperature effects were examined. Experimental results show that the PV output was strongly depending on both irradiance and spectral wavelength, shorter wavelength (blue light) contributed a higher voltage but longer wavelength (red light) generated a higer current but worse efficiency. Furthermore, the negative temperature coefficient of silicon cells meant that when the panel was heated, a significant decrease in voltage and overall performance occurred. The investigations provide valuable information in designing solar energy systems over different climatic conditions and demonstrates the influence of spectral- as well as temperature-induced effects relevant to the performance of PV.