The Solar Panel’s Performance Dependence on Incident Radiation Intensity and its Surface Temperature

Abstract

The effect of radiation intensity and temperature on the performance parameters of a solar panel is investigated experimentally using an indoor experimental setup, designed and constructed locally at Higher Institute for Applied Sciences and Technology, Damascus. The experiments have been carried out under various intensity levels of radiation in the range of 700- 2000W/m2. The experimental results indicate that, radiation intensity has a dominant effect on current parameters. It is found that photocurrent; short circuit current and maximum current have been increased linearly with increasing radiation intensity. So, concentrating system may be regarded as a best choice to enhance the power output of solar system. The power density of the solar panel at 30oC increased from 1.86 mW/cm2 at 1300W/m2 to 3.59 mW/cm2 at 2000W/m2. The role of temperature on the electric parameters of solar panel is also considered. The practical local possible solar panel’s temperature was considered to be in the range of 10–70oC. The experiments cover this temperature range. Experimental results show that all electrical parameters of solar panel such as maximum output power, open circuit voltage, short circuit current, efficiency and fill factor have changed with temperature variation. As well as the amount of changes in these parameters in terms of temperature value have been obtained. According to results, the most significant is the temperature dependence of the voltage which decreases with increasing temperature while the current of the solar panel slightly increases by temperature. On the other hand, it has been observed that solar panel’s temperature has a dramatic effect on voltage parameters. Open circuit voltage and maximum voltage are decrease with increasing solar panel’s temperature. So, the maximum power density of the mono-crystalline and poly-crystalline silicon solar module decreased from 43.4 and 48.76/cm2 to 36.32 and 41.88mW/cm2 for temperature 10oC and 70oC respectively. When testing the effect of temperature on French Photo watt solar cells, obtained 20 years ago and encapsulated in a solar panel locally, in the temperature range of 10–90oC, it was found that, the open circuit voltage decreases by 1.87mV/ oC which is equivalent to 0.3% of the nominal value. The short circuit current intensity decreases by 20mA/oC which is equivalent to 1% of the nominal value. When comparing these values with those of the company presented at its electronic cite, Isc = +0,06%/°C; Voc = -0,34%/°C, one can conclude that aging effect is important on short circuit current intensity.