Computational Evaluation of DC Power Temperature Coefficient of a Multicrystalline Solar Photovoltaic Array for Real Field Conditions of Western Rajasthan, India

The DC power temperature coefficient as defined in literature and research papers is negative. However, in contrast to literature the computation of DC power coefficient based on the real field data of a multicrystalline Solar Photovoltaic array located at Ramgarh, district Jaisalmer of Western Rajasthan leads to positive DC power coefficient for the first time ever. The DC power temperature coefficient computation considers the relative effect of irradiance and cell temperature acting simultaneously on DC power. The computational results show that DC power temperature coefficient in percentage per degree increase in cell temperature varies between +0.8%/°C to +1.97%/°C in contrast to negative DC power temperature coefficient mentioned in literature and research papers. The wide variation in temperature coefficient is due to dependence of DC power on irradiance and wide variation in day to day irradiance. A new temperature coefficient (Pβ), based on both irradiance and cell temperature has also been computed.