Estimation of Annual Power Loss of a Solar PV System due to Rise in the Cell Temperature: A Case Study for Indian Climate

A rise in the cell temperature may cause a significant decrease in the real field power output of solar PV systems, especially in hot tropical climates such as India. A more accurate forecast of annual output is critical in the planning phase of any solar PV system or plant. The present study implements an experimentally validated 1-D transient thermal model to predict the cell temperature of PV systems. Along with the thermal model, the meteorological data of the last three years, various statistical tools, and an empirical function for PV efficiency are used to develop a framework for forecasting the PV output. When applied to a 2.72 kW poly-crystalline silicon PV array in New Delhi, the annual output is estimated to be 9.65 MWh which is 9.9% less than the forecasted ideal output. This difference is found to be 13.9% in the hot month of April and 2.8% in the colder month of January. Thus, the effect of cell temperature on the output of a PV system is immense and must be incorporated in predicting its real field output. This will enable the stakeholders to make more informed decisions regarding the installation site, PV technology, and requirement of cooling.