Performance modelling of photovoltaic modules under actual operating conditions considering loss mechanism and energy distribution

Performance prediction and efficiency improvement are two major focuses in the research area of solar photovoltaic (PV) applications. However, the uncertainty of environmental factors and the complexity of the photoelectric conversion mechanism pose a grand challenge to accurately predict the dynamic performance of PV modules under actual operating conditions. Besides, without a clear understanding of the relationship between energy loss processes and operation conditions, it is hard to suggest specific measures for efficiency improvement. In this paper, a coupled model, which consists of an electrical model, a thermal model and an energy loss model, is developed to predict the electrical-thermal performance and quantify the power loss of crystalline silicon PV modules under actual operating conditions. To validate the coupled model, a series of experiments were implemented, demonstrating that the calculated results agree very well with the simulated ones despite sunny or cloudy days. The study demonstrates that, on a typical sunny day, the energy loss occurring in the solar cell and from cell to module accounts for 71.1% and 14.6% respectively, and more than 60%of those losses will be dissipated as heat, which has a negative impact on solar PV performance. Finally, on account of various loss mechanisms, different mitigation measures, such as how to reduce thermalization loss, are suggested for PV temperature control and efficiency enhancement.