摘要： In the study, the daily and monthly performance of a photovoltaic thermal system integrated with phase change material is investigated in Shanghai, China. A three-dimensional model of photovoltaic thermal system integrated with phase change material system is developed and numerically simulated. Water is considered as working fluid, and the fluid flow regime is laminar and incompressible. Both quasi-steady and transient models are compared together, and the transient model is selected because of its higher accuracy. Validation analysis is performed on the numerical model to show the reasonable agreement of current research compared to some other research. After obtaining the suitable operating time for the system, the performance of the system is studied from both energy and exergy viewpoints during the year. An environmental analysis is also conducted to show the annul carbon dioxide mitigation potential. The results show that July is the best month for operating of the system in shanghai with an operating time period of 13.5 h per day on average, while November, December, and January have the lowest operating time period. The percentage of melted phase change material in January, February, March, November and December is zero which means that the melting process does not occur in these months, due to the low ambient temperature and incident solar radiation in Shanghai. Though the overall energy efficiency of the system is higher in summer, the overall exergy efficiency is lower in this season.