评估安装光伏阵列屋顶的综合节能效果及影响因素

Abstract Rooftop photovoltaic (PV) systems are widely prevalent and typically deployed in an array configuration. The installation parameters of PV arrays can affect power generation and building heating and cooling loads. The magnitude of impact and underlying mechanisms have yet to be investigated. This paper presents a predictive model for PV arrays’ temperature distribution and power generation performance by coupling multi-physical fields. This model integrates the dynamic heat transfer effects on the roof caused by the intermittent shading of PV arrays, thereby facilitating a precise assessment of the overall energy-saving performance of roofs equipped with PV arrays. The results demonstrate that the temperature difference between PV panels in tilted arrays can reach approximately 10 °C, primarily due to the complex and uneven flow field distribution. Increasing the installation height to above 150 mm minimizes the temperature difference between PV panels to less than 1 °C and reduces the average temperature of the hottest panel by 8 °C. The temperature reduction leads to a 6 % improvement in power generation efficiency. The temperature of PV panels in tilted arrays is consistently 5 ∼ 10 °C higher than that in horizontal arrays, whereas tilted arrays generate more electricity than horizontal one. The overall energy savings achieved by roofs equipped with PV arrays is mainly determined by power generation and, to a lesser extent, by cooling and heating loads, while the latter’s effects become more significant in higher latitude regions. The method provides valuable guidance for designing roofs equipped with PV arrays in engineering applications.