光伏/光热与光伏发电系统的性能及节能对比分析

光伏/光热(PV/T)系统可同时产出电能和热能,具有较高的综合效率,但其生产成本和生产能耗均高于常规的光伏发电(PV)系统。以我国典型气候区的5个代表性城市的典型年气象数据为基础,基于分布参数法建立了PV系统和PV/T系统的控制方程,模拟得到二者在5个不同城市的光-电收益和光电光热综合收益。基于能量偿还时间和碳减排量,对比分析了两套系统在不同地区的节能特性。结果表明,PV/T系统的年发电量低于常规的PV系统;PV/T系统的综合效率远高于常规PV系统,其年均值在58.89%~69.91%。PV/T系统具有较短的能量偿还时间和更高的碳减排量;与常规PV系统相比,其能量偿还时间少0~0.8 a,碳减排量高3~5倍。

Comparisons of Performance and Energy-saving Features Between a PV/T System and a PV System

The photovoltaic/thermal (PV/T) system can generate electricity and heat simultaneously,which ensures high overall efficiency.However,its production cost and energy consumption are higher than the conventional photovoltaic (PV) system.In the present study,the governing equations of the PV system and PV/T system are established based on the distributed parameter method.Annual electric gain or electric & heat gain of the two systems are numerically simulated based on the typical meteorological year data in five cities of typical climatic regions of China.The results show that the annual electric gains of the PV/T system are lower than that of the PV system.The overall efficiencies of the PV/T systems are much higher than that of the conventional PV systems,and the annual average overall efficiencies range between 58.89%-69.91%.The PV/T systems have shorter EPBT and more carbon emissions reduction.Compared with the conventional PV systems,the PV/T systems can shorten the energy repayment time by 0~0.8 a and enlarg the carbon emission reduction by 3-5 times.