降尘对中国北方主要城市光伏电站发电量的影响

中国太阳能光伏发电在2010-2015年实现了飞速发展。降尘降低了光伏电池板表面玻璃的透光率，导致电池板的发电量下降。降尘对太阳能光伏发电影响的量化是预测光伏电站发电量的基础。以降尘相对较严重的北方（年均降雨量小于800mm）36个城市的光伏电站为研究对象，综合考虑温度、降尘、辐射等因素导致的光伏发电量损失，模拟了各城市光伏电站25年内的年均最大发电量。模拟结果显示：（1）36个城市平均年发电量为209.62±30.15kWh·5m^-2，其中，发电量最大的城市是拉萨，最小的为西安，前者约为后者的两倍；（2）年降雨量100~200mm地区年发电量最高，其次为≤100mm的地区，200~400mm和400~600mm的地区发电量几乎相等，600~800mm的地区发电量最小；（3）降尘与电池板最佳倾角的关系可以忽略；（4）降尘导致的光伏发电量损失最大值发生在降雨量为100~200mm区域（5.32%），然后依次为≤100mm（5.21%）、200~400mm（4.46%）、400~600mm（3.29%）和600~800mm（2.09%）的区域。

The Effect of Dustfall on the Power Output of Photovoltaic Plants Located in Major Cities in Northearn China

In 2010-2015, photovoltaic (PV) plants were booming in China. Dustfall on PV modules may decrease the transmittance of its glass and cause a significant decrease of power output. Quantization of the power output losses by dustfall is basic to predict the power output. Based on irradiation, temperature losses, dustfall and other data, this paper model the annual power output of PV plants of 36 cities (annual precipitaion <800mm) in Northern China, where the dustfall is higher than southern China. The results show: (1)The mean annual power output of the 36 cities is 209.62±30.15 kWh·5m^-2, with the maximal and minimal power outputs in Lhasa and Xi'an, respectively; (2) The dustfall almost have no effect on the optimal tilt angles; (3) The maximal power output losses by dustfall (5.32%) is obtained in regions where the annual precipitation is 100-200 mm, and the minimal power output losses by dustfall (2.09%) is obtained in regions where the annual precipitation is 600-800 mm.