Anti-soiling effect of power-enhancement coating for photovoltaic modules

Abstract

Nowadays it has received a lot of remarkable attentions that the decreasing output of Photovoltaic (PV) modules is caused by the dust accumulation influence on the glass surface of PV modules. The surface of PV modules is periodically cleaned with water in enormous PV plants. However there are some problems like the cost of maintenance and the lack of water needed to clean, especially at desert areas. Several proposals have been suggested to decrease dust accumulation on PV modules. However, those durability tests have rarely been reported. In 2010, we have reported the fundamental properties of the power-enhancement coating and results of outdoor exposure test of coated PV modules in Spain. In this paper the antireflective effect of coated PV modules and the anti-soiling effect of coated PV modules with several durability tests are reported as the interim results. It could be estimated that the coated PV modules could generate 2% more power than the uncoated PV modules due to the anti-soling effect. For the second year of outdoor exposure test in Spain, results are similar to those recovered in 2010. The average performance ratio of the coated PV modules in this period is about 1% higher than that of the uncoated PV modules. In summertime without rainfalls, dust on the glass surface of PV modules accumulates gradually and reduces power generation. By observation of these coated and uncoated surfaces of PV modules, it is obvious that the amount of dust on the coated PV modules is lower than the one on the uncoated PV modules, which indicates the antistatic effect of the coating. The antistatic effect remains after several thousand hours of some durability tests.