Photovoltaic plant maintenance : a method base on economic evaluation of PV system losses

In literature few studies analyze the efficiency degradation due to the presence of dust on Photovoltaic (PV) modules (e.g. Meyer and Van Dyk, 2004; Hamdy et al. 2006; Powers et al. 2010; Mani and Pillai 2010). Since photovoltaic panels have to work in open space, the dust deposition cannot be avoided thus determining a reduction of energy production with respect to the clean condition. In order to quantify the effect of the reduced energy production on the payback ratio and to evaluate the long-term system performances of a photovoltaic plant, an accurate prediction of the plant efficiency and of the maintenance cost is mandatory. In this paper an economical model that takes into account the relation between the losses in the energy production (predicted by means of an electric model of a PV reference panel) and the maintenance operations cost will be presented. The opportunity of using environmental data, acquired by means of public weather station will be also discussed.