Photovoltaic soiling loss in Europe: geographical distribution and cleaning recommendations

Kurzfassung

Despite being one of the major issues that photovoltaic systems face worldwide, estimating the energy and economic magnitude of soiling of solar collectors still represents a challenge. This work presents a first continental assessment of the soiling loss and of the cost-effectiveness of soiling mitigation. New soiling maps are generated through the interpolation of satellite-derived and actual data. The results show that the European countries experience an average soiling loss of 0.9%/year, with peaks higher than 3% in some southern locations, where the soiling profile is also markedly seasonal. These losses can have repercussions on the economics of photovoltaics, as unmitigated soiling can increase the levelized cost of electricity by more than 4% and reduce the net present value by more than 30 €/kW. However, the losses are also found to vary significantly in some sites from year to year, highlighting the need for continuous monitoring. The study concludes that in regions where soiling losses and electricity prices are high and the cleaning costs are comparatively low—such as in Türkiye and Spain—implementing adequate soiling mitigation measures is strongly advised. In such countries, the economic benefits achieved through the recovered energy are already higher than the cleaning costs.