By means of FMECA some crucial aspects for the efficiency of PV module have been put in
evidence. Among these, the paper focuses the attention on the presence of pollution and
dust on the panel surface. Such phenomenon, in fact, leads to a decrease of the transmittance of solar cell glazing and causes a significant degradation of solar conversion efficiency of PV modules. After the FMECA implementation two different steps has been followed. First the application of FMECA results has been verifies by means of a correlation between the energy reduction and the Maximum Power Point (MPP) of the PV module. Then, a sensitivity evaluation of MPP in function of the powder concentration has been analyzed and discussed.