An impact of fly ash on photovoltaic panel performance in the built environment: A case study.

• Power drop values for horizontal PV panel were in the interval 7.2–87.2%. • Power drop values for optimal PV panel were in the interval 7.2–30.6%. • Fly ash caused PV power drop was greater in periods with no precipitation. • For 1 day without rain, the additional power drop of horizontal panel was 0.4–10 %. • For 1 day without rain, the additional power drop of optimal panel was 0.2–9.1 %. Fossil fuels are mostly utilized for heat generation in Serbia throughout the heating season in the built environment which usually lasts 6 months every year, thus fly ash often accumulates on photovoltaic (PV) panels decreasing their performance. This paper analyzes results of the outdoor experiment conducted at the Faculty of Sciences and Mathematics in Niš investigating the influence of deposited fly ash on power (P) drop for horizontally and optimally inclined PV panels during three heating seasons in the City of Niš. Innovations of the paper are reflected in concrete data of P drop for short time periods in real outdoor environment, additionally connected with precipitation values which represent natural way of panels cleaning, that are all together not frequent in available literature especially for continental climate regions. The experiment showed that for only one day without precipitation, the P drop for the horizontal panel rose by an extra 0.4–10 %, and 0.2–9.1 % for the optimal panel. Experimentally measured data in this paper are of high importance not only for showing the P loss of PV panels in soiling conditions and the necessity of periodical cleaning, but also for their utilization in urban PV plants design and further simulations and calculations. [ABSTRACT FROM AUTHOR]