Indian researchers conducted a comprehensive study of the effects of dirt on solar modules – measuring the performance degradation caused by different types of dust and bird droppings, and on modules installed at different tilt angles in the hot and dry climate of Vellore. in southern India. Their findings could allow developers to better consider and mitigate the effects of pollution during site selection and system design.
A team of scientists led by the Vellore Institute of Technology in Tamil Nadu, India, kept this in mind when they came up with a simple but effective way to study the effects of different types of contamination on photovoltaic modules. The researchers collected samples of five different soil types (black soil, desert soil, red soil, alluvial soil, laterite soil) as well as coal dust and bird droppings from different locations in India. Samples, in different amounts between 10g and 50g, were shaken and brushed onto the surface of the PV modules and the modules were tested with a solar simulator.
The results showed that at all tilt angles, bird droppings had the greatest impact on module performance, with a 50g sample taking over 80% of the modules efficiency – a significantly greater loss than any dust or soil sample caused.
The study also found that the physical properties of the soiling degree are more important than the angle of the modules when defining the degree of soiling. The results are discussed in full in the article Experimental Analysis on the Experimental analysis on the effects of the effects of lands and bird droppings on the thermal efficiency of solar panels, published in 2010. Thermal engineering case studies.
The team says its research will help improve the overall understanding of the effects of dirt on solar modules. This information could help project developers better assess site conditions and avoid locating the project in areas with particularly heavy contamination or ensure that appropriate mitigation measures can be incorporated from the outset.
However, they note that the results of this study can only be applied to regions with a hot and dry climate, similar to that of Vellore, India, on which the simulation conditions were based. In addition, climate-specific studies are needed to draw similar conclusions for other climate types.