Measurement of electrodynamic dust shield efficiency in field conditions

In this study, two electrodynamic dust shield (EDS) prototypes were tested in the field for their dust removal efficiency using an outdoor soiling microscopy (OSM) approach. Photomicrography and image analysis were used to quantify the dust on the EDS prototypes before and after EDS activation, to determine the dust removal efficiency over periods of four days. Dust accumulation on the EDS prototypes occurred continually in the ambient environment, and the EDS function was activated once every 24 h over two rounds of testing, each round lasting four consecutive days. On average, over four days the EDS efficiency (proportion of dust mass removed) decreased from 40% to 14%. It was also found that removal efficiency was lower for particles that had spent longer time on the surface, and “old” dust from previous cycles was largely immune to removal by EDS. Also, dust removal efficiency correlated with proximity to the electrode, however this correlation weakened with exposure time. This was the first successful field test of weather-resistant EDS prototypes in the Middle East, a necessary step towards field evaluation of the EDS concept.