Solar Energy, Vol.155, 1197-1207, 2017
Simulation of microscale particle interactions for optimization of an electrodynamic dust shield to clean desert dust from solar panels
A largely neglected aspect necessary to prevent energy losses of photovoltaic (PV) panels is efficient and cost-effective mitigation of dust soiling. A potential solution is an electrodynamic dust shield (EDS) to lift and transport dust off the PV panel via electrodynamic waves generated by electrodes on the panel surface. Accordingly, the objective of this research was to determine the effects of EDS parameters on the optimal cleaning efficiency of PV panels soiled by desert dust. A discrete element method was used to computationally simulate the transport, collision, and adhesion of charged particles, representative of dust in Doha, Qatar, subject to two-phase waves on an inclined EDS. Results showed that under given conditions, the optimal distance between electrodes (pitch) was 14 mm, which resulted from a balance between increasing pitch that aided dust transport and concomitant decreasing electric field strength that hindered transport. Optimal voltage was 2.8 kV(p-p), while particles remained adhered to the surface at small voltages (0.7 kV(p-p)) but were repelled and attracted by the same electrode at high voltages (11.8 kV(p-p)). Dust transport distance per 10 cycles generally decreased as cycle frequency increased from 0.5 to 10 Hz; however, transport distance per time was largest with an intermediate frequency of 1 Hz. Our study revealed various ways in which individual dust particles were repelled and attracted by electrodes under different conditions that produced different transport patterns, which can be used to improve the efficiency of dust mitigation for PV panels. (C) 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.orgilicenses/by-nc-nd/4.0/).