|Water Free Cleaning Solution: Environmental Durability of Electrodynamic Screen (EDS) Films in Water-Free Cleaning of Solar Collectors|
|Annie Rabi Bernard, Ryan Eriksen, Malay Mazumder
Boston University, Boston, MA, United States
The energy output of photovoltaic power plants is greatly diminished by soiling, which is unavoidable and recurrent in semi-arid and desert regions where the power plants are predominantly located in. The current methods available to clean the solar panels require copious amount of deionized water, trained manual labor and/or robotic parts and thus are not practical for scaling up, not cost effective and are unfeasible especially in areas that have scarce water resources. The Electrodynamic Screen (EDS) film is a novel, anti-soiling, self-cleaning technology consisting of rows of parallel, conducting electrodes activated by a three phase voltage sequence. The electrodes charge the dust particles electrostatically, repel them off the surface by Coulomb force and remove them by a sweeping motion of the travelling electric field generated by the three phase design. The EDS film does not require water to operate, no manual labor and has no mechanical parts involved. The operation power consumption is 0.2 Wh/m 2 /cleaning cycle and can be harvested from the photovoltaic module itself. The EDS film can be integrated onto the photovoltaic modules and can be activated as frequently as required. We report the environmental durability, stability and operational efficiency of the EDS films made with either reflective silver electrodes or silver nanowire electrodes protected by zinc oxide. The silver nanowire - zinc oxide electrodes render the EDS film as a highly transparent structure, thereby promising an optically transparent solution for cleaning the photovoltaic modules. Results from environmental durability tests including complete water immersion, high temperatures and UV exposure are discussed. Thus the EDS film technology serves as a scalable, durable and viable solution to mitigate the energy yield loss incurred by photovoltaic power plants.