• Energy Research

Abstract The challenge of mitigating power loss in solar photovoltaic (PV) systems—due to dust—is critical to the economical deployment of solar in arid regions. These areas suffer from high aerosol concentration levels and frequent sand storms that lead to an accumulation of a layer of dust on the surface of solar arrays. The dust stays in place due to only slight and occasional rain fall. This paper presents the results from a study conducted on the effectiveness of dry cleaning solar panels, using an automated robotic cleaning system. The robotic cleaning system is part of a research program related to robotic dust mitigation technologies for solar panels, and includes a new type of brush, which uses silicone rubber foam flaps mounted onto an aluminum core. The study found that the robotic system, using this silicone rubber foam brush, was able to effectively minimize the impact of dust on the solar panels’ power output, providing an increase in power output versus the weekly-cleaned controls. This new brush shows promise for use in solar panel dust mitigation due to its effective cleaning performance and low cost, and does not induce any damage to the surface of the solar panels.

Abstract A testbed was designed and built for studying the impact of brush-based dry cleaning on glass samples and photovoltaic (PV) solar panels. A sand deposition shaking system was integrated into the testbed to continuously deposit dust on the brushed surfaces simulating the real environmental dust conditions for a 20-year equivalent time of cleaning. The cleaning efficiency was evaluated for different types of brush materials of nylon, cloth and silicon rubber foam. In this piece of work, the focus was mainly on brushing real solar panels, which already have anti-reflective coating applied to measure the output short circuit current, which is the IV characteristics dominant factor. While some materials had a notable impact on the solar panels, no permanent or significant negative impact was found to affect the solar panels as a result of the brush-based dry cleaning with the other materials. In fact, an enhancement in the maximum power output of solar panels cleaned with silicone rubber was around 1% from the unbrushed initial power output, which could be attributed to the created surface geometry. The silicon rubber foam — a novel brush material, with no previous research literature describing its use as a brush material — provides a low cost material and allows for a simple brush design, which could reduce the cost of the brush used in robotic cleaning systems, while providing highly effective, nonabrasive cleaning.

Abstract Here, we present research addressing one of the main challenges facing the efficient production of solar energy in arid regions where solar insolation is at its highest, but where the significant challenges of pervasive dust, sand storms and insufficient rain can dramatically alter the feasibility of harvesting solar energy. In this study, the impact of dust on the light transmittance through low iron glass was assessed for different periods of time. Additionally, different cleaning mechanisms were briefly reviewed including the promising technique of dry cleaning using robotic systems. This paper explores the effect of dry cleaning for the removal of dust particles settled down on glass and the impact of brushing on the transmission of the glass. It was demonstrated that dry cleaning using Nylon brushes does not have a significant, permanent effect on the optical characteristics of the glass surface, even when the brush is used to clean a dusty surface. Significantly, the process of brushing dusty samples does improve transmittance over the un-brushed state. However, the cleaning efficiency of the nylon brushes is not as high as cleaning using water and delicate wipers. The glass samples showed some changes in the surface of the glass after brushing, however, this was shown not to have a permanent effect on the optical characteristics of the glass after the simulated equivalent of 20 years of cleaning. Therefore, the data presented in this paper demonstrates the need for careful testing in the development and assessment of dry cleaning dust mitigation solutions. It also offers an indication of the technology’s positive potential and elucidates some of the most important obstacles that need to be overcome.