Renewable energy is the only long-term solution to generating energy in a sustainable manner. With sufficient number of photovoltaic installations, solar power alone can satisfy the sustainable-energy needs of the future. Since the upcoming decades will witness an unprecedented level of energy consumption, the installed capacity of photovoltaics needs to increase rapidly. However, ultimately, the shortage on available flat land area and capital expenditure could limit the number of new solar power installations. Therefore, ensuring that the existing solar power systems achieve their highest operational efficiency is extremely important.&nbsp;Currently, photovoltaic systems do not operate at their highest efficiency. Dust accumulation is the biggest challenge that is an impediment to the solar panel efficiency in all of the large-scale solar power projects in the world. Since most of the biggest solar farms are located in dust-laden desert regions due to availability of flat land and sunlight, dust accumulation is a global problem. It has been shown that under moderate soiling conditions, the efficiency of power production can drop by 30% in each month. For a typical moderate scale 150 MW solar power plant, a mere 1% drop in solar panel efficiency amounts to $250,000 loss in annual revenue. It is estimated that globally, a 3-4% efficiency drop amounts to $5 billion economic loss. Therefore, to minimize the losses, solar panels are maintained clean, conventionally by using water, resulting in consumption of more than 10 billion gallons of water per year. This is the amount of water that can serve the purposes of 3 million people for one whole year. Water consumption for cleaning solar panels is only expected to exponentially increase as the newly added solar power facilities are increasing year by year. Thus, even though we would like to think of solar power as clean energy, that is not the reality. To make solar power production sustainable and efficient, there is a pressing need for an alternate method for cleaning solar panels.&nbsp;In this paper, we propose a waterless, contactless electrostatic solar panel cleaning system. Previous attempts using interdigitated microelectrodes for electrostatic dust removal have shown some potential, but are proven to be not viable for practical application. In this work, we develop an effective electrostatic dust removal system using charge induction and repulsion. We find that dust particles, despite primarily consisting of insulating silica material, can be electrostatically repelled from electrode surfaces due to charge induction assisted by adsorbed moisture from ambient environment. We experimentally determine the charge accumulation on dust particles by conducting Stokes experiments under an electrostatic field. By comparing electrostatic forces of repulsion with Van der Waal forces of adhesion and gravitational forces, we define the electric potential for particle removal. We also show that charge induction via adsorbed moisture causes removal of dust particles over a broad range of relative humidity making our approach widely applicable to various geographical regions. Finally, we develop a lab-scale prototype and demonstrate up-to 95% recovery of lost power output using our electrostatic dust removal approach, without consuming a single drop of water.&nbsp;Electrostatic solar panel cleaning proposed in our research offers the following exciting possibilities. Firstly, as mentioned above, it consumes zero water. Secondly, electrostatic systems have negligible operational cost. Electrostatic cleaning systems for an entire solar farm with tens of thousands of panels can be operated with just a couple of dedicated panels, thus drawing zero power from the solar panel installation. Finally, the electrostatic cleaning system is modular and easily retrofittable onto existing solar panel arrays. With upcoming projects such as the huge, record breaking, $13.6 billion Dubai desert solar park, we are witnessing an exponential growth of photovoltaics. We believe that water free, sustainable, electrostatic dust removal will have a tremendous impact on photovoltaic systems around the world.&nbsp;

Electrostatic Dust Removal From Solar Panels for Waterless Power Recovery

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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