Category: Utility Scale Generation
Natural dust deposition, called soiling, and the loss of output power due to the decrease in collected irradiance, can be a significant challenge for solar power plant operators in arid climates. The current industry standard is deluge or brush washing, which can consume significant volumes of water, disrupts plant operation, and is labor intensive. These factors may limit the growth of solar power in arid climates if a water-free method of cleaning cannot be achieved. Passive hydrophobic coatings have a limited lifetime and still require water, while robotic cleaning has a potential for failure due to the moving parts and the dusty environment. Furthermore, the timing of the cleaning schedule can have dramatic impacts on the overall performance ratio of a solar field. The Electrodynamic Screen (EDS) film consists of rows of interdigitated electrodes that is then installed on the surface of the solar collector. When the EDS is activated by an external power supply, an electric field charges and then sweeps dust particles from the optical surface. Cleaning with the EDS system has been shown to restore the output power of a photovoltaic panel to 95% of its original output, and to restore the specular reflectance of a solar mirror to 90% of its original output in laboratory tests. Furthermore, the EDS can clean more frequently than other soiling mitigation techniques, allowing or an improved performance ratio. Work is now underway to test the EDS in solar fields in the southwestern United States and in international locations. Automated testing setup designed to collect the data remotely have been deployed, with plans to install a trial set on full size PV panels retrofitted with EDS in an existing solar field by the end of 2019.
Ryan Eriksen– Postdoctoral Associate, Boston University