New Solar Panel Cleaning Technology will be Tested at the Rotem Renewable Energy Innovation Center: Waterless Panel Cleaning
A principle problem at many solar energy installations is keeping the collection or reflection surfaces clean. With reductions in performance approaching as much as 1.5% per day, current methods using high speed sprays of demineralized water and detergent which are both expensive and labor intensive are required frequently to keep performance levels up to specifications. Dust and pollen are particular problems in arid climates where solar installations are preferred. Both become attached to surfaces and block absorption or reflection of solar energy. Now a new solution promises to keep surfaces clean without using water or labor near as often if at all.
“An ounce of prevention is worth a pound of Cure” (Ben Franklin) is the main idea behind the new device by Dr. Robert Roach and Genady Rotenberg for waterless panel cleaning. Using aerodynamic principles, dust, pollen, and sand are kept from accumulating on environmentally exposed surfaces such as solar panels, mirrors, windows, and other optical surfaces. Thus the panels remain largely free from reductions in transmissivity or reflectivity for significantly longer periods reducing the subsequent cleaning requirement to nearly zero.
Even during heat waves which plague Negev and Saharan environments, where visibility is significantly impaired by a large density of desert dust in the air and coats today’s panels with a thick layer, the solution keeps panels free from the dust. Thus, if any rain should fall immediately after, there is no dust to form a mud layer on the panel. The water simply runs off the sloping panel.
The method is also effective at preventing dew formation thus eliminating the additional problem of dew-induced dust adhesion.
The principles are currently will be tested at the Rotem Environmental Research Facility in Dimona. Dr. Roach, a former aerodynamics professor from the University of Tennessee Space Institute and Genady Rotenberg, a mechanical engineering student at the Technion are making side-by-side comparisons of two identical panels exposed to the Negev dust environment, one with the aerodynamic system and one without. Measurements from these experiments will be used to help determine the effectiveness of the system and to gauge the power requirements for the system. The current proof-of-concept system uses about 5-10 watts per square meter of panel. The theoretical requirement for an effective system is significantly less. The experiments will provide guidance and design principles for designing effective systems for all sizes of panels and establish minimum power levels. Obviously, the lower the requirement for power, the greater the return on the investment. But the estimated cost of the system and the cost of currently-used power levels are already lower than the combination of cleaning cost and improved revenue from higher power produced by a cleaner panel. Dr. Roach and Mr. Rotenberg are aiming for and ROI of less than a year for their system, even when such a system is placed on every panel in a typical solar installation.
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