The Boston University project under CSP: Apollo will use laboratory-scale electrodynamic-screen self-cleaning solar technology with heliostat mirrors and parabolic troughs in large scale solar plants. The objective is to reduce both the need to clean mirrors with water and the degradation of CSP collector performance due to deposited dust. This project was announced on September 16, 2015 at the Solar Power International conference. Read the press release.
Over time, the efficiency of PV modules and solar mirrors degrades as dust covers the surface of the solar collectors. As a result, the dust blocks sunlight and reduces the amount of energy a solar plant can produce and the revenue a plant can generate. Currently, the most common method of cleaning solar collectors is by spray-washing with water and detergent. For a 300 MW plant in the southwest, more than a million gallons of water would be needed to clean solar collectors – a cost exceeding $1 million dollars every year. To counteract this problem, BU and its partners are developing a transparent electrodynamic screen (EDS) film technology that can retrofit solar collectors with a transparent film to help protect them from dust.
This project will develop new manufacturing processes that are scalable to full-size production and will conduct extensive field tests of the EDS film technology. When voltage pulses are applied to activate the EDS film, an electric field charges dust particles on the surface of the film and removes the particles by an electrodynamic travelling wave motion created by the pulsed phased voltages. The EDS film has the potential to maintain high efficiency in the solar energy system by activating the film as frequently as needed without water. The method keeps the surface of solar mirrors and panels clean, increases operational efficiency, and conserves water.