Electrodynamic removal of dust from solar mirrors and its applications in concentrated solar power (CSP) plants

Concentrating Solar Power (CSP) systems based on parabolic trough and power tower technologies provide inherent advantage of energy storage and high efficiency for utility-scale solar plants. The specular reflectance efficiency of the solar mirrors plays a critical role in the efficiency of electric power generation. The deposition of atmospheric dust on the surface of the mirrors reduces its reflectance efficiency and requires frequent cleaning to avoid energy-yield loss. Electrodynamic screen (EDS) can provide an efficient method for maintaining the specular reflectivity above 90% by removing the deposited dust particles. In this paper, we briefly review (1) electrostatic charging mechanisms involved in EDS, (2) optimization of EDS for high dust removal efficiency, and (3) minimization of cleaning cost and water consumption. Prototype EDS-integrated solar mirrors were produced and tested in an environmental test chambers simulating desert atmospheres. The test results show that frequent removal of dust layer can maintain the specular reflectivity of the mirrors above 90% subjected to dust deposition ranging from 0 to 10 g/m2.