Optical losses through gaps of CPCs with one-sided flat absorber

In this work, the angular dependence of optical losses through gaps, constructed by truncating reflectors near the absorbers, of CPCs with one-sided flat absorber was presented, and the annul radiation loss through gaps of east-west aligned CPCs is theoretically investigated. Results show that the optical losses are mainly resulted from direct radiation loss through gaps due to direct irradiation on gaps, and the loss of radiation that arrive on gaps from reflectors after multiple reflections is considerable small and can be neglected in solar calculations especially for truncated CPCs. Results also show that the annual direct radiation loss is dependent on geometric parameters of CPCs but seems independent on solar resource in sites where CPCs are used, and the annual radiation loss of full CPCs oriented in east-west direction with the tilt-angle of aperture being yearly fixed is almost identical to average optical loss of the CPC over its acceptance angle.