Design and experimental analysis of a cylindrical compound Fresnel solar concentrator

• A cylindrical compound Fresnel solar concentrator is devised and investigated.
• The devised concentrator has the advantages of good weather resistance.
• The devised concentrator has good appearance and easy modularization.
• A secondary reflector has reduced the requirement of tracking precision.

This study presents the design of a cylinder shaped solar concentrator which is comprised of an arched Fresnel lens and a Fresnel mirror and a secondary reflector. An evacuated-tube or a concentrating photovoltaic cell can be used as the receiver being placed at the focus of the concentrator. This cylindrical compound Fresnel solar concentrator may have the advantages of good weather resistance, low driving force during tracking, good appearance and easy modularization. The dimensions of the Fresnel lens and the Fresnel reflector are calculated on the basis of optical principle. An optical simulation tool is used to obtain the optical efficiency of the concentrator for different incidence angles and therefore determine the allowable tracking error. It has been found that about 90% of the incident sunlight can still be gathered by the absorber when the tracking error is within 1.5°. Discussion is also made about the influence of the solar azimuth angle on the optical efficiency. A preliminary measurement of the optical efficiency of a prototype cylindrical concentrator is introduced. The experimental data generally agrees with the simulation result.