High concentration thin profile solar concentrator utilizing toroidal confocal relay

•A novel solar concentrator system using cascaded type is proposed.•The concentration ratio is 2 times greater than normal designs.•The thickness of whole system is quite thin with aspect ratio of only 0.125.•The design is easy to manufacture and holds the potential for mass production.

A thin profile solar concentrator is designed based on the novel off-axis toroidal confocal relay design principle. The solar beam is collected, converged, re-collimated, and relayed to the solar cell simultaneously by the radially cascaded dielectric concentrator modules. This concentrator has properties of high concentrating ratio, thin aspect ratio, zero back focal distance, Gaussian irradiance profile, and single molding manufacture capability. In the Monte Carlo ray tracing simulation shown, one of the proposed concentrator designs has aspect ratio of 1/8 and achieves over 43100X peak concentration with the theoretical thermodynamic concentration limit, within the dielectric, of 71290X.