Cylindrical Fresnel lens: An innovative path toward a tracking-less concentrating photovoltaics system

We here invent an implicitly new optical device - cylindrical Fresnel lenses historically used in the decades-old lighthouse concentrator to find application in the field of concentrator photovoltaic, with numerous demonstrations of exotic features in optics. The precious attribute of such a solar concentrator is its ability to grant a focal point sequence, essentially distributed over an arc at any light incidence. The other striking merit of this design is its high acceptance angle, about 60 degrees , at hand and even up to 90 degrees, ideally. We have applied this approach to a simplified principle-of-concept model that closely depicts the octagonal cylindrical Fresnel lens in essence. This convergence feature was evidenced in a mock-up model through optical simulation and further consolidated by electrical characteristics analysis. Specifically, the simulation affirmed that an optimal structure can attain a concentration ratio of similar to 23 and an optical efficiency of similar to 70%. We indeed confirmed through an outdoor experiment a 16-fold improvement of current gain, which was close to the simulation result. Of further exceptional interest in such a design is its compatibility with two mature common tracking mechanisms: daily or yearly single-axis tracking, leaving room for design compromises. This design leaves ample margins for simple and low-cost light couplers, which are advantageous in affordable concentrator photovoltaic systems. In addition, the quantitative assessment unravelled that the generated power can be enhanced 1.3 x in comparison with the flat Silic panel. We describe the potential realization of the large-scale of the model, making this solar concentrator amenable to commercialization.

Automated summary

This article introduces a new optical device - cylindrical Fresnel lenses, historically used in lighthouse concentrators, for application in the field of concentrator photovoltaic. The solar concentrator has the ability to distribute focal points over an arc at any light incidence and has a high acceptance angle. Through simulation and experimentation, the convergence feature and current gain improvement of the new lens design were confirmed.