High-Concentration Optics for Photovoltaic Applications

Abstract

The concept of a high-concentration optical system is introduced detailing the various design types and focusing only on those aimed at photovoltaic (PV) applications. This will include point focus, line focus, imaging, nonimaging, and the classical cassegrain set-up. The theory of high-concentration optics is explained in terms of idealised concepts and maximum limits for each concentrator type and combination. The optical system is broken down into the different stages and materials possible in a high-concentration configuration. The physics of reflective and refractive optics are described, and their associated errors, advantages and a brief overview of past milestones, and recent research trends in the area of high-concentration PVs are presented. Current primary and secondary optics are geometrically explained covering Fresnel, parabolic, heliostat, compound parabolic, hyperboloid, v-trough, and dome-shaped optics. This chapter also covers examples of new secondary optics, such as the three-dimensional crossed-compound parabolic concentrator and the square elliptical hyperboloid concentrator. The aim of this chapter is to provide the basic optical behaviour of high-concentration designs aimed at PV applications considering their geometry, materials, and reliability.

Conjugate refractive–reflective homogeniser in a 500× Cassegrain concentrator: design and limits

“…4 and 5, the addition of a 10% reflection loss on both dishes causes a significant drop in optical efficiency. There are materials and coatings with improved reflectance [16] such as silver (∼97% reflectance) but degradation and/or expense are common problems with such high‐quality reflective materials. All following simulations hence consider 90% reflective primary and secondary dishes so as final results are more realistic.…”

“…PMMA is the most popular polymer used in CPVs and polyethylene is used widely in other areas but has a short lifetime. Polyamide, polystyrene, acrylics and polycarbonate have been investigated but more research is required [16]. Lenses may be manufactured by hot‐embossing, casting, extruding, laminating, compression‐moulding or injection‐moulding thermoplastic PMMA [17].…”

Experimental Evaluation of a Spectral Index to Characterize Temporal Variations in the Direct Normal Irradiance Spectrum

“…2021, 11, 897 2 of 15 Photovoltaics (CPV). Such a higher sensitivity of the latter technology to spectral effects is especially noticeable when concentrated sunlight of 1000 suns or more is used in High Concentrating Photovoltaics (HCPV) [6], where multi-junction solar cells based on seriesconnected subcells with different bands of absorption are used in conjunction with optical elements [7,8]. The present contribution is mostly related to the latter type of application.…”

Fast‐Response Nickel‐Promoted Indium Oxide Catalysts for Carbon Dioxide Hydrogenation from Intermittent Solar Hydrogen

“…CO 2 hydrogenation to methanol with a steady H 2 supply has been successfully demonstrated. [5][6][7] However, the intermittent nature of solar energy will cause an unstable supply of H 2 produced by solar; [23,24] a significantly reduced catalyst response time is needed to ensure that the hydrogenation reaction can match the fluctuating H 2 flow rate. Meanwhile, the fluctuant H 2 flow rate will also cause a large variability in product distribution.…”