High-integrated spectral splitting solar concentrator with double-light guide layers

Abstract

Abstract. Individual secondary optical components in a spectral splitting solar concentrator utilizing a microlens array require multiple photovoltaic (PV) cells, which leads to the complexity of system alignment and a high cost. In order to improve the integration of the PV cells and thermal management, a spectral splitting concentrator coupled to double-light guide layers has been proposed. Using one-axis tracking, we further investigate the optical performance of the concentrator combined with a cylindrical microlens array with double vertically staggered light guide layers in detail. The results show that this solar concentrator maintains a good acceptance angle of AE2 deg in the east-west direction and an acceptable angle of AE14 deg in the perpendicular direction on both low and high spectrums, achieving a concentration ratio of 10×. Finally, the capability of lateral displacement tracking has been explored for an aperture angle of AE24 deg in this concentrator. IntroductionWith the promotion of solar energy utilization, solar concentrating technology which increases the energy collecting efficiency has been rapidly developed and photovoltaic (PV) cells are generally identified as the most important components in a concentrator photovoltaic (CPV) system to realize photoelectricity power conversion.1 To convert a large portion of the incident solar spectrum, a series of PV cells have been constructed by layering semiconductors with different absorption characteristics, manufactured by complex and high-cost multijunction technology.2 Therefore, spectral splitting technology with a low-cost multiple single-junction PV cells has more potential applications due to the low concentration ratio and high photoelectricity conversion efficiency. The single module using spectral splitting technology obtains a high photoelectricity conversion efficiency of 42.7 AE 2.5% combined with an optical efficiency of 93%.

Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications

“…A planar, self-tracking solar concentrator system with an acceptance angle of over 40°is also demonstrated, which can achieve 150× effective concentration for a reasonably sized concentrator [8]. In the spectral splitting solar concentrator with double-lightguide layers, the capability of lateral displacement tracking has been explored for an aperture angle of 24° [9]. A two-axis tracking scheme realized by a single-axis mechanical tracker and a translation stage is designed for <250× concentration with an 0.5°i ncidence angle, which has two-dimensional x-y tracking instead of horizontal movement in the x direction only [10].…”

Periodic microstructures for improved lens-to-waveguide coupling efficiency in microlens array planar solar concentrators

“…[6][7][8][19][20][21] However, designs that utilize a change in the waveguide cross-section are inherently aperiodic and are difficult to fabricate with reduced cost and with a scaled-up the output power. 22 utilizes a stepped lens array with efficient spectral splitting. 19 requires an additional secondary coupler over which no collection is possible; this reduces the capture area and hence, the total efficiency.…”