Lightguide–Lens Array Side–Absorption Concentrated Photovoltaic (CPV) System with an Extended Acceptance Angle

Abstract A lightguide–lens–array side-absorption concentrated photovoltaic system (LLA-SCPV) is proposed and experimentally demonstrated for wide-angle operation. The bottom surface of the lightguide is patterned with reflective V-grooves to direct incident light toward solar cells mounted on its sidewalls. Both the lightguide and the lens array are made of PMMA. The device exhibits a simulated acceptance angle of at least ±12° and an experimental acceptance angle of ±15°. Through an optical efficiency breakdown, manufacturing profile deviations and reduced reflectance of the V-groove facets are identified as the primary factors of the optical loss, while the V-groove profile deviations broaden the angular response. For further performance improvement, simulations under realistic industrial conditions indicate that replacing PMMA with fused silica, increasing V-groove reflectance to 0.86 and reducing the corner radius to 0.1 mm can enhance the optical efficiency to 67.7% while maintaining an acceptance angle of approximately ±15.5°.