Study on the potential of a novel semi-transparent rear concentrator photovoltaic system for agrivoltaics

• A novel rear-concentrator bifacial STPV module is developed for agrivoltaic use. • Optical efficiency and transparency factor are experimentally validated. • The system provides a bifacial power gain of 1.39 under standard rear-side irradiance. • Thermal simulations show <70 °C cell temperatures under hot climate scenarios. • Thermal insulation is significantly improved for building-integrated applications. This study presents the first attempt to explore the rear-side concentrator concept through a novel semi-transparent photovoltaic (STPV) module combining dual crystalline silicon solar cells—emulating a bifacial configuration—with rear-side crossed compound parabolic concentrators (CCPCs). Designed primarily for agrivoltaic (APV) applications, the system aims to enhance energy generation while maintaining high optical transparency and improving both light quality and thermal performance. Comparative analyses demonstrate that the proposed RearCPVbif configuration significantly enhances the bifacial response, with the rear side generating more than twice the power of the front and showing clear gains over monofacial and bifacial references. The system also provides good transmission of diffuse light, with a measured visible transmittance close to 60 %, helping to reduce thermal stress and improve crop conditions in warm climates. Thermal performance remains stable, with predicted cell temperatures below 70 °C even under adverse conditions, and the insulating capacity is comparable to that of double-glazing systems. Experimental and numerical results are in good agreement for light transmission and uniformity, though discrepancies in non-uniformity highlight the need for further model refinement and outdoor testing. Finally, limitations related to increased weight and prototype fabrication with bifacial cells indicate challenges that must be overcome for large-scale implementation. Overall, these findings highlight the potential of rear-side optical concentrators to significantly enhance STPV performance without compromising transparency, offering a promising solution for energy-agriculture integration and building applications.