Optimizing bifacial PV performance: The impact of reflectors and free space luminescent solar concentrators on winter yield

In this study, we present a novel solar energy harvesting system incorporating free-space luminescent solar concentrators (FSLSCs) integrated with bifacial photovoltaic (PV) modules. The FSLSC design features a luminophore-doped waveguide, an angle- and wavelength-selective notch filter, and a Lambertian reflector, enabling efficient photon recycling. Unlike traditional luminescent solar concentrators, the FSLSC aims to emit photons into free space within a defined emission cone, enhancing light redirection towards PV modules. We developed a three-dimensional ray tracing model to analyze system performance, including different reflector configurations and emission cones. The study focuses on optimizing energy yield in urban settings, particularly during winter months, by examining the effects of diffuse and specular reflectors, and various FSLSC configurations. Our results demonstrate that FSLSCs can enhance winter energy production in the Netherlands by up to 60 %, compared to a conventional optimal tilt monofacial system. The findings highlight the potential of FSLSCs and specialized reflectors to increase PV system efficiency and offer flexible solutions for improving energy yield throughout the year, particularly during periods of high demand.