A comparative study on Luminescent Solar Concentrator photodegradation and hail impact resistance

Long-term reliability is a critical factor for the commercialization of semi-transparent photovoltaic panels based on Luminescent Solar Concentrators (LSCs). LSC panels are promising for renewable energy generation, but their commercialization hinges on overcoming limitations like photodegradation and hail damage. Evidence in the literature highlights how photodegradation seems to be particularly pronounced for LSCs functionalized with organic dyes, which however, thanks to their low cost, remain the most common choice for urban applications. Here, we address these challenges using glazed LSC prototypes functionalized with commercially available organic dyes of the Lumogen F family. Following the “10.15 Outdoor Exposure Test” (IEC 62108) for concentrator photovoltaic modules and assemblies, a pilot-scale batch of LSC prototypes (10×10 cm²) was exposed to natural solar radiation for extended periods to assess their long-term stability. Electrical parameters and irradiance data were continuously monitored throughout the testing period. Results showed that for initial exposure level the LSC functionalized with Lumogen F Red 305 experienced a 29% efficiency drop, whereas for higher exposure the glazed design mitigated the fluorophore degradation. Indeed, the initial decrease reached a plateau, suggesting potential long-term stability. On the contrary, the prototype with Lumogen F Violet 570 displayed minimal degradation, with only 9% reductions in power to conversion efficiency. A separate batch of samples was used to assess LSC resistance to hail impact according to the “10.9 Hail Impact Test” procedure (IEC 62108). Specimens with varying glass thickness, tempering methods, and surface areas were tested. The analysis consisted in shooting each panel with different 25 mm hailstones launched at (22.4 ± 5%) m/s. Visual inspection revealed no damage on any sample, suggesting high hail resistance. In the case of LSC panels this feature is particularly important as the hail damage may considerably affect the device performance even if the PV components remain fully operational. Our findings demonstrate that a design that combines glazed waveguides with polyvinyl butyral enhances the photostability of LSCs based on organic dyes, offering an alternative approach with respect to the utilization of more expensive fluorophores, while ensuring hail resistance in accordance with IEC 62108 directive.