Design of a Color Neutral Nonpatterned Photovoltaic Window Based on Luminescent Solar Concentrator

The necessity to fulfil buildings energy demand with different energy sources leads to an increasing integration between building components and renewable energy sources. The development of new building‐integrated photovoltaics technologies requiring less silicon solar cells for active area is particularly interesting especially from a circular economy perspective. This research describes the design of five neutral color photovoltaic windows based on large area (0.61 m2) luminescent solar concentrators co‐developed by the University of Ferrara and Eni S.p.A. The windows are installed at the Eni “Renewable, New Energies and Material Science Research Centre” in Novara (Italy). The prototypes show a visible transmittance of 38.5%, exceeding that of commercially available semi‐transparent photovoltaic technologies. Moreover, the evaluation of the window colorimetric properties highlights a color rendering index equal to 93.0, thus ensuring an excellent illumination quality of the building indoor. The panel electrical performance is measured indoor, at the end of the assembly process, and onsite, showing a power production ranging from 1.2 to 2.8 W and an efficiency between 0.23% and 0.48% depending on the illumination condition and the background reflectivity. Although the generated power is limited, it is already sufficient to power stand‐alone small appliances and smart systems. This work explores the realization of nonpatterned photovoltaic windows based on large‐area luminescent solar concentrator panels, which reduce the number of solar cells for active. These windows achieve 38.5% visible transmittance, maintaining an electrical efficiency compatible with the literature ones. A considerable added value is the color rendering index of 93.0 that ensures an excellent indoor visual comfort.