Researchers developed a new type of transparent power-generating window that combines solar-thermal-electric conversion.
Windows are a significant heat exchange channel between the outside environment and buildings. The use of windows can be done for power generation using transparent photovoltaic cells. According to studies, windows account for 50% of the energy inflow/loss from buildings. Therefore, power generation from windows can provide high energy efficiency.
The existing window power generation technologies use transparent photovoltaic cells with architectural glass. However, transparency reduces the power conversion efficiency of the photovoltaic cells.
Researchers from Shanghai Institute of Ceramics of the Chinese Academy of Sciences (SICCAS) proposed a new type of transparent power-generating window that combines solar-thermal-electric conversion with materials’ wavelength-selective absorption. The study has been described in the journal Advanced Energy Materials.
The wavelength-selective film consists of Cs0.33WO3 and resin, which possesses high visible-light transmittance of up to 88%. It allows for efficient and selective harvesting of ultraviolet and infrared lights, and converts the absorbed light into heat. Thermoelectric harvesters are aligned at the edge areas of the film to convert the temperature gradient into electricity.
According to the researchers, this power-generating system decouples the energy conversion efficiency from light transparency of the window, thus enabling independent regulation for both. Moreover, this technology can reduce the cooling load of the buildings as infrared lights are being absorbed, achieving efficient energy savings.