Australian researchers make clear, energy harvesting windows
Scientists from the Electron Science Research Institute of the Edith Cowan University in Australia have developed a solar concentration technology for making energy-harvesting glass windows.
Their approach simultaneously generates electric power through photovoltaic cells attached to glass panel edges and maintains a maximised visible-range (400-700nm) transparency.
By incorporating luminophore materials (based on molecules that emit light when illuminated) into lamination interlayers and using spectrally-selective thin-film coatings in conjunction with CuInSe2 solar cells, the group found that most of the visible solar radiation can be transmitted through the glass window with minimum attenuation. Any ultraviolet (UV) radiation is down-converted and routed with a significant part of infrared radiation to the edges for collection by the CuInSe2solar cells.
Figure a) is a schematic of the glass panel structure, b) shows several 100 x 100 mm energy-harvesting test samples. Graph c) is the modeled transmittance and reflectance spectra of the optical interference coating, employing three different optical materials, designed to serve as a "˜heat mirror' and composed of two metal layers and five dielectric layers. Graph d shows the measured transmission spectrum of the developed thin film, and the spectral power density distribution of the standard AM1.5G solar radiation transmitted through the coating-substrate system (inset).
The experimental results, published in Nature Scientific Reports, demonstrate a 10 cm x 10 cm vertically-placed energy-harvesting clear glass panel of transparency exceeding 60 percent, invisible solar energy attenuation greater than 90 percent and electrical power output near 30W/m2 mainly generated by IR and UV radiations.
The team thinks that these results open the way for the realisation of large-area visibly-transparent energy-harvesting clear glass windows for building-integrated PV (BIPV) systems.
The paper 'Spectrally selective all-inorganic scattering luminophores for solar energy-harvesting clear glass windows' by Ramzy Alghamedi et al, appears in Nature Scientific Reports 4, Article number: 6632 doi:10.1038/srep06632
