Photonic microstructures for energy-generating clear glass and net-zero energy buildings

Abstract

Transparent energy-harvesting windows are emerging as practical building-integrated photovoltaics (BIPV), capable of generating electricity while simultaneously reducing heating and cooling demands. By incorporating spectrally-selective diffraction gratings as light deflecting structures of high visible transparency into lamination interlayers and using improved spectrally-selective thin-film coatings, most of the visible solar radiation can be transmitted through the glass windows with minimum attenuation. At the same time, the ultraviolet (UV) and a part of incident solar infrared (IR) radiation energy are converted and/or deflected geometrically towards the panel edge for collection by CuInSe2 solar cells. Experimental results show power conversion efficiencies in excess of 3.04% in 10 cm × 10 cm vertically-placed clear glass panels facing direct sunlight, and up to 2.08% in 50 cm × 50 cm installation-ready framed window systems. These results confirm the emergence of a new class of solar window system ready for industrial application.

Increasing the Energy Savings and Yield of <em>Lactuca sativa</em>, L. in Glass Greenhouses through Illumination Spectral Filtering

“…The results of customized thin-film filter development can then be used to also filter the light spectra of any conventional broad-spectrum sources. Alternatively, these filters on glass substrates can be used as components of the Electron Science Research Institute's (ESRI) recently developed transparent solar energy harvesting windows [16,17].…”

“…In order to lengthen the photo period per day in a greenhouse, many PV greenhouses use the electricity generated to power artificial lighting systems [10]. This is not efficient overall, since a product of three conversion efficiency factors (the PV efficiency, the battery storage efficiency, and the electrical-to-optical conversion efficiency applicable to the light sources) will require consideration [11,16]. Even if the most efficient electronic systems and LED components were used, the result is still not particularly efficient.…”

“…These considerations suggest that using passive optical components for filtering the natural sunlight spectrum is a more efficient approach to providing improved energy consumption, in comparison to using the most efficient of LED lighting systems. The energy balance improvements potentially offered by the use of these spectrally selective filters is further enhanced if the films are integrated into transparent solar windows [16]. Of particular interest for future research efforts will be the investigations of the combined beneficial effects on both the plant growth and the greenhouse energy efficiency, in outdoor installations employing a combination of natural lighting optimally filtered through solar window coatings, and filtered (or spectrally tuned) artificial lighting systems.…”

Photonic Crystal-Supported Long-Range Surface Plasmon-Polaritons Propagating Along High-Quality Silver Nanofilms

“…In the Introduction, we already mentioned the usefulness of the exploitation of non-oxide materials together with metal nanofilms [25,26]. (Shortcomings related with the use of broadly accepted oxide materials for such purposes, e.g., an easy oxidation of ultrathin metal layers, strong tendency of such layers to form nanoparticle islands or agglomerates in the absence of any special "wetting layers" or the like, are discussed in the same references and elsewhere).…”

“…We also profit a lot from the extensive experience of preparation of thin silver layers onto different dielectrics gained by the Australian team, especially in the course of the researches aiming at the optimization of thin film coatings for solar and thermal radiation control, see e.g., [25,26]. Important peculiarity here is the use of materials, which are not oxide materials, as adjacent layers for silver.…”