Office smart windows a power trip for sunlight
Offices, households and cars may soon generate power by capturing solar energy through windows fitted with a revolutionary glazing.
Kamal Alameh, an engineer at the Electron Science Research Institute at Edith Cowan University, and his research team have invented a film which harvests the sun’s energy and converts it into electricity.
The thin film lies between two sheets of glass and diverts up to 50 per cent of infrared radiation and ultraviolet rays to the edge of a treated window panel.
Photovoltaic cells at the edge of the panel capture these rays and convert them into electricity.
Professor Alameh said early tests through industry partner Tropiglas Technologies showed an office in a glass building could generate 20 per cent of its power needs through windows fitted with the film.
A more significant saving would come in reduced heating and cooling costs, with tests showing the film blocked 90 per cent of solar infrared rays and 95 per cent of thermal infrared rays without blocking natural light.
Professor Alameh, who has a PhD in photonics engineering, said the product provided energy savings because of its thermal insulation.
“This will cut down on heat entering a room, and will keep heat inside the room in winter, reducing heating and cooling costs by about 40 per cent, ” he said.
The glazing product can generate an average of 30 to 50 watts of power per square metre from solar UV and IR radiation only — a fraction of the 120 watts generated by a similar-sized PV solar panel. However, a 30-storey skyscraper has limited roof space for PVC solar panels, but could generate hundreds of megawatt hours of electricity per year through PV windows.
The product could also allow cars to generate enough power to run their air-conditioners or heaters. Because the product works with infrared and UV rays, this power could be generated even on cloudy days.
Professor Alameh said there were three aspects to the technology.
The first was a spectrally-selective, nano-engineered coating which allowed natural, visible light to pass through the glass but which blocked UV and infrared radiation.
The second aspect was micro and nano-particles that converted UV radiation to longer wavelengths and scattered infrared light to the edges of glass.
The third was a micro-engineered optical structure that allowed visible light to pass and deflected infrared radiation, routing it through multiple reflections to the edges of the panel where it was collected by photovoltaic cells and later converted to electricity.
Professor Alameh says the glazing may reach the market in about 18 months, after completing a trial in South Africa.
© The West Australian
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First published in The West Australian August 05, 2013.