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Solar pantaloons solve new-age warfare waste: huge piles of barely used batteries from night-sight gear and cameras: solution, Dyesol’s non-reflective 40W/sq metre fabric solar-panels

Posted by gmarkets on 3 September, 2007

Soldiers who headed into combat typically dumped partly used batteries in key equipment, such as night-sight gear, to make certain it won’t fade to black when it really mattered, reported The Australian Financial Review (31/8/2007, p.79).

Ten months ago, Sustainable Tech­nologies International, a wholly-owned subsidiary of Dyesol, began a $2 million contract for the Defence Department to create solar fabric for use in the field. Early last month, STI received $200,000 in the third of a series of progressive milestone payments. The core idea was photons of light falling on ruthenium dye knock electrons loose, generating an electric current in an adjacent layer of titanium dioxide.

Solar tents and houses: It took about a square metre of dye-sensitised material to generate 40 peak watts of power. “We reckon that a reasonably energy-efficient house would need 30-40 square metres of panels,” said Sylvia Tulloch, managing director of Dyesol. Given Australia’s minerals expertise, Dyesol saw itself as a materials and components supplier to a multiplying number of practical research laboratories and firms worldwide.

Aus solar-solution: The inevitable result, now a chronic problem in Iraq, was huge piles of barely used batteries, and a constant logistics problem keeping up the supply of replacements. Australian high-tech solar power group Dyesol, based in Queanbeyan, NSW, was being funded under the program, administered by the Defence Science and Technology Organisation, to develop camouflaged flexible solar power panels for use in the field to trickle-charge reusable batteries. They could also power cooling equipment, communications gear and sensors, as lightweight mobile powerpacks or integrated into field structures.

Inspired by vegies: The panels could be on backpacks, part of a tent, a vehicle, or laid out on the ground. The camouflage requirement was to stop the panels becoming targets for hostile aircraft or snipers, which might happen with pure silicon panels. The Dyesol technology was derived from conceptual breakthroughs by Swiss chemistry professor Michael Graetzel, now on the board of Dyesol after linking with Australian materials science couple Sylvia and Gavin Tulloch, and their colleague Hans Desilvestro. Using an approach referred to as biomimicry, or biomimetics, Graetzel worked out a process anal­ogous to the way plants use chlorophyll, a green dye in their essential lifecycle process of photosynthesis.

Nanotech process: Solar radiation falling on chlorophyll, particularly the reddish end of the visible light range and near infrared radiation, generated loose electrons which were captured by surrounding plant protein to create weak electric currents used to power the plant’s life processes. In similar fashion, photons of light falling on ruthenium dye knock electrons loose, generating an electric current in an adjacent layer of titanium dioxide. Usually known as Mania, titanium dioxide was a white pigment used in paints and toothpaste. Australia, with its titanium-bearing rutile and ilmenite beach sands, was a major industrial player in titanium products. Research over the last 15 years has shown that having the titania in the form of ultra-tiny grains (nanoparticles) magnifies the effect.

Defence Dept contract: The voids between the nancparticles were filled with an iodide/triiodide electrolyte. The whole mix, including some platinum catalyst, could be squeezed between two glass plates to generate electricity in a window pane, a glass door or a skylight.

The Australian Financial Review, 31/8/2007, p. 79

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