photo: MURRAY WILSON/Manawatu Standard
COLOUR THEIR FUTURE GREEN: Wayne Campbell, left, and Ashton Partridge with a tiny demonstration solar panel filled with synthetic dye. Not only is it environmentally friendly and capable of being made in New Zealand, but it costs a fraction of the price of silicon cells.
New solar cells developed by Massey University don't need direct sunlight to operate and use a patented range of dyes that can be impregnated in roofs, window glass and eventually even clothing to produce power. This means teenagers could one day be wearing jackets that will recharge their equivalents of cellphones, iPods and other battery- driven devices. The breakthrough is a development of the university's Nanomaterials Research Centre and has attracted world-wide interest already - particularly from Australia and Japan. Researchers at the centre have developed a range of synthetic dyes from simple organic compounds closely related to those found in nature, where light-harvesting pigments are used by plants for photosynthesis. "This is a proof-of-concept cell," said researcher Wayne Campbell, pointing to a desktop demonstration model. "Within two to three years we will have developed a prototype for real applications. "The technology could be sold off already, but it would be a shame to get rid of it now." The key to everything is the ability of the synthetic dyes to pass on the energy that reaches them - something that mere coloured water could not do. "We now have the most efficient porphyrin dye in the world," said the centre's director, Ashton Partridge. "It is the most efficient ever made. While others are doing related work, in this aspect we are the world leaders." The development of the dyes has taken about 10 years and was accomplished with funding from the Royal Society of New Zealand for fundamental work and the Foundation for Research, Science and Technology in the later stages. Now the team is seeking extra funding to go commercial. "This particular technology does not require the large infrastructure required for silicon chips and the like," said Professor Partridge. It lends itself to being taken up by local and New Zealand industries. Other dyes being tested in the cells are based on haemoglobin, the compound that gives blood its colour. Dr Campbell said that unlike silicone-based solar cells, the dye- based cells are still able to operate in low-light conditions, making them ideal for cloudy climates. They are also more environmentally friendly because they are made from titanium dioxide - an abundant and non-toxic, white mineral available from New Zealand's black sand. Titanium dioxide is used already in consumer products such as toothpaste, white paints and cosmetics. "The refining of silicon, although a very abundant mineral, is energy- hungry and very expensive," he said. Professor Partridge said the next step was to take the dyes and incorporate them in roofing materials, tinted window glass and wall panels where they could generate electricity for home owners. The aim was to develop a solar cell that could convert as much sunlight as possible to electricity. "The energy that reaches Earth from sunlight in one hour is more than that used by all human activities in one year."