Helmets, roofs, window panes, benches – a Canadian engineer thinks he has found a way of converting any surface into a solar panel, using a simple spray technique.

Solar panels could soon be sprayed on to any surface

My dream is that one day you’ll have two technicians with Ghostbusters backpacks come to your house and spray your roof,” says  Illann Kramer, a post-doctoral fellow with the Edward S. Rogers Sr. Department of Electrical & Computer Engineering (ECE) at the University of Toronto and IBM Canada’s Research and Development Centre.  We have recently seen the invention of coloured solar panels, and US researchers had already begun work on a concept for printing out your own photovoltaic panels several years ago, but now, far-fetched as it may seem, Kramer has actually come up with a new technology for spraying solar cells on to flexible surfaces.  In fact Ted Sargent, Kramer’s supervisor at the University of Toronto ECE, has been trying to develop this kind of technology since as far back as 2005. He had already made considerable progress in the field and Illann Kramer claims now to have got a bit further along the same road towards a practical solar panel spray technique.

New approach to chemical coating

The ECE researcher and his team have designed a system which sprays solar cells on to flexible surfaces using miniscule light-sensitive materials known as colloidal quantum dots (CQDs). Until now, it was only possible to incorporate light-sensitive CQDs on to surfaces through batch processing – an inefficient, slow and expensive assembly-line approach to chemical coating. So Illann Kramer was keen to come up with something new on this front. In conjunction with his team he has developed a system known as ‘sprayLD’ using parts that are readily available and affordable, including a spray nozzle widely used in steel mills to cool steel with a fine mist of water. “This is something you can build in Junkyard Wars fashion, which is basically how we did it,” explains the Toronto post-doc fellow.

Potential market disruption if performance improves

This new approach should mean that a wide variety of flexible metal or plastic surfaces can be turned into solar panels, and looks set to substantially reduce the current cost of producing photovoltaic panels. Indeed if low-cost panel production techniques become widespread that might well turn the whole market upside down. It is not hard to imagine using this type of panel on a much wider scale. Surfaces which have hitherto not been suitable for installing solar panels – airplane wings being one example – could now be converted by the new CQD spray-coating method.  Having said that, the photovoltaic performance of Kramer’s spray-on panels is apparently not yet fully satisfactory and will need to be improved if the technique is to catch on. This is one of the University of Toronto team’s current objectives, the other being to facilitate mass production.

By Guillaume Scifo