The idea of "smart" glass with the ability to change its opacity — the amount of light that it lets through — has been with us for a couple of decades, at least. The notion has immense appeal. When installed in a building envelope, it would save costs for heating, air conditioning and lighting while avoiding the cost of installing and maintaining motorized light screens, blinds or curtains.
The technology has taken half a dozen forms, but, so far, none has been a complete success. Several have worked reasonably well, but couldn’t be brought to market at a reasonable price. As a result, the smart glass that is available is more of a novelty than anything else, although its makers and marketers would likely dispute that.
Now though, some important strides have been taken by a research consortium in Europe that feels it may have a genuine, marketable product that is getting close to market. The research project, funded by the European Union, goes by the acronym EELICON, and it has focused on innovative switchable light transmittance technology. The research group is made up of nine public and private organizations in Germany, Portugal, France, Spain and Italy, plus Hydro Quebec.
With that broadly based support, the researchers have come up with a flexible and lightweight film coated with a solution of nanocomposite polymers that give it electrochromic properties.
Nanotechnology is now at the centre of a lot of research, as scientists explore the many and surprising ways it can improve the performance of many materials. The solution that EELICON has settled on is a film that can be applied to glass from large rolls. While that can be done in the factory, it also lends itself to application on site, which opens up the possibility of retrofitting existing windows.
The research project is led by Uwe Posset, of the Center for Applied Electrochemistry at Fraunhoffer ISC, in Germany. He says his group has received the results of a life-cycle assessment (LCA) of their glass treatment. It shows that the technology can produce products using less energy than standard electrochromic (EC) windows. Now, he says, the group is working on extending the LCA to demonstrate energy savings once the EC film is actually in use.
Posset says the target price level of €200 per square metre, which is considerably less than standard EC windows based on glass. Convert that to Canadian currency and you have a price of $310/m2. A lower price may be necessary in order to compete, he says, "but €200/m2 is usually discussed…as a threshold price for competitiveness."
Posset listed the technology’s main benefits. It’s based on a film suitable for use in retrofitting. It has a switching time of less than a minute, compared to 10 to 15 minutes for glass presently on the market. And since it will be available on rolls, it makes roll-to-roll manufacturing possible. The film will go from one roll, through a coating process, then be wound onto a take-up roll.
The whole process is complex, Posset says, and is likely to need two to three years of industrial development once the research is completed. That would involve pilot projects first, then scaling those projects up for commercial production. That would require further investment of something like €10 million, or CDN $15.5 million.
When the product finally comes to market, Posset says he expects its main uses will be smart windows for energy-efficient buildings, vehicle sunroofs, smart windows for aircraft cabins, switchable doors on appliances like ovens, smart eyewear and visors.
"Huge markets will become accessible in the future if the price target can be met and minimum performance requirements are fulfilled," he says. So there is still a lot of work to be done. The product is promising so far, but it’s not yet quite ready for prime time.
Korky Koroluk is a regular freelance contributor to the Journal of Commerce. Send comments or questions to editor@journalofcommerce.com.
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