Flexible solar from Canada
Small buildings with few electrical demands are prime targets for stand-alone solar power units. That’s the thought behind new solar technology applied to a bus shelter on the campus of McMaster University in Hamilton, Ontario, Canada. The flexible solar design was developed by a group of researchers at the school.
Silicon solar cells were custom-fabricated for this purpose and mounted on a sheet of flexible material. Much of the development work went into the method of connecting the cells “reliably and effectively,” according to Adrian Kitai, a professor on the faculty of engineering. The result is two flexible strips, each measuring 90 × 12 cm and comprising 720 solar cells measuring 1 × 1 cm each. Each strip can generate up to 4.5 W of power. The energy generated during the day is stored in batteries to light the shelter for eight hours at night.
![GL_bus.jpg](https://www.photonics.com/images/Web/Articles/2009/9/1/GL_bus.jpg)
Researchers at McMaster University in Ontario developed flexible strips of silicon solar cells that have been used to power LED fixtures in a bus shelter.
Each of the two LED fixtures that light the shelter uses 600 mW of power and produces about the same light output as a 3-W regular tungsten bulb – equivalent to a small night-light. The solar power in storage is more than enough to run the two lights throughout the night, so even if it’s a cloudy day or there’s snow on the roof, backup power is there, Kitai explained. He added, though, that the researchers have not yet made observations with 2 ft of snow on the roof, so they are not sure what the results of such long-term shading would be.
Building on their experience with flexible solar design, the McMaster team members are building integrated projects, anticipating commercial success in the not-too-distant future.
Published: September 2009