Flexible solar from Canada

Anne L. Fischer, Senior Editor, anne.fischer@laurin.com

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.

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.