Friday, June 12, 2009
There won't be anymore waiting in the dark at this campus bus
shelter. New flexible solar cell technology developed by a group of
engineering researchers at McMaster University has been installed
to power lighting for night-time transit users.
The researchers are also hoping that the prototype will help boost
efforts to commercialize the new technology. The bus shelter is
located on the west side of University Avenue between the John
Hodgins Engineering Building and the Life Sciences Building.
"Our goal is to provide a clean, affordable power source for bus
shelters that will let transit companies run Internet-based
scheduling updates," said Adrian Kitai, a professor of engineering
physics at McMaster who guided the project. "The solar technology
can also be used to light up bus shelter signage and provide
lighting for general safety."
The flexible solar cell project started as a master's thesis for
Wei Zhang, who subsequently worked as an engineer in the Department
of Engineering Physics. Julia Zhu, a research technician in the
department, and Jesika Briones, a master's of engineering
entrepreneurship and innovation graduate, also helped develop the
initiative.
The ability to bend the solar cells to fit the curved roof of the
bus shelter is one of the main features of the technology. The
flexibility is achieved by tiling a large number of small silicon
elements into an array, mounting them onto a flexible sheet, and
connecting them through a proprietary method. The two solar strips
installed on the McMaster bus shelter are about 90 centimeters long
and 12 centimeters wide. Each strip has 720 one-centimetre square
solar cells and generates up to 4.5 Watts of power.
With the help of Facility Services at McMaster, a solar strip was
mounted at each end of the bus shelter roof and connected to two
energy-efficient, multi-LED, light fixtures. Each light fixture
uses only 600 milliwatts of power and produces about the same light
output as a three watt regular tungsten bulb or what a small night
light would use. The lights are bright enough for easy
reading.
The solar cells capture sunlight during the day and convert it to
electricity to recharge batteries located in each lighting unit.
The batteries can hold enough charge to light the shelter for the
better part of a night.
The solar cell research team is monitoring the installation to
determine how much solar power is required to fully recharge the
batteries based on weather conditions. Winter months will be a
particular focus as shorter and overcast days, snow and cold can
affect the charging ability of the solar cells and batteries.
Funding for the initiative was provided through an NSERC strategic
grant and an NSERC I2I grant.
The team is interested in hearing from transit riders about their
experience with the lit bus shelters, and any suggestions they may
have.
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McMaster University
Thanks to McMaster University for this article.