The Case For Solar-Powered Sidewalks
In 2006, I graduated from the Southern Alberta Institute of Technology and began working as a certified electrician, wiring houses, commercial buildings and industrial facilities. I always wanted to work on renewables and be part of the solution to climate change, but there weren’t many opportunities in my industry when I started out.
This changed in 2012, when I became an instructor at Thompson Rivers University in Kamloops, B.C. I taught in the apprenticeship program and worked with solar energy. I researched how photovoltaic, or PV, cells could convert sunlight into electricity: sunlight is made up of energy particles called photons, which these PV cells absorb and convert. What fascinated me most was how we could scale solar energy. Solar panels the size of a postage stamp already run most of our pocket calculators, while roof-sized versions can power entire homes. With TRU’s professional development funds, I enrolled in a solar training program at Solar Energy International in Colorado and created a fundamentals course on renewable energy for our students. I knew that if Canada was going to embrace clean energy, our tradespeople had to know how to install it.
In 2015, my colleague Michael Mehta, an environmental studies professor, came to me with an idea. He’d met with a Vancouver-based start-up called Solar Earth that wanted to create a proof-of-concept for ground-mounted solar panels: essentially a solar-powered sidewalk. These would be different from the solar panels you’d see on a roof. Coated in epoxy and finished with a gritty, anti-slip layer; they feel like spongier, higher-grip concrete. We got a $35,000 sustainability grant from the school and, in 2016, worked on two installations on campus: a 12-metre solar sidewalk and a solar compass, which is a decorative, sun-shaped walkway. We chose a lower-traffic, partly shaded area so students could safely practise using the installation. If this location could generate electricity, we figured, then sunnier areas could too.
When we launched the project the following year, the sidewalks produced as much as 1,850 watt-hours per day—enough electricity to power a laptop for more than two days. By the following summer, the solar compass was producing more than 10,000 watt-hours daily, which is enough to power an entire classroom of computers at TRU’s arts and education building for the day. Overall, our project generated more than 2.6 megawatt-hours in its lifetime, enough to power a house for half a year.
One of the biggest upsides of solar sidewalks is that they make use of space that goes unused much of the time. If no one is walking on a sidewalk, then it just sits there, collecting heat in the summer and needing to be plowed in the winter. We should put sidewalks to greater use. For example, if a city or a café owns a sidewalk, they could install solar panels on it and offset part of their utility bill. In Groningen, a city in the Netherlands, there’s a 400-square-metre solar sidewalk that powers the city’s municipal hall. In Copenhagen, entire bike paths are paved with solar panels, which feed 160 megawatt-hours into the country’s electrical grid annually. And, in China, there’s a one-kilometre stretch of highway lined with solar panels, which generates up to one gigawatt-hour each year—enough to power 800 homes.
For all its breakthroughs, our smaller-scale sidewalks at TRU faced some snags. We had to work around the unique challenges of sidewalk placement: shade from trees, foot traffic and making sure that the PV cells produced power. We had to cut into the concrete to lay wiring troughs and connect them to the closest source of electricity—in our case, the campus buildings. Our biggest problems came in the winter. Snow sometimes covered the panels and made generation spotty, and snowplows occasionally damaged our modules. Their heavy blades and brushes chipped away at the frame that held the panels on the ground, and the weight of maintenance vehicles—and perhaps heavy foot traffic—left visible cracks along the wireway.
Both the solar sidewalk and compass have been de-energized for some years now, because Solar Earth ended the experiment. It’s unfortunate, but I still consider the project a success. At two different points during the trial, we reviewed the performance and upgraded the technology—each time improving the panels and learning more about how to optimize them. Universities are the perfect place to pilot new technology like this, and ours were the first ground-mounted solar panels in North America. That’s something.
To scale up this kind of project in Canada, we’d need government support at every level. The groundwork is there—R&D funding, incentive programs and implementation grants for renewable energy projects already exist. Municipalities are doing what they can within tight budgets: the Malahat First Nation in B.C., for instance, recently launched a $200,000 pilot to power its administrative building with solar sidewalks, made by Solar Earth and backed by the province’s Indigenous Clean Energy Initiative. But large-scale change is slow and expensive—we still live in a world deeply reliant on fossil fuels. It’s going to take serious commitment and money to make a dent.
That’s why I’m proud that TRU backed our solar sidewalks. We kept them visible on campus, so that people would see them, ask questions and think differently about what sidewalks could be. Sometimes success isn’t measured in kilowatt-hours. Sometimes it’s in sparking curiosity and inspiring people to imagine planet-saving solutions.
—As told to Tina Knezevic
