Why not use exercise bikes to supply electricity back to the grid?
Riding a stationary bicycle is great exercise. But more than one rider has wished that all that effort could be put to some use besides burning excess calories.
Now Olivier Trescases, a professor of electrical engineering, is adapting the 20 exercise bikes at Hart House to provide power to the building.
The electricity generated by each bike will be relatively modest – about enough to run two laptop computers or an incandescent light bulb, as long as someone is pedaling. Nevertheless, the power will reduce the total electricity Hart House pulls off the grid. On top of that, the conversion will help keep the gym cooler, since the electricity being fed back into the building used to be vented from the bikes in the form of waste heat.
Mostly, though, the project, which got started last year, will educate gym-goers about how much physical work is required to generate even a small amount of electricity. For example, Trescases notes that it would take about 17,000 hours on the bike to create as much electricity as can be obtained by burning a single barrel of oil. “My hope is that people will walk away and think differently about how they use electricity,” Trescases says.
Hart House facilities manager Chris Lea and former sustainability co-ordinator David Berliner approached Trescases with the idea last year. The group received a $10,000 Green Innovation Award from the Toronto Community Foundation to develop the prototype. Another $40,000 came from Live Green Toronto for software development, converting the bikes in the gym and creating an outreach program to educate youth about energy use. The Toronto Renewable Energy Co-operative is also a partner in the project.
The prototype uses a commercial exercise bike with a built-in generator that normally powers a computerized display and controls the resistance of the pedals. Trescases attached a device to the bike called a microinverter, which converts the electricity generated by the bike into 120V alternating current that can then be fed back to the building. Each bike will also be networked to a computer server, which can calculate how much electricity was generated, and display it on a terminal. Eventually, riders might be able to compete against one another, or keep track of their stats on a smartphone.
The Ontario Science Centre has had a bicycle that powers a light bulb for decades. Trescases says that the novel part of his project is that the bikes are modular – each individual bike can be connected independently to the grid – and that information about the amount of electricity generated for each bike is transferred wirelessly to a central computer.