London 2012 is promising to put on the most energy-efficient Olympics ever. To be perfectly honest, the kinetic-power-lit sidewalk going in at West Ham station, forecast to generate a grand total of 21 kilowatt-hours of electricity over the course of the Games, won’t be a significant contributor to the cause.
In fact, we’d be surprised if some enterprising enviro-skeptic doesn’t step into the comments section here with an argument as to why the energy that goes into manufacturing and installing the system will likely outstrip its actual production, or about how giving up 6 extra watts of power per footstep is going to tucker out pedestrians.Still, you can’t beat it for how-about-that appeal.
The project is set for a temporary footbridge that will allow spectators to avoid passing through the West Ham station itself as they make their way from the eastbound tracks of two transit lines toward the Olympic Park.
The footbridge is being outfitted with a dozen energy-harvesting tiles from the British company Pavegen Systems. According to a Pavegen video, the slabs are made from “recycled lorry tires” and “recycled aluminum and other components.” The company says the tiles flex 5 millimeters when stepped on, and it’s this slight give that powers the system.
Pavegen is coy about the precise technology it uses. In an interview last year with the U.K. publication The Engineer, company founder Laurence Kemball-Cook said he and his team of a dozen engineers have come up with a “hybrid solution” that isn’t all about the piezoelectric effect, which takes advantage of the ability of certain materials to transform mechanical strain into an electric charge.
We’ve seen piezoelectric systems toyed with in all manner of human-powered applications, including in shoes to create power from walking, kind of like the Pavegen system.
“Piezo relies on high spikes,” Kemball-Cook said in the interview. “We know the gap between those spikes makes it very hard to give a constant flow of energy. What our technology does is reduce those gaps and give you more of a constant flow of power.”
According to an Olympic Delivery Authority press release, each footfall on the Pavegen tiles translates to 6 watts of energy that will help power 12 LED spotlights along the length of the walkway. The lights will be lit at full power for eight nighttime hours and half power the rest of the time, and with 12 million footballs during the Games the system is expected to produce an energy surplus of around 35 percent “to be stored as a contingency in batteries onboard the units.”
This isn’t the first use of the system – a video on the Pavegen site captures the installation of the tiles in a hallway at a Kent grammar school – but it’s certainly the most high-profile. Will it lead to human-powered walkways the world over?
Pavegen’s pitch is that the technology is practical, providing a “carbon-free” off-grid way to power lights and perhaps even advertising or other signage, while also being engaging – even inspiring. That’s an idea that David Stubb, head of sustainability for the London Organising Committee, has bought into.
“We want people coming to the Games to be able to do their bit for the environment and this is a great example where, literally in a few steps, people can actively contribute towards making these truly sustainable Games,” he said.