Linda Poon is a staff writer at CityLab covering science and urban technology, including smart cities and climate change. She previously covered global health and development for NPR’s Goats and Soda blog.
A Maryland suburb is ringing in the holidays with a message about clean energy.
On a chilly Saturday evening in a suburb just outside Washington, D.C., a crowd of kids were furiously pedaling away on a dozen bikes bolted to the base of a 35-foot Christmas tree display. We were just minutes from Silver Spring’s annual tree-lighting ceremony at the downtown plaza, and some were seriously giving themselves a full workout.
“The faster [they] pedal, the more the light array above them will light up,”said Karl Unnasch, referring to a sort of gauge that he and fellow artist Jon Taylor—the electrician of the duo—have installed above each bicycle. Not only were the riders keeping themselves warm, they also happened to be powering the town’s—and the region’s—first bike-powered holiday tree.
With holidays just around the corner, it’s always a nice surprise to see what cities have in store for one of their most festive events of the season. Some stick with tradition, letting the massiveness of the tree and the grandeur of the ornaments speak for themselves. Others choose to ring in the holidays with a bit more creative liberty.
This year, the tree in Silver Spring is green—but not just because it’s covered with brightly hued artificial grass. The installation is powered entirely by renewable energy: Solar panels are nestled between the used bikes that adorn the structure (and that will later be donated to local families). And at the top, the star of the tree is a small wind turbine. The dozen bikes from D.C.’s Capital Bikeshare have all been wired to generate enough electricity to power a 300-watt generator when they’re in use, and altogether, they’ll keep the tree’s Christmas lights lit at night. As a bonus, and perhaps a perk to get people to actually hit the pedals, each bike station is outfitted with a USB port to charge a phone.
It’s a reflection of the latest trends in U.S. cities, Unnasch told me when I met up with him early that morning as he added the finishing details with his crew. “I’ve noticed how municipal bike programs have burgeoned in the United States,” he said. “Couple that with [cities] being more conscious about the consumption of energy.”
Indeed, the most recent statistics from the National Association of City Transportation Officials reveal there are at least 55 bikeshare systems across the country, and that number is only growing as new competitors enter the market. Just last month, Silver Spring became the first suburb in the region to welcome a handful of companies bringing dockless bikes to the U.S. And with cities at the forefront of tackling climate change, dozens have committed to 100 percent clean, renewable energy sources.
All the glitz and glam of a holiday display require a lot of energy, and cities are finding ways to make them more eco-friendly. The famed tree at the Rockefeller Center in New York City takes more than 1,000 kilowatts per hour to power the 30,000 lights wrapped around it, which is actually an improvement from the 3,500 kilowatts per hour it took before the city switched to energy-efficient lightbulbs and installed solar panels. Some of the first pedal-powered trees were found in Copenhagen, which in the lead-up to the 2009 climate talks, lit its tree with 15 bicycles, and in Brisbane, U.K., official installed four bikes to power its tree. Just last year, Boston designed a tree consisting of seven rings, each lighting one at a time depending on how hard people pedaled on the two bikes at the base.
Silver Spring, like so many other towns, has long moved away from using real trees. But for a town that proudly touts its five-year program to “reimagine” the holidays, a reusable fake fir tree is, well, still too traditional. Under Unnasch, a Minnesota-based public artist who’s also designed the town’s last four displays, the plaza has been graced with trees made entirely of toys (which were then donated to local families), kitchenware, instruments, and umbrellas.
“Something like this [tree] ends up being a little more complex, a little more hands on,” Unnasch says, “or feet on, if you will.”