Are e-bikes better for the environment?
-- Sandy McClave, New York
Well, actually, there could be. E-bike pioneer Justin Lemire-Elmore argues that e-bikes are better for the environment, at least if you compare the carbon emissions associated with producing enough extra food to fuel the rider of a standard bicycle against the emissions from coal-derived electricity used to charge an e-bike.
“Although counterintuitive that a vehicle fueled by something as dirty as coal can be considered clean and green, the fact is that food production is much dirtier,” reports Lemire-Elmore. “All things being equal, an electric bicycle produces 8.5 times less greenhouse gases than a standard bicycle.”
Lemire-Elmore argues that considerations of the carbon impact of the food we eat should take into account every step from fork to farm, including greenhouse gas emissions from creating fertilizers, operating farm machinery, delivering raw foodstuffs to factories for processing and then transporting processed goods to a final production and packaging facility before being shipped to the grocery store shelf and finally to your pantry via your car.
In fact, the average American diet produces 0.005 pounds of carbon dioxide per calorie of food produced, according to researchers from the University of Chicago. Lemire-Elmore uses this formula to assert that a bicycle commute of 15 miles each way would require the rider to consume an extra 800 calories, which in turn would produce almost 4 pounds of carbon dioxide per day (or 1,444 pounds per year). And if you charge up your bike’s battery with renewable energy (say, from the solar panels on your roof), fuhgeddaboudit! The e-bike wins every time.
Of course, there’s no question that an electric bicycle, however it’s powered, is a far better mode of transport when it comes to environmental impact than any of the other choices as well—even walking. According to research by Mirjan Bouwman of the University of Groningen in the Netherlands, traveling 1 kilometer by bike (electric or conventional) requires approximately 5 to 15 watt-hours of energy, while traveling the same distance by foot requires some 15 to 20 watt-hours. (Meanwhile, covering that kilometer in a train requires 30 to 40 watt-hours and over 400 watt-hours in a car with just the driver.) An e-bike needs only about 10 percent of the energy required to power a car and is 13 times more energy efficient than a typical four-door sedan and six times more efficient than rail transit.
The fact that it could be even better than riding a conventional bike when it comes to your carbon footprint might be just the impetus you need to justify spending the extra dollars for a newfangled “battery-assist” bike. If everyone knew that you were being even more environmentally friendly by not pedaling up that steep hill, who wouldn’t go for an electric bike? And with municipalities pouring millions of dollars into improving infrastructure for bikes and new routing apps making biking safer and more fun, now is a great time to embrace the idea of a two-wheeled commute. Maybe it’ll even convince you that it's time to get rid of that car altogether.
Resources:
The Energy Cost of Electric and Human-Powered Bicycles, by Justin Lemire-Elmore, 2004.
An environmental assessment of the bicycle and other transport systems, by Mirjan Bouwman, (2018), published on the Research Gate website.
Related:
Can we encourage commuters to take bikes?
This column was reprinted with permission. EarthTalk is produced by Roddy Scheer and Doug Moss and is a registered trademark of the nonprofit Earth Action Network. To donate, visit www.earthtalk.org. Send questions to: question@earthtalk.org.Contact StudyHall.Rocks at this address, or like us on Facebook and tell us what you think.