Electric Bikes: a Less-Polluting Option for Commutes and Errands in the “New Normal”

October 12, 2023 | 4:39 pm
Austin Transportation and Public Works/Flickr
David Reichmuth
Senior Engineer, Clean Transportation Program

My commute now mostly consists of the distance from my bedroom to the laptop in my home office (with a short detour to the kitchen for coffee) because I’m fortunate enough to have a job and employer that allows me to work from home. But pre-COVID, most days I used an electric bike to handle the 11-mile round trip to and from the Oakland UCS office. And while I miss seeing my colleagues in person, at times I also miss my commute! Using an electric bike gave me the opportunity to get to the office as quickly as with a car, with virtually no pollution and the added bonus of some outside time. With cities moving to make streets safer for cyclists and pedestrians and the rethinking of commutes and transportation post-pandemic, more people than ever are interested in electric bikes.

E-bikes bridge the gap between conventional bikes and cars

Avoiding the use of a car (electric or gasoline) and instead choosing to bike has clear emissions benefits. But why are electric bikes important? Electric bikes serve to bridge the gap between cars and conventional bicycles. Having an electric motor means that you can take the most direct route, even if it has steep hills. It also means that you can arrive at your destination without being drenched in sweat or having to wear cycling clothes. And having electric assist means that you can carry quite a bit of cargo and still easily get the bike started and moving quickly.

For moving one person around a city, an electric bike can be far cheaper than a car, with more flexibility than most public transportation. Refueling an electric bike is cheaper than buying gasoline and there aren’t insurance or registration requirements and fees. Parking is also cheaper. Unlike my car, I’m able to park my electric bike inside my office. Considering that daily parking in downtown Oakland is $20 or more, that’s a significant savings on parking alone. And for people in apartments that have to pay for car parking, there can be savings at home too.

E-bikes are responsible for a fraction of the emissions of a car

Bikes and walking are of course zero emission, but what about electric bikes? Electric bikes (or e-bikes) are bicycles with a small electric motor that adds to the power generated from the pedals. Many e-bikes require at least some input of pedal power, but the level of assist can be changed from adding a small push to over double the power from the pedals. This assistance makes biking with cargo and cycling in hilly areas much easier, making the switch from driving to riding more enticing and practical.

However, since they are plugged in, there are climate-changing emissions associated from electricity generation. I’ve looked at this question for electric vehicles, and the answer is clear: electric vehicles result in significantly lower emissions than gasoline vehicles. And it won’t surprise you that electric bikes have much lower emissions than even electric cars. Plus, their batteries can be recycled, similar to that of electric car batteries. But how low are electric bike emissions?

It’s a bit more difficult to determine the efficiency of an electric bike, as they don’t go through government-mandated testing like gasoline and electric cars do. In addition, most e-bikes have different modes with varying levels of electric motor assist. But based on the range and battery size data from e-bike manufacturers and studies, we can determine an average energy consumption of between 1 and 4 kWh electricity per 100 miles of riding. As you would expect given the size difference between bikes and cars, e-bikes require 10 to 20 times less electricity per mile compared to an electric car (which are already much more efficient and cleaner than gasoline cars).

Riding an e-bike instead of driving a car means almost zero climate-changing emissions. The emissions shown assume a pedal-assist e-bike with 0.02 kWh/mi efficiency while riding and 90% recharging efficiency. The average battery electric vehicle requires 0.31 kWh/mi.  

When considering all of the emissions associated with electricity production riding an electric bike here in California would mean around 15 pounds of CO2 pollution per 1,000 miles of riding. By contrast, a 30 MPG gasoline car would be responsible for 787 pounds of CO2 pollution per 1,000 miles of driving and the recharging the average electric car would result in 209 lbs. per 1,000 miles. Car drivers average about 11,000 miles per year. Shifting 12% of those miles to an e-bike in California would result in the equivalent of 1,000 pounds of avoided carbon dioxide emissions.

E-bikes can be a helpful addition to mobility options

E-bikes can make the joys and access of biking more accessible for older adults and people with otherwise limited mobility, and folks who want to avoid the physical stress of biking. However, not everyone can ride a bike and even avid cyclists will have long trips or the need to transport other family members. And bad weather and poor air quality can make using an e-bike uncomfortable. But e-bikes alone don’t have to replace every trip. We still need transit and other mobility options — combining e-bikes, transit, and electric vehicles will allow us to reduce climate-changing emissions faster than electric vehicles alone.

Cities need to make space and facilities to enable people to switch from cars

Many cities are designed around the car, at least when we look at the space and infrastructure that  is given to driving and parking autos. Some US cities have made concerted efforts to expand safe biking networks. But in other places, enabling travel by biking (and walking or rolling) has often been an afterthought if considered at all. To enable people to switch from a car to an e-bike, transportation planners will need to create safe streets where everyone feels comfortable and safe while riding. Additionally, secured bike parking could help make cyclists feel more comfortable leaving their bike.

The COVID pandemic prompted cities to reevaluate how streets are used, with temporary car-free zones and the conversion of parking spaces to outdoor seating for bars and restaurants. We should continue to look for opportunities to rethink the limited street space in urban areas to enable safe alternatives to driving cars.

Some policies are making e-bikes more affordable and accessible

E-bikes cost more than similar conventional bikes, which can be a barrier to adoption. Several jurisdictions are offering incentives to make e-bikes more affordable, including targeted programs for low-income households and those in communities that lack access to other transportation options. For example, California’s E-bike Incentive Project will start providing vouchers of $1,000 to low-income households in California toward an e-bike purchase, with higher amounts available for cargo bikes and adaptive bikes. If you’re curious about a program near you, researchers from Portland State University have been maintaining a list of e-bike incentives in North America.

About the author

More from David

David Reichmuth's work focuses on analyzing new vehicle technologies and advocating for policies that support the increased electrification of transportation. Dr. Reichmuth has testified at hearings before the US House of Representatives, the California State Legislature, and the California Air Resources Board, and he is an expert on California’s Zero Emission Vehicles regulation.