Electric Buses: Should we buy the hype?
In a largely car-dependent country like the US, the bulk of policy and media discussion about electric vehicles tends to focus on electrifying the personal automobile. However, market and policy forces mean the hundreds of thousands of buses owned by transit agencies, school districts, and private operators might be a more economic and immediately achievable step in the clean energy transition.
Given rapid cost declines and improved reliability of battery storage, several firms already supply electric buses to agencies worldwide—so what challenges to adoption remain?
Why switch from conventional to electric buses?
- Better for the health of riders and residents
Today’s electric bus (EB) models usually range from 150 up to 350 miles per charge, so there is less cause for the “range anxiety” that may have dampened personal EV adoption. An EB spends its life driving relatively slowly along fixed routes in urban areas, using less energy per passenger and requiring less charging infrastructure compared to a car on the highway. EBs offer similar reliability and level of service as traditional ICE buses with a more comfortable experience for riders– lower to the ground, more spacious, nearly silent, and free of diesel fumes and air pollution.
Because they do not burn fuel, EBs have no diesel fumes or combustion emissions. This means a change from conventional to electric buses can significantly improve local air quality and mitigate the health risks from vehicle pollution, from increased cancer risk to asthma and other respiratory disease. Heavy duty diesel vehicles like buses are major contributors to urban air pollution because of their low fuel economy; transit buses average only around 3.25 miles per gasoline-gallon equivalent, compared to 24 mpg for cars.
EBs also run considerably quieter than diesel buses, so riders and neighborhood residents alike can expect less noise from an electric transit system. Urban noise pollution makes cities worse for everyone, but poor and minority neighborhoods, especially in more segregated cities, are disproportionately likely to bear the costs of a noisy environment with dirty air. Cities can look to an improved, electrified transit system to advance community equity and climate goals simultaneously.
2. Substantially improved energy efficiency and eliminated tailpipe emissions
Regardless of the fuel source used to generate power for an EB, they are more energy efficient and contribute fewer greenhouse gas emissions than diesel counterparts, mostly from lighter construction and reduced heat losses from regenerative braking. Even when compared to the compressed natural gas (CNG) buses many transit agencies adopted to improve emissions and fuel efficiency, EBs have about four times better fuel economy.
Because electric vehicles are “only as clean as the grid that charges them,” adoption of EBs helps promote a virtuous cycle where an increasingly electrified transportation system demands greater amounts of cheap, preferably clean renewably-generated electricity to meet relatively flexible charging needs. Localized environmental benefits can increase constituent buy-in on a public initiative that both benefits people directly in the community while also furthering greenhouse gas or other air pollution reduction targets.
3. Cheaper lifetime cost of operation
On top of significant health and environmental benefits, EBs are already cost competitive with conventional transit buses from a lifetime perspective. The higher up-front “sticker price” of EBs might initially deter transit agencies from considering a switch, but reduced fuel and maintenance costs result in net savings over the full life of the vehicle. The cost savings from switching to EBs is likely to continue increasing as battery production scales and reliable energy storage becomes cheaper and more widely available.
Because the Federal Transit Administration generally provides funding to local transit agencies for capital costs, for many cities EBs are already the cheapest option over the life of the vehicle. For example, when the Chicago Transit Authority became the first major transportation authority in the U.S. to run an electric bus, it estimated that each bus saves the city $25,000 per year in fuel costs and $55,000 in avoided healthcare costs.
4. Buses are the backbone of a high-quality, high-frequency transit system that fosters and connects walkable communities, benefitting residents, city finances, and the environment
Some readers may question the relevance of transit vehicles in the context of autonomous vehicle (AV) technology—won’t we all ride around in electric, autonomous pods courtesy of Uber or another “mobility-as-as-service” provider?
Given the urgent need to drastically reduce the vehicle emissions that greatly contribute to climate change and poor air quality, it would be unwise to plan an updated transportation system based on tech capabilities that probably won’t be widespread anywhere near soon enough.
Though AV driving would alleviate some waste and problems related to parking and the time vehicles spend sitting unused, AVs face the same physical limitation as conventional cars. They take up a lot of road space per passenger, and space is a scarce, valuable resource in even moderately dense locations.
Across generations and incomes, more Americans want to live in mixed-use, walkable neighborhoods with access to transit and the option of car-free mobility. This rising demand comes with good reason; walkable neighborhoods are in short supply because of their various health, financial, and environmental benefits.
In an increasingly urbanized future where governments will devote more resources to addressing climate change and cutting emissions, the humble bus can play a central role in providing regional mobility in a way that furthers additional policy goals, all without requiring major technological breakthroughs.
As Laura Bliss at CityLab summarizes,
“Too many cities are ignoring what is arguably the cheapest and most flexible general-purpose option, which happens to be available already: the bus.
Buses can carry large numbers of people in a compact amount of road space. They don’t require special rights-of-way (though that’s sometimes ideal). They can be deployed and rerouted as needed. Across modes, they’re the most affordable to cities in terms of capital costs, and often in terms of operations.”
Major cities around the world that recognize the health and economic costs of free road and parking infrastructure, which subsidizes the use of personal cars, are studying road pricing as policy to both alleviate traffic congestion and equitably fund transit services.
What problems have arisen for early adopters of electric buses?
As is typical during adoption of any new technology, practical issues often complicate what on paper may look like an easy and beneficial decision to transition to an all-EB transit fleet. As an executive at New Flyer, a Canadian bus maker with both conventional and electric model offerings, put it, “People worry about being an early adopter . . . [they] just don’t want a science project.”
- Environmental performance challenges
Just as extreme weather or steep elevation reduce the fuel economy of conventional ICE vehicles, electric buses can perform at greatly reduced range in less-than-ideal environments. The additional load from climbing hills and heating or cooling buses to passenger comfort across seasonal changes has strained trial battery-electric buses in places as geographically diverse as Phoenix, San Francisco, Massachusetts, Los Angeles, and Albuquerque.
Many of the agencies facing problems implementing EBs bought the vehicles from global leader BYD, though officials in Indianapolis expressed no concern with the BYD buses they already ordered despite not further electrifying the fleet. An EB study in hilly but temperate King County, Washington found mixed but generally positive performance results with nine Proterra buses.
2. Higher-than-expected charging costs
Cities like Seattle that roll out new EBs without major problems can still face financial challenges when utility rate structures that were not designed to accommodate EV charging result in more expensive fuel costs. High demand charges wiped out fuel savings for commercial and industrial vehicle customers in California, prompting Pacific Gas & Electric to propose a special rate for EVs. By offering an alternative rate structure similar to a subscription plan, the utility could “bring customer costs in line with their cost of service” saving “a transit agency 20–34 percent on what it is paying today.”
3. Safety
Although there have been few if any fires or other safety issues with EB batteries themselves, larger scale deployment of lithium-ion technology is likely to come with occasional risks. For instance, a recent fire at an APS utility scale battery storage facility in Surprise, AZ should inspire further safety precautions when designing storage or charging sites. So far though, EVs have not proven significantly more fire-prone or otherwise dangerous than conventional vehicles.
Conclusion
Despite deployment challenges and some difficulty ironing out funding structures, the transition to an all-electric bus fleet is a plausible early step in a total electric overhaul of our transportation system. Policymakers and local residents providing input to government agencies alike should advocate for the adoption electric buses, and pursue creative grant and funding sources to pay to buy and operate them.
