Electric bus fleets are the latest tool for improving air quality

Proterra bus
Proterra

Concerns about air quality and vehicle emissions are rising globally. According to the Health Effects Institute (PDF), air pollution is one of the top-ranking risk factors for death and disability, with vehicle emissions the main contributor of outdoor pollution. Local and regional governments are increasingly focused on improving their ambient air quality.

Enter the electric bus

While the bus market historically has been dominated by internal combustion engines, electric buses are increasingly popular in transportation headlines. More and more, transportation agencies are setting sunset timelines for the purchase of diesel buses and announcing goals to transition to zero-emission fleets — primarily through bus electrification. The market growth making these goals possible can be attributed to China’s massive drive to establish new manufacturing chains and to electrify its own bus market over the past decade.

China’s electric bus market has seen rapid growth thanks to central and regional government support. Navigant Research estimates that sales have grown from roughly 500 battery electric buses in 2010 to nearly 163,000 in 2019, a compound annual growth rate of 78.4 percent.

China is leaps and bounds ahead of the rest of the world. According to Bloomberg New Energy Finance, China’s battery electric fleet made up over 99 percent of the global total. As an example of the country’s market strength, Shenzhen, China, has over 16,000 battery electric buses in its fleet — more than the entire bus fleet of the top five transit agencies in North America combined.

Growth outside of China

In the next decade, electric bus sales are expected to grow both in China and abroad. China’s days of rapid market growth are likely numbered thanks to market saturation and China’s recent reduction in EV incentives. Instead, rapid growth of the electric bus market is expected to come primarily from sales in markets that prioritize the reduction of greenhouse gas (GHG) emissions and other pollutants affecting ambient air quality, while also offering government support for new fleet vehicles.

North America and Europe are primed for battery electric bus growth, as both regions have air quality targets and policies encouraging fleets to replace existing buses. With the Chinese market’s adjustment to gradual growth, Chinese electric bus manufacturers are also looking for additional growth in other markets. OEMs such as BYD and Yutong already have begun shipments to fleets in Latin America.

The pros and cons of bus electrification

The presence of battery electric buses is due to more than just government policy; they have a number of benefits over conventional internal combustion engine buses. These benefits include:

  • Lower total cost of ownership (TCO): Battery electric buses can positively affect a fleet’s bottom line if managed correctly. They are expected to have lower maintenance costs than internal combustion engine buses because they have fewer moving parts and thus fewer potential points of failure. Fleets can save on fuel costs by switching to electricity over other fuels, although charging and infrastructure have to be closely managed to achieve these savings.  
  • Air quality improvements: Battery electric buses significantly improve a fleet’s air quality profile because they have no tailpipe. Any emissions related to the bus’s operation are sourced at the point of where the electricity is generated. Shifting to this technology immediately improves local air quality.
  • Lower GHG emissions: Battery electric buses improve the GHG profile of a fleet by improving the efficiency of the vehicles. Well-to-wheels, electric buses are more efficient than their ICE counterparts and have fewer GHG emissions associated with running them off grid-sourced electricity. As grids improve and reduce their carbon intensity, the operations only get cleaner. Ultimately, the operation of battery electric buses may be completely net carbon zero because they are 100 percent powered by renewable energy.

Despite these benefits, several potential roadblocks stand in the way of fleet managers moving full speed ahead toward electric bus adoption:

  • TCO and cost management: Fleets need to closely manage the charging of battery electric buses to keep costs low. Depending on use case and the required infrastructure, electricity costs may outweigh any potential savings due to the time of charging and high-powered charging needed for the vehicles to meet the use cases required of the vehicle. It is also likely that many electric buses will need mid-life battery replacements. However, the market is still in the growth stage so little data is available on when and how much this may cost fleets in the long run.  
  • Upfront vehicle costs: Even in a well-managed fleet, where the TCO for an electric bus over time is lower than an internal combustion engine counterpart, the higher upfront cost can be a hurdle for fleet managers who are hesitant to adopt new technologies. Public fleets and school districts, in particular, may have a difficult time convincing the required stakeholders that the upfront costs of electrification are worth the investment.
  • Charging infrastructure requirements: A diverse selection of charging station options available to fleets adds complexity to the electrification process. This product diversity and importance of selecting the correct chargers to obtain lower TCO adds challenges as the number of charging options can become overwhelming. Charging infrastructure also can have specific space requirements within depots that a fleet may not be ready to give up for battery electric buses.

Reducing transportation-related emissions is a global priority, electrification offers a reasonable path to reaching that goal. However, the path to improved emissions is not simple, each fleet likely will require more bespoke solutions than are available before adoption of electric buses takes off. The industry should work closely with fleets and governments to insure such a transition goes as smoothly as possible.

Learn more about fleet electrification during several sessions in the VERGE Transport conference at VERGE 19 Oct. 22-24 in Oakland, California.