By: Brayden Gerrard

Behind the tsunami of electric cars hitting the road, a much quieter transformation is taking place—buses are starting to turn electric.

Travelling by bus is already one of the easiest and most effective ways to fight climate change. By substituting a passenger car for a bus, an individual can reduce their travel emissions by one-third.

Electric buses offer far greater emissions reductions. A report from the Transportation Research Board found that an electric bus has 62% less emissions than a diesel bus. Consequently, converting existing diesel buses to electric ones can even have a greater impactf. However, electric buses have been slow to take off in the US, even as global sales soared. But after a slow start, US cities finally seem to be warming up to electric buses.

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Initial barriers

Global sales picked up beginning in 2014, driven almost entirely by China. In 2016, global sales peaked, with China purchasing 99% of electric buses. Despite that, the first town to deploy an all-electric bus fleet was actually American. Seneca, a town in South Carolina, converted its entire four-bus fleet to electric in 2014, when the technology was still in its infancy. With help from federal government grants, the total has since grown to six buses.

Like electric cars, electric buses cost more upfront—one report estimated that a typical diesel bus would cost about $500,000, and and an electric one about $750,000. However, electric buses are expected to produce substantial fuel and maintenance savings over their lifetimes.

Numerous barriers kept other towns from following Seneca’s lead. For one, they lacked the charging infrastructure to keep buses on the road as often as possible. Early models also suffered from limited range, making them impractical for locations in colder climates where interior heaters drain the battery more quickly.

The first experiments with electric buses hit some road-blocks as well. China-based BYD established itself as the dominant electric bus manufacturer early on, and with few options, US cities placed nearly all their initial orders with BYD. A Los Angeles Times investigation later found the buses suffered from poor performance and frequent mechanical problems.

New solutions accelerate adoption

While early models struggled, newer models have significantly improved performance. A report from the World Resources Institute showed considerable improvements in range, efficiency and availability in a study of electric buses in Shenzhen, China.

A Toronto Transit Commission Proterra electric bus

Other manufacturers have also joined the market, giving cities more options to choose from. Established manufacturers such as Volvo, Daimler and New Flyer, as well as new entrants like Proterra and Greenpower, soon brought models to market. Many of the newer models are also offering increased ranges—Proterra’s ZX5 model has more than twice the range of the BYD K9.

Transit agencies have also deployed some innovative solutions, such as on-route charging. Buses must usually return to the depot to be recharged—a process that keeps them out of action for anywhere between one and eight hours.

However, cities can keep buses on the road for longer by using on-route charging. With high-powered chargers at bus stops, the bus can receive a charge while passengers load and unload. These chargers can be placed overhead, connecting to the roof of the bus once it stops, or in the ground, where the bus is charged wirelessly. By boosting the charge along the way, the buses can be kept on the road as long as required without needing a huge battery.

With more options and better performance available, North American cities are finally making the switch. After almost zero electric bus sales in 2015, nearly 800 were sold in the US and Canada in 2020. Los Angeles is leading the charge, aiming to convert its entire fleet to electric by 2028. By 2040, all of California intends to do the same.

Other cities are also joining the trend. New York City, with the largest fleet of buses in the country, aims to be all-electric by 2040. Across the country, the managers of the ten largest bus fleets have all made the decision to purchase at least one zero-emission bus.

Progress still to be made

The US remains a long way from a complete transition. At the end of last year, about 2700 electric buses were either delivered or ordered— about 4% of the national fleet, according to Federal Transit Administration data.

Part of the delay is the long life-span of a diesel bus—many transit agencies plan for their diesel buses to last 12 years, meaning it will take some time before all existing buses require replacement. The limited track record of electric buses also makes some transit agencies hesitant to invest heavily. Many transit agencies have purchased small quantities to test feasibility, delaying broader adoption until they are more confidence that electric buses can meet their needs.

However, electric buses are about to get some help from the federal government. The recently passed Build Back Better Act allocated $7.5 billion for the purchase of electric buses, which should encourage many sceptical transit agencies to make the leap.

Public transit remains essential to decarbonisation. With electric buses, the potential of public transit is more attractive than ever. As battery costs decline and technology continues to improve, more transit agencies will decide to convert their fleets to electric. Within a couple decades, diesel buses could be a relic of the past.