Forget Electric Cars, Electric Buses are Coming Fast and Furious

Author: Paul Sharman, PE, Transpo Group

Electric vehicles are the future of transportation. Look at any of the recent autoshows in the last couple of years - every car company is showcasing their new electric concept car. It goes 500 miles on a charge! It charges to 80% battery in just 30 minutes! It will drive itself! You can control it with your smartphone! The electric revolution looks promising, but it will not happen with personal vehicles first; electric buses are already supplanting their fossil fuel counterparts. This transition is happening not just in places like California and New York, they're coming to Washington state, and they're coming fast.

In just the last few months, several major transit agencies in Washington state (King County Metro, Community Transit, Ben Franklin Transit) have joined the ranks of those seeking to evaluate the feasibility of transitioning to a zero-emissions fleet. Electric bus technology has changed very quickly in the last few years, while electric buses were hardly able to drive up a steep hill 5-10 years ago to now being able to drive up to a few hundred miles on a full charge. While the pace of technological improvements is impressive, there are still some major considerations to be aware of before a full transition to electric buses is feasible. Studies conducted by the Transpo Group on electric bus feasibility find that the following items are the key elements for transit agencies to consider:

• Range Anxiety is still real - Electric buses still do not go as far as diesel buses on a full charge compared to a full tank of gas, especially in very cold environments. Battery capacities also decline with age such that the range will decrease as the bus ages. Electric bus ranges are improving (forecasts expect ~5% per year for the next decade), but 1:1 replacement of vehicles without a change in schedule is fairly unrealistic at this point. A full transition to electric is likely to impact driver scheduling. 

• Charging Takes Time - Electric bus batteries are huge. Charging at rates of approximately 150 kWh still takes 2-4 hours. 

• They're Expensive - Electric buses themselves are more expensive than their diesel or hybrid counterparts. They also require chargers. Transpo Group's recent work has shown capital cost for full fleet replacements are generally twice as expensive for electric fleets compared to diesel. 

• Electric Buses are Cheaper to Run - for two reasons. First, electric motors are simpler than fossil fuel motors (goodbye oil changes!) and wear and tear on brakes is reduced due to regenerative braking. A 2020 National Renewable Energy Laboratory study estimated that electric buses reduce maintenance costs by approximately 27 percent. Second, fueling a bus with electricity is cheaper than filling a diesel bus. This is likely to become increasingly true.

• They're Way Better for the Environment - Charging an electric bus with a relatively carbon-intense energy grid still reduces operating greenhouse gas emissions substantially. In places like Washington State that have cleaner electricity grids (thanks, hydropower!) the operating emissions for electric buses are orders of magnitude lower than diesel or hybrid buses.

Despite some of the operational drawbacks, the push for electric buses is only getting stronger. The upcoming federal infrastructure bill (which at the time of writing has not yet passed the House of Representatives) includes $7.5B for the electrification of ferries and buses. This money will greatly reduce the capital cost difference between electric buses and diesel buses.