Electrifying transportation includes more than just passenger vehicles. Buses and trucks pose a growing threat to global climate health, making up less than 8% of vehicles, yet accounting for over a million metric tons of CO2 in 2022. Buses, specifically, emitted 452 million metric tons of CO2, up from 447 metric tons in 2021. Transitioning and retrofitting buses to electric creates a major opportunity for municipalities and schools to reduce their carbon footprint and meet state legislation. California, for example, requires that all new school bus purchases be electric by 2035.
Many cities and school districts have already taken action to rapidly transition to battery electric buses (BEBs), setting aggressive goals to decarbonize their operations. In the United States, 415 school districts and private fleet operators across 38 states committed to procuring over 12,000 electric buses in March 2022. This deal also includes converting 10,000 buses to electric over a five-year period.
Highlighting the benefits of electric buses
While gas-powered buses can reduce emissions and energy consumption for passengers who would otherwise drive a passenger vehicle, their emissions output is still high at an average of over 299 grams per mile, just behind passenger cars. The need for electric bus deployment is dire, and introducing BEBs provides many benefits beyond emission-reduction.
Lower refueling and maintenance costs
Electric buses also help transit agencies reduce refueling costs. Comparing AC Transit’s fleet of buses found that battery electric buses cost $1.61 per mile while diesel buses cost $2.29 per mile, this gap cost was further increased when considering California Air Resources Board (CARB) Low Carbon Fuel Standard credits that reduced electric bus costs to $0.53 per mile to diesel’s $2.29 per mile. With a limited number of movable parts, maintenance costs reduce as well, with CARB finding BEBs have a maintenance cost of $0.71/mile while diesel has a cost of $0.85/mile over a 20 year lifecycle. While it becomes more cost effective for school and transit authorities to replace the entire bus after 20 years, BEBs can have their battery replaced when necessary to extend its life.
Show commitment to sustainability
Electric buses can help public transit agencies and school districts hit sustainability goals by reducing greenhouse gas emissions and improving air quality. Towns like Cohasset are helping Massachusetts achieve their clean energy and climate plan goals for 2025 and 2030 by transitioning their government and school fleets to electric vehicles (EVs). Replacing all the US’ diesel buses can also eliminate more than 2 million tons of greenhouse gas emissions each year due to the lack of gas or diesel fuel use.
Stay ahead of government regulations
Like regulations for clean air passenger vehicles, many states have their own zero emission requirements for buses. CARB requirements include the transition of all public transit agency fleets to 100% zero emission buses by 2040 with a gradual transition beginning in 2023. With 13 additional states following CARB regulations, transitioning your public transit and school district’s bus fleet to electric now can keep your district ahead of future regulations.
The pathway to BEBs
The U.S. currently lags behind other regions in BEB deployments, accounting for just 2.6% of total market share globally. Holding back the transition to BEBs is the long lifespan of diesel buses, with most lasting about 12 years, along with the lower cost of diesel-powered buses. This is in comparison to the expected electric school bus lifespan of up to 15 years, with the vehicle’s battery able to be repurposed as stationary storage well after the bus itself has reached its end of life. However, bus operators will need to begin implementing clean transportation strategies for compliance with recent legislation. The pathway to BEB adoption will requires increasing federal, state and utility incentives to help transit authorities and school districts procure BEBs at reduced or no cost, in addition to providing education on BEBs and developing infrastructure and deployment strategies to support electric buses.
Preparing employees and existing infrastructure
Transit agencies and school districts will need to prepare for the transition to BEBs by providing education for drivers and maintenance workers including EV charging basics, EV range, and driving behavior. Infrastructure modifications will be needed to the existing bus depot including maintenance facilities, utility and electrical capacity, and space requirements for charging stations. More on this below.
Creating an effective BEB deployment strategy
An immediate rollout of a 100% electric fleet may not be cost effective nor efficient for public transit and school district fleets. By introducing smaller deployment projects initially and studying their effect on the overall system, including charging time statistics, out-of-service to on-the-road ratios and transit usage surveys, BEB operators can efficiently roll out buses as they become more viable for specific transit needs.
Public transit agencies and school districts require support to further transition their diesel fleets to electric buses. Enel X Way can help public transit and school district buses by streamlining infrastructure installation projects pertaining to EVSEs. By working with Enel X Way, bus fleets can optimize their depots for necessary charger capacity and vehicle rollouts.
Considerations for bus electrification
There are a few items to consider before electrifying your bus operations. Here is an overview, from selection of the right BEB and charging infrastructure, to understanding electrical requirements and optional components like battery storage and solar panels.
Selecting the right electric bus
BEBs are categorized as long-/extended-range or fast charge models depending on the battery, with long-/extended-range having battery packs ranging from 250-660 kWh for ranges well over 250 miles, more appropriate for public transit applications. Fast-charge BEB battery packs range from 50-250 kWh, provide ranges up to 160 miles and are well suited for school buses that don’t need as much range but can still charge relatively quickly due to lower battery capacity.
Public transit agencies can choose from manufacturers like New Flyer, Van Hool and Chinese giant BYD while Blue Bird, Thomas Built and Lion lead the school transportation market. Public transit buses tend to offer more range, much larger battery sizes and faster charging along with more creature comforts such as lower floors for easier passenger standing and WiFi. School buses in comparison tend to require shorter range, smaller batteries and slower charging due to their limited routes and larger time gaps between rides. Interior-wise they tend to have higher floors for bench seats and don’t generally have features like WiFi like transit buses.
Optimizing charging infrastructure
Like passenger EVs, electric buses in North America utilize both the Level 2 SAE J1772 and Level 3 CCS Combo port. In addition, SAE J3105 overhead chargers specifically for public transit buses due to their large battery size typically over 500 kW, commonly referred to as Pantograph chargers. By utilizing the common CCS Combo charging standard, public transit agencies and schools can streamline their charger deployment. Public transit agencies tend to take advantage of the faster charging methods as they typically have quicker turnaround times, requiring buses to be always staffed on route. Charging schedules also tend to occur during off-peak hours, charging overnight when at the bus depot to reduce utility costs while overhead pentagraph chargers are placed along routes for fast top-ups while on route.
Unlike public transit buses, school buses have different charging needs. School buses are utilized at the beginning and end of the school day with a large break in between, typically driving shorter distances in the local area. Unless students are engaging in extracurricular activities like field trips or sports, school buses may not need to charge as quickly to get back on the road.
Due to differing needs, school BEBs tend to have smaller batteries from 150 kWh for shorter Type A school buses up to 250 kWh for larger Type D school buses. School buses often require shorter charging times ranging from under 3 hours with compatible 100-150 kW Level 3 DC fast chargers and under 12 hours when taking advantage of 19.2 kW Level 2 chargers for a more cost-effective option.
