Electric school buses for regional WA: Challenges and solutions

Could electric buses replace diesel-powered school buses in regional and remote Western Australia? That was the topic of investigation in a recently completed iMOVE project, Electric school buses for Western Australia: Feasibility study.

While electric vehicles (EVs), including buses, work well in metropolitan areas with strong electricity grids, the picture was unclear for the state’s regional and remote areas. Uncertainties included the different operating conditions (ie dusty gravel roads, longer distances), possible power outages and weaker feeders into the electricity grid. This work investigated the technical and economic feasibility of electric school buses meeting greenhouse gas emission (GHG) targets and eliminating children exposure to bus exhaust in rural and regional Western Australia (WA).

This research was commissioned by the Department of Transport (Western Australia), working with the Public Transport Authority, with the research conducted by the Planning and Transport Research Centre (PATREC).

Objectives

The project assessed the technical feasibility of replacing diesel buses with electric buses on regional WA school bus routes. It also offered economic modelling and investigated eleven towns as detailed case studies. The study conducted a market analysis for electric school buses, charging stations, and stationary battery storage options and analysed the following:

• The availability and cost of electric buses that are suitable for regional school bus operations
• The minimum sizes and availability of appropriate electric school bus charging stations
• The electricity network’s capacity to supply the power needed for small and large depots
• The electric school bus charging load and how it impacts peak electricity demand and power quality, and
• The advantages of reductions in diesel use and greenhouse gas emissions.

The global context

Sales of new electric buses are dominating some global markets, including Europe, North America, China, and India. These countries comprise more than 90% of the world’s EV fleet, most being government owned and in urban areas.

Six out of 10 buses sold are predicted to be EVs by 2030 due to increasing numbers of national governments globally pledging zero-emission vehicle targets by 2040.¹

Major reasons for investing in electric buses includes improving urban air quality, reducing oil consumption, industrial development opportunities, and to decarbonise the transport sector. Globally, heavy road vehicles such as buses and trucks account for 35% of direct GHG emissions from road transport. However, they represent less than one in 12 vehicles.²

The Australian context

Australia is slowly increasing adoption of EVs, mostly passenger cars. Adoption of electric heavy vehicles is very low, although state governments have committed to transitioning urban bus fleets to battery EVs. The Australian approach has been small pilot programs, which tend to focus on metropolitan areas.

For example, the Queensland government has committed all new TransLink-funded buses to be environmentally friendly from 2025. The NSW government is transitioning its 8,000+ diesel and natural gas public transport buses to zero emissions technology. Victoria will add 36 zero-emissions buses to its public bus fleet over the next three years. South Australia is trialling hydrogen fuel-cell electric buses. In Tasmania, the government is trialling battery-electric and hydrogen fuel-cell buses. The ACT has 16 electric buses and will add 90 over the next three years.

WA started with a trial of electric buses in the Joondalup CAT network in early 2022; and, in January 2024, a timeline for the transition of the Transperth bus fleet was released, initially with 130 new locally-built electric buses. Currently, the Public Transport Authority of WA manages a comprehensive network of regional school bus services, with independent contractors operating 935 diesel-powered buses.

Each of the 935 school buses have a 17-year contract, with an average of 55 buses replaced annually. This research showed that there is now no economic or technical barrier to the transition to a 100% electric school bus fleet in WA. A new diesel bus contracted today will be in service until 2041.

Electric bus charging scenarios

The study also researched the availability of electric buses and EV charging equipment. This included analysing where and when the buses would need to be charged and the primary source of the electrical energy in use over time.

Researchers analysed the energy demand of the electric buses for the trip from the depot to and from the school once daily (ie an option of leaving the bus during school hours to recharge), or twice daily (recharging at the school or other locations). The study found that 77% of buses could directly charge from the electrical grid at their depot site. This could occur even for slow charging, using inexpensive three-phase AC chargers, which are simple to install and replace. Meanwhile, high-powered DC chargers and larger batteries on some buses would suit areas with higher operating demands.

The remaining 23% of depot sites that lacked enough on-site power at the depot for e-bus charging were able to access sufficient power for charging at a school. Schools often have excellent electricity grid connections in rural and regional areas. Almost all schools within the case studies were able to install at least one 50 kW fast charger without upgrading the grid. Many towns had more than one suitable school.

A very small number of the WA sites – schools or depots – would need extra measures such as:

• Grid charging, supplemented by a stationary battery
• Added energy through a grid upgrade
• Added energy through renewables and a generator

WA’s current bus fleet

The WA State Government aims to reduce emissions from the public sector by 80% by 2030. The State’s public transport authority currently:

• Operates 935 diesel school buses from 544 locations with one to 41 buses per site
• Services 429 schools
• Travels 31.7 million kilometres via school buses a year, using 7.5 million litres of diesel and 370,000 litres of AdBlue annually
• Emits 20,000 tonnes of GHGs

Market analysis: Electric buses

Globally, the electric bus market is dominated by electric low-floor metro city buses. Many of these are high-end inter-city and long-range luxury tourist coaches and are unsuitable for use as school buses in regional WA. Meeting the requirements of the Australian Design Rules, or availability of right-hand drive models limits suitability for the WA school bus service.

The relatively small size of the Australian electric bus market makes it difficult for overseas manufacturers to find or establish local distributors to provide the necessary aftersales and warranty service.

Due to those various limiting factors, the number of electric bus models of all classes currently available in Australia that would be suitable for use as school buses in regional Western Australia at the time this report was produced was just 19, comprising two to five models in each of the A, B, C and D classes, but no models in the 4×4 classes.

However, it should be noted that the number of suitable, available models did increase over the course of this study, and that situation is likely to improve further in the future. The researchers noted that 4×4 bus classes in WA are often ‘custom-builds’ from 2×4 diesel classes, so this is unlikely to be an issue.

E-bus vs diesel comparative analysis

The researchers developed a detailed case study for the town of Denmark in WA comparing electric and diesel buses, finding no subsidies were needed for EV charging technology investments to meet zero-emission targets cost-effectively. Because electric energy is domestically produced, it’s relatively stable as an energy supply, therefore buffering the state’s transport fleet to geopolitical, market volatility, or supply chain issues in the global oil market.

These findings enabled the report authors to include another 10 towns into case studies to quantify actual bus route energy consumption per bus type, and the associated costs of a diesel vs electric fleet equivalent. For all case studies undertaken for numerous buses in multiple towns in every major WA regional area, there were no significant economic or technical barriers to e-bus adoption over the contract lifetime.

Servicing and training

EVs have fewer mechanical components, so need less frequent servicing than diesel equivalent vehicle types. The existing mechanical workforce can service many components of an e-bus, but technicians and components must be ‘flown in’ for the more specialised tasks. While WA lacks mandatory licensing for servicing EVs, this is expected to change. Technical areas covered include:

• High voltage;
• Using advanced diagnostic tools and software;
• Technical precision due to the intricacy and sensitivity of EV components, and
• The mechanical simplicity of EVs.

As EV demand increases, so will the need for qualified specialist technicians.

Alternative Zero-Emission School Transport

Hydrogen fuel cell buses offer another option for zero-emission school transport. The significant technical and economic hurdles complexities of hydrogen infrastructure makes hydrogen-based road transport more expensive than fossil fuels and will unlikely play a role into the future.

Hydrogen vehicles are several times more expensive than the equivalent EVs that exhibit greater technical and economic advantages. While the study included analysis of some alternatives to battery electric vehicles, the dominance of electrification for zero-emission bus transport makes it the only practical alternative to a diesel bus.

Case studies

To determine the feasibility of an electric school bus fleet in WA, the project examined case studies across 11 towns comprising 24 bus depot sites:

• Denmark (Great Southern)
• Walpole (South West)
• South Hedland (Pilbara)
• East Carnarvon (Pilbara)
• Esperance (Goldfields-Esperance)
• Manjimup (South West)
• Green Head (Mid West)
• Morawa (Mid West)
• Fitzroy Crossing (Kimberley)
• Northam (Wheatbelt)
• Narrogin (Wheatbelt).

All towns had suitable sites for each scenario for bus charging needs for all buses servicing all schools. No technical barrier precluded the transition to electric buses for the entire fleet. This assessment was based on having sufficient power at the depot or serviced schools. Western Power’s initial data indicates rural schools are highly likely to have sufficient existing power capacity to support electric bus rapid charging. The very few sites needing alternative arrangements would require small custom solutions with existing technology.

The study developed a detailed economic model to quantify the estimated a 17-year contracts of all electric bus route contracts in service within the 11 towns. The economic modelling showed that there was little difference in the total cost of the bus contract when comparing electric buses to diesel buses for the same period. The economic uncertainties to both the government and private contract holders were reduced with electricity prices relatively stable relative to diesel fuel and AdBlue prices.

The researchers suggested options to fund the transition in terms of charging infrastructure. As demand for electric energy and both passenger and bus EV charging stations are expected to grow across WA, a short-to-medium term option would involve highly cost-effective investments in school-based EV rapid EV charging capabilities in regional and remote areas. This was because schools are a major destination in these regions often located on major transport corridors, and there are often no prohibitively expensive electrical grid upgrades required at schools. Schools (and some other large community buildings such as recreation centres) often have spare electrical capacity and parking space to host rapid DC fast charging facilities.

Finally, schools have some very large roof-space suitable for lowest cost PV systems, schools can achieve lower cost renewable electricity due to the excellent technical match between daytime electric bus charging and the high PV production. Rapid EV chargers can also have long underground cables from the school electrical connection to be located off-school site as a solution for public rapid EV charging services. The present cost of rapid DC charging services (per kWh) is significantly higher than the kWh cost from electricity retailers or on-site PV electricity production. The high margins can easily recoup the investment either a school or other investor has made with a popular charging location.

School e-bus would be prioritised for charging on school days. As weekend and school holiday electric school bus demand is negligible, this matches the peak tourism periods where rapid EV charging demand is often highest in WA’s regional and remote towns. These arrangements (including stationary batteries in regional areas or future V2G capabilities) could enable very low GHG emissions and minimum cost while supporting the electrical network, particularly during blackouts or evacuations due to natural disasters/bushfires.

School Bus Operator Survey

Researchers conducted an online survey of school bus operators and followed up with a question-and-answer session. Views were gathered on awareness levels, interest in trials, details about their current fleets, garage locations, power infrastructure, and the possible technical challenges in the move to electric buses. School bus operators were largely unaware of the technical developments and advances of both electric buses and the associated charging infrastructure required, and most questions were related to:

• Availability of servicing and charging infrastructure in regional areas;
• Range;
• Upfront and ongoing costs, and
• The reliability and durability.

However, during the question-and-answer session, most questions had relatively straightforward technical answers. Operators showed significant interest in more details, specific e-bus model performance data, and sought involvement in any future trials. Operators saw the opportunity of reducing the high uncertainty of diesel fuel, AdBlue, and high maintenance costs of their diesel buses. Operators with a familiarity with to the benefits of passenger EVs were cautiously optimistic about the implications this may have for their bus operations – if the contractual arrangements allowed it.

Summary findings

Top-level findings in this research include:

• The introduction of electric school buses and corresponding charging stations is technically feasible, economically viable for all case studies investigated.
• 73% of all 544 school bus depots (with 64% of all 935 school buses) can supply electricity sufficient to charge onsite without a grid upgrade.
• For many of the sites with insufficient grid capacity, charging will be possible at the corresponding schools. Only a very small percentage of sites require either a grid upgrade or local generation.
• E-bus emissions are expected to reduce to just 3,000 tons of CO2 -e by 2030 (85% less than diesel) due to WA’s emission reduction target for the grid.
• Making e-bus chargers available to the public (residents and tourists) on weekends and school holidays will generate substantial income.

Significantly, the report’s detailed analysis points to the following conclusion:

… there is no economic or technical barrier to transition to a 100% electric school bus fleet in WA.

Expected project impacts

The PATREC (UWA) research team has undertaken a comprehensive assessment of the technical feasibility of electric buses for regional school bus operations and the associated benefits. The depth of assessment and key findings are important building blocks to inform advice to the State Government on when this transition from diesel to electric buses could occur.

It has also raised a number of implications for the contract model between the Public Transport Authority and bus contractors that would need to be considered and dealt with before this transition could commence.

Steve Beyer, Director, Transport Portfolio Sustainability and Strategic Projects, WA Department of Transport

Footnotes

1. International Energy Agency (2023).Trends in electric heavy-duty vehicles. Global EV Outlook
2. In developing countries, the e-mobility revolution is closer than you might think