From Yellow to Green: Considerations to Electrify School Bus Fleets in Ontario 

Electrifying school bus fleets seems like the obvious solution to a couple of problems – namely, reducing pollution and protecting the health of children by removing harmful pollutants from their daily routines. However, it’s not as simple as it seems. In this article, Neetu Garcha explains how we can address some of the barriers to electric school bus fleets, including charging infrastructure concerns, the need to re-train bus drivers, and the initial cost of purchasing a new fleet of buses.

Each morning, over 50,000 school buses pick up millions of children. The vast majority of these buses run on diesel—a technology with consequences beyond the tailpipe. Electrifying school bus fleets presents a rare opportunity to tackle multiple priorities at once: reduce greenhouse gas emissions, eliminate harmful air pollution for children, and lower fleet operating costs over the long term. 

But their rollout is anything but simple. Transitioning an entire fleet is not just a matter of swapping vehicles. It requires new infrastructure, operational planning, training, and financing strategies—often undertaken by fleet operators who are small businesses or municipal departments with limited capacity for risk or experimentation. 

Why Focus on School Buses? 

The case for electrifying school buses is strong. In Ontario alone, there are more than 18,000 school buses emitting over 250,000 tonnes of CO₂ annually. Diesel exhaust has been classified as a human carcinogen by the World Health Organization and is particularly harmful to developing lungs. Children riding on diesel buses are exposed to elevated levels of nitrogen oxides and particulate matter. Electrifying school buses eliminates tailpipe emissions entirely, reducing localized air pollution in school zones and residential neighborhoods. 

Financially, electric buses offer lower fuel and maintenance costs over their lifetimes. Yet high upfront capital costs, site electrification needs, and utility interconnection requirements often create insurmountable hurdles—particularly for the small- to medium-sized private contractors that operate many school buses in Canada. 

Starting with the Right Questions 

School bus electrification projects that succeed typically start by asking the right foundational questions: 

• How much electrical capacity is available at the depot, and is it sufficient for the charging needs of electric buses? 

• How will peak demand charges affect operating costs? 

• What charging strategy will ensure buses are ready when needed, especially in winter? 

• What grant or incentive programs can help offset capital costs? 

• What additional training is needed for drivers and maintenance staff? 

The answers to these questions vary by site—but failing to ask them early often leads to cost overruns, timeline delays, or underutilized assets. 

Considerations: What Won’t Work 

1. Infrastructure Isn’t Just About Chargers—it’s About Grid Capacity 

Distribution grid upgrades—not the vehicles themselves—are often the largest cost component in fleet electrification. For school buses, which primarily use Level 2 charging at depot sites, the costs are generally moderate—but still significant when multiple chargers are installed in parallel. 

Site assessments must evaluate both behind-the-meter electrical capacity (e.g., panel upgrades, conduit runs) and upstream utility capacity. Substation upgrades, which can cost over $10 million and take years to complete, may be triggered if aggregate load exceeds thresholds—even unintentionally.

Best Practice: Engage the utility early and request load capacity evaluations for your depot. Where possible, stagger deployments to avoid peak infrastructure costs.

2. The Cheapest Charger Isn’t Always the Most Cost-Effective 

Many fleet operators are unfamiliar with the nuances of Level 2 vs. Level 3 charging, smart charging capabilities, or charger compatibility. In some fleet electrification cases, opting for slower chargers can actually improve project economics. In Hydro-Québec’s fleet electrification demonstration project, a trial with Class 6–8 trucks, a 50 kW charger was sufficient to recharge vehicles overnight—yet many operators initially assumed they needed 150 kW units. This resulted in higher demand charges and unnecessary capital costs. 

For school buses that operate on single daytime shifts and return to base by late afternoon, charging windows are often long enough that 19.2 kW Level 2 chargers are sufficient. Upgrading to higher-powered DCFC may only make sense for larger fleets where vehicle turnaround time is tight. 

Best Practice: Match charger power to duty cycle, not just vehicle capability. Lower-powered chargers reduce both installation and electricity costs—without sacrificing performance. 

3. Site Planning Timelines Are Longer Than Most Expect 

Fleet operators often underestimate how long it takes to get chargers in the ground. One of the most common roadblocks is assuming chargers can be installed as soon as the buses arrive. In reality, utility connection upgrades, permitting, and civil work can take many months—longer than the procurement of the vehicles themselves in some cases. From electrical design and permitting to trenching and commissioning, a single depot upgrade can take 9–12 months or longer. If grid upgrades are required, timelines can easily extend to 18–24 months. 

In most provinces, utility investment is reactive by regulation—meaning utilities can’t expand capacity unless a formal customer request is made. This leads to long delays and coordination issues between utilities, municipalities, and private operators. 

Best Practice: Start infrastructure planning before vehicle procurement. Building the chargers must be treated as a parallel—not sequential—process. 

What’s Working: Models of Success 

Despite the hurdles, many early adopters are making it work. Successful ESB projects often share a few common traits: 

• Cross-Functional Collaboration: Successful projects bring together transportation managers, facility staff, utility representatives, electrical contractors, and fleet planners early in the process. This integrated approach helps identify risks and opportunities others may miss. 

• Phased Deployment: Instead of trying to electrify an entire fleet at once, starting with a small pilot—say, 2–5 buses—allows operators to test schedules, charging strategies, and driver feedback before scaling up. These early learnings de-risk future phases. 

• Smart Charging Solutions: Managing when and how buses are charged is critical to controlling electricity costs and ensuring vehicles are ready for duty. Smart charging systems can automate this process based on schedules, utility rates, and available power capacity. 

• Training and Buy-In: Drivers and maintenance teams are often skeptical of new technology—until they experience it. Training programs that offer hands-on experience with ESBs, dispel myths (especially around winter performance), and address operational concerns help build buy-in and confidence. 

• Financial Planning: Total cost of ownership modeling, including grants, incentives, fuel savings, and maintenance, helps fleets understand the long-term benefits—even when upfront costs appear daunting. 

Policy Needs: Accelerating What Works 

Market enthusiasm alone won’t scale electric school buses quickly enough. Governments at all levels have a clear role to play in accelerating adoption. This includes: 

• Grid Capacity Planning: Provinces should enable utilities to proactively plan and invest in grid upgrades aligned with electrification goals—rather than waiting for customer triggers. 

• Streamlined Permitting: Municipalities and provinces should harmonize permitting processes to speed up charger deployment. 

• Technical assistance programs to provide advisory support, especially for smaller operators. 

• Fleet Transition Funds: Programs like Canada’s ZETF (Zero Emission Transit Fund) are a start, but dedicated funding for depot upgrades and advisory services is needed—especially for independent contractors and school boards. 

• Procurement Aggregation: Bundling demand through joint procurement can reduce vehicle and charger costs while standardizing technical specifications. 

Looking Ahead: A Scalable Climate and Public Health Win 

Electrifying school buses is one of the clearest win-wins in climate and public health policy. Electrifying these fleets protects children’s health, reduces climate impacts, and builds the infrastructure foundation for broader fleet transitions. 

But it’s not a plug-and-play transition. Real progress requires planning, coordination, and support from many moving parts: utilities, contractors, regulators, and funders. By learning from early deployments, investing in infrastructure, and aligning policy with operational realities, we can unlock the full potential of the yellow school bus to drive a cleaner, healthier future.