Measuring the Impacts of Electric School Buses

Measuring the Impacts of Electric School Buses

by  Dave Seamonds, Director of Program Management, Highland

Greenhouse gas (GHG) reduction is a key benefit for communities incorporating electric school buses. By measuring the reduction of emissions like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), which are all potent greenhouse gasses, we are able to quantify the real impacts of going electric.

How Do We Measure Carbon Emissions?

Emissions calculations involve quantifying the amount of CO2 emissions that are being released into the air from diesel or gasoline school buses. This analysis can be done in several ways:

1. Using emissions monitoring equipment. 
   • By using a portable emissions monitoring system – which is typically attached to a diesel or gasoline vehicle and measures the pollutants contained within the exhaust stream as the vehicle operates – data is collected and carbon emission intensity is calculated.
2. Measuring the carbon content of the fuels in your vehicle(s).
   • A bus’ fuel tank can be sampled and the resulting sample provided to a certified laboratory. The lab can then perform specific tests on the fuel, including the ASTM D5291 test method, which determines the total carbon embedded within the fuel. Using the determined carbon content, along with the vehicle’s assumed efficiency (miles-per-gallon) and annual mileage driven, the carbon emissions can be determined.
3. Using an emissions calculator. 
   • This is a simple tool that allows individuals and/or organizations to estimate their emissions quickly based on the needs and activity of their fleet using standard assumptions. Calculators typically include multiple emission species, including GHGs as well as criteria air pollutants.
   • Use Highland’s new Emissions Calculator to visualize the impact of upgrading your school district’s fleet to an electric fleet.

How Do We Calculate Emission Reductions?

• To calculate emission reductions, we compare the emissions from the “baseline” vehicle (i.e., diesel or gasoline school bus) to the emissions associated with electric school bus charging for the equivalent distance driven. Electricity is typically produced using regional power generating stations, which can be fueled using petroleum fuels or more sustainable technologies such as wind turbines, hydroelectric power or solar arrays. When electricity is produced using sustainable sources, significant emission savings can be realized. Taking this one step further, electric school buses will continue to become even cleaner as power generation in the US continues to embrace sustainable and renewable technologies.As an example calculation, if a diesel school bus emits 5 metric tons of CO2 emissions, and an equivalent electric school bus only requires 1 metric ton of CO2 to charge the vehicle, comparatively, the electric school bus will reduce 4 metric tons of CO2 emissions.

How Do Electric School Buses Reduce Carbon Emissions?

According to NYSBCA, one school bus replaces an average of 36 cars on the road. As a larger type of EV, electric school buses help to lower carbon emissions more than passenger vehicles in two ways:

1. Unlike diesel school buses, electric school buses are battery-based and do not combust fuels, nor have a tailpipe – meaning they inherently negate the possibility of carbon being released into the atmosphere at the point of use.
2. Fuel production emissions are significantly lower when comparing electricity to petroleum fuels, such as synthesizing gasoline or diesel fuel. Electricity power generation has been rapidly decarbonizing as technologies such as wind and solar become more prevalent, while fossil fuel production has only seen modest carbon reductions related to producing transportation fuels.

What Are the Accompanying Benefits of Electric School Buses?

There are many benefits to communities who use electric school buses. One of the most important benefits is that EVs support improved air quality for everyone. 

By reducing pollutants in the air, electric school buses improve air quality, which has significant health benefits for children as well as bus drivers and the local community. Having access to cleaner air has been proven to reduce respiratory issues such as asthma and can also result in reduced student absenteeism.

Embracing electric school buses and other carbon reduction methods is a vital step toward creating healthier, more sustainable communities. By understanding how to measure emissions and the benefits of electric buses, you can make an informed decision that contributes to a cleaner and greener future.

Try our brand-new Emissions Calculator to measure the impacts of an electric fleet in your community.