On any given school day, more than 26 million children ride to and from school on one of the 500,000 school buses in the USA. On average, a student bus rider is on the bus for 48 minutes each day. With the wait time to enter and exit the bus, the time a student is near or on a school bus is well over an hour. During this hour every school day, a bus rider is exposed to dangerous exhaust and noise pollution.
Diesel engines have historically been a source of large amounts of greenhouse gases, particulate matter, and dangerous airborne chemicals. Emissions from diesel school buses have been linked to respiratory disease, asthma and even cancer. While knowing the effects of diesel emissions is one thing, recent studies have shown that a decrease in diesel emissions has led to increased academic performance and health benefits.
As the popularity of electric vehicles (EV) grows, an awareness of the need for electric school buses (ESB) is important. Currently, there are just over 1,800 new ESBs that have been purchased or committed. However, that is less than 0.5% of the total number of diesel school buses in America.
One problem with electrifying the nation’s fleet of school buses is the prohibitive cost. On average, the cost of a new fully electric school bus is three to four times the cost of a new diesel bus. While there are significant cost savings with lower fuel costs and minimal maintenance, the initial purchase price is preventing many school districts and fleet owners from making the switch to electric. Adding in the cost of setting up charging infrastructure makes the total cost even less affordable. There are many grants and a growing amount of federal funds earmarked directly towards ESBs, but it is not nearly enough for the entire fleet of school buses in the USA.
Another problem is supply. Around 40,000 new school buses are sold each year. Of those, only a small fraction is electric. Even if every new school bus sold is electric, it would take over 12 years to replace the entire fleet of 480,000 buses.
Replacing current diesel school buses with new ESBs causes another problem. The diesel bus that was replaced is then resold and continues to operate, emitting harmful greenhouse gases, particulates, and carcinogens. Just replacing the bus doesn’t reduce the total amount of emissions if the existing bus remains in service within some other fleet.
Retrofitting existing school buses helps solve these three problems simultaneously.
On average, a new electric school bus costs $300,000-400,000.
Retrofitting an existing school bus to fully electric only costs $50,000-100,000, depending on size, range and specifications.
For the same amount of funds, 3-4 times as many electric school buses can be added to a fleet when compared to new buses.
Producing a new electric school bus is capital-intensive and requires a lot of time to build from the ground up.
On the other hand, retrofitting an existing bus simply replaces all of the internal combustion engine components, such as the engine, gas tank, catalytic converter, and replaces them with an electric motor, batteries and controller. This is done without any modification of the frame, structure, or body of the bus, so this process is much faster than a new build and there are no reductions in safety.
Buying a new ESB still leaves a diesel bus in the system. Often, it is placed in a different fleet and continues to burn diesel and emit harmful chemicals.
Retrofitting a school bus is recycling the current resource. The diesel-burning bus is taken completely off the road and is converted to an electric bus that has zero-exhaust emissions.
Electrifying this country’s school buses is a necessary step to reduce greenhouse gases fast and to improve the health of school children. Retrofitting existing school bus fleets helps achieve this goal faster, for less of an investment, and with significantly less waste.