For nearly a decade, the repairs and maintenance budget for St. Louis County Schools in Minnesota has remained unchanged – despite a growing student population and several school expansions. The district currently serves about 2,250 students.
“I credit having propane buses with keeping our dollar amount low for 10 years,” says Kay Cornelius, transportation director for the district.
In addition to the bottom-line savings in the cost of maintenance and cost-per-mile to operate, the district has found that its 29 Blue Bird Vision Propane school buses have a cleaner engine area and less emission issues than its diesel models. This cuts the district’s compliance requirements, which leads to reduced operational costs.
Right now, there are more than 22,000 propane autogas school buses driving more than 1.3 million students each school day in the U.S. Hundreds of school districts have reported savings of up to $3,700 per bus per year due to lower fuel and maintenance costs compared with diesel.
That money could go back into the classroom. According to the World LP Gas Association, if all the nation’s diesel school buses were converted to propane, U.S. school districts could hire more than 23,000 teachers with the fuel and maintenance savings.
Budget success with fuel and funding
Cornelius performed due diligence when it came to researching alternatives to diesel buses.
“I was looking for ways to save money. With grants and fuel rebates that were available, there was an incentive for us to take the leap to alternative fuel,” she says.
After consulting further with the local school bus dealer, United Truck Body, and propane supplier, Como Oil & Propane, Cornelius was set on propane.
Como Oil & Propane installed an on-site propane station.
“We paid for the electrical for the pump and they did the rest,” Cornelius remarks.
The district is also more insulated from fluctuating gas prices, allowing them to better forecast their budget. The district’s current price per gallon of propane is $1.52 compared with $5 per gallon of diesel – a 70% savings on the cost of the fuel alone.
“We are able to negotiate on a yearly basis the price per gallon,” she notes.
Last year, the propane buses used approximately 70,000 gallons of propane, resulting in a savings of nearly $240,000 for the school district.
During the research phase, Cornelius also learned that maintenance on a propane bus is significantly less than diesel. Currently, the school district saves nearly 50% per oil change. For a diesel bus, an oil change costs the district about $400 compared with about $200 for a propane bus.
With the signing of the recent Bipartisan Infrastructure Law, more federal funding is available to school districts looking to transition to emissions- and cost-reducing propane school buses. The Environmental Protection Agency is providing $5 billion over the next five years to replace existing school buses with zero-emission and low-emission models. The rebate program for 2022 is currently open and accepting applications.
Cleaner, easier operations
Tightened standards on diesel emissions forced burdensome requirements on St. Louis County Schools. Operating on propane autogas instead of diesel removes the complexity and cost of after-treatment measures, which can accelerate return on investment and cut operating costs.
“I found that we have a lot more mechanical issues with the diesels. In my opinion, when they started upgrading the emissions, they created some very expensive issues,” Cornelius says. “We’re finding that there are high-pressure oil rail issues, and that the engine is burning so hot that the oil will actually take on the consistency of coffee grounds. So, we have to do oil changes at shorter intervals. Diesel emission fluid has created a whole new problem, as we’ve had to deal with dosing problems and freezing issues.”
An oil change for one of St. Louis County Schools buses uses about seven quarts compared with 25 to 30 quarts for a typical diesel engine.
“With propane buses, there are less items to watch for and they are much cleaner to work on,” Cornelius says.
Additionally, with propane, there is no need for diesel particulate filters, diesel exhaust fluids, exhaust gas recirculation or other after-treatment devices. That’s more than 15 parts that aren’t needed for the school district’s propane buses.
New technology, positive feedback
Cornelius observes that Ford’s new 7.3-liter V8 engine with the ROUSH CleanTech Gen 5 propane fuel system has more power than her diesel buses, among other benefits for drivers and students.
“In comparing it to a diesel, the engine is much quieter, and the clean burn of the propane is a plus for drivers because the exhaust is nearly odorless,” she adds.
When compared with gasoline or diesel vehicles, school buses that run on propane autogas emit fewer greenhouse gases, smog-producing hydrocarbons, and virtually eliminate particulate emissions.
In addition, St. Louis County Schools’ bus drivers report that the propane buses are much quieter, as propane buses reduce noise levels by about half compared to a diesel engine. And, the drivers appreciate that they don’t have the dirty diesel exhaust, improving the air quality for them and students alike.
Currently, the district runs about half of its bus fleet on propane and will continue to replace aging diesel buses with propane, according to Cornelius.
Todd Mouw is executive vice president of sales and marketing for alternative fuel vehicle technology specialist ROUSH CleanTech.
