By Todd Mouw
In 2023, St. Louis County Schools’ robotics team attended an out-of-state competition. The team successfully traveled 1,200 miles roundtrip from their hometown of Babbit, Minnesota, to Peoria, Illinois, on a propane school bus pulling an enclosed trailer.
While many school districts operating propane school buses report reserving diesel buses for long-haul field trips, Kay Cornelius, transportation director for the district, was certain that the district’s propane buses could get the job done.
With confidence in the alternatively fueled bus, Cornelius plotted out fueling stops along the robotic team’s journey ultimately fueling twice on the way to Illinois and twice on the way home. She also ensured that the driver was sufficiently trained to operate the propane bus during the extended trip. “I had never driven a propane bus before this trip and was unsure about it all,” said the driver. “The district helped me by bringing in a seasoned propane [school] bus driver to train me on the system. I really loved the experience of driving the propane bus. I prefer driving propane buses now.”
For nearly a decade, the repairs and maintenance budget for St. Louis County Schools in Minnesota remained unchanged — despite a growing student population and several school expansions. “I credit having propane buses with keeping our dollar amount low for 10 years,” said Cornelius.
School Buses and Alternative Fuels
When it came to researching alternatives to diesel buses, Cornelius 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 added. After consulting further with the local school bus dealer, United Truck Body, and propane supplier, Como Oil & Propane, Cornelius was set on propane school buses.
During the initial research, Cornelius also learned that maintenance on a propane school bus is significantly less than diesel. That has proven to be true. 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. Across the nation, 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.
In addition to the bottom-line savings, the district finds that its Blue Bird Vision Propane school buses equipped with ROUSH CleanTech propane fuel technology have a cleaner engine area and fewer emission issues than its diesel models. When compared with gasoline or diesel vehicles, school buses that run on propane autogas emit fewer greenhouse gases and 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 diesel buses. And, the drivers appreciate that they don’t have the dirty diesel exhaust, improving the air quality for them and students alike.
The Switch to Propane
Another reason for the move to propane was the tightened standards on diesel emissions which forced burdensome requirements on the district. 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,” Cornelius said. “In my opinion, when they started upgrading the emissions, they created some very expensive issues. 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.”
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. “With propane buses, there are less items to watch for and they are much cleaner to work on,” Cornelius said.
The district currently runs nearly 95% of its bus fleet on propane, only using diesel buses for backup. After a successful decade of propane autogas deployment, Cornelius established the district’s ‘propane rolls first’ protocol. “Our staff know that, unless a propane bus is being worked on and cannot be driven for the day, the propane buses get used first,” she said. “If a driver starts up a diesel bus, they need to explain why.”
When it comes to the future operational and financial health of the St. Louis County Schools transportation department, Cornelius is confident that propane is the best choice. “Planning ahead and planning well will give you success,” she said. “Propane is the right plan for us.” And, the thousand-mile field trip is proof positive that the plan is working.
Todd Mouw is executive vice president for ROUSH CleanTech, an industry leader of alternative fuel vehicle technology. Mouw has served as president of NTEA’s Green Truck Association and is currently a Board member for NTEA. To learn more, call 800.59.ROUSH or visit ROUSHcleantech.com.