Alvin Independent School District Case Study Alvin Independent School District Case Study
Alvin Independent School District — Alvin, TX
CHALLENGE & SOLUTION
Following the energy crisis of the 1970s, Alvin ISD converted its school buses to propane autogas to overcome supply shortages and price spikes with gasoline. Thirty-one years later, the district transports 8,000 + students daily and reports reduced maintenance, improved performance, and substantial cost savings.
- School district saves 50 percent on fuel costs annually compared with conventional fuels.
- High-volume propane autogas infrastructure cuts refueling time in half.
- Propane-autogas-powered buses reduce maintenance, downtime and meet Texas Commission on Environmental Quality Clean School Bus Program requirements.
Alvin ISD, a Texas school district just south of Houston, converted its school bus fleet to propane autogas following the energy crisis of the 1970s. Fuel access and pricing was starting to hinder the district’s transportation department, and, after researching alternative fuels, the district switched to propane autogas in 1982. Thirty-one years later, Alvin ISD operates more than 100 propane autogas school buses that travel nearly one million miles each year combined.
ADVANCED TECHNOLOGY INCREASES EFFICIENCY
Today, more than half of Alvin ISD’s buses run on propane autogas, including 70 dedicated propane Blue Bird Vision Type C buses and 36 converted gasoline buses. The remaining fleet is made up of 80 diesel-fueled buses. According to Juan Mejias, Alvin ISD’s fleet maintenance manager, drivers have developed a preference for the propane autogas buses, and the district relies on them for their power and ease in maintenance.
“Our bus drivers love the acceleration with propane autogas,” Mejias said. “When we take the buses out of rotation for routine maintenance and drivers use the spare diesel buses, they come back and ask us how soon they can get their propane bus back. The drivers don’t have the same hesitation accelerating and merging in traffic like they do with the diesel buses. The performance is that good.”
After three decades with propane autogas, the district has witnessed noticeable improvements in engine technology over the years. New Blue Bird Vision buses are equipped with clean-burning Roush CleanTech liquid propane autogas fuel systems, and Mejias reports they are simpler and easier to service.
“The overall cost and maintenance is the best,” Mejias said. “It’s very easy for me to get a mechanic over and get work done in a very short period of time on our propane-autogas-powered buses. With our diesel buses, there are additional filters to change and more components to look at.” Mejias explained that with diesel, the buses have particulate filter and exhaust gas recirculation (EGR) systems that require continual upkeep.
HIGH PERFORMANCE, LOW MAINTENANCE
On average, Alvin ISD retires its buses every 13 to 14 years, with each propane autogas bus running approximately 270,000 to 280,000 miles during its lifetime. When maintenance costs such as routine oil changes are calculated over the lifetime of the bus, savings with propane autogas versus conventional fuels compounds quickly.
“We’ve experienced extended oil changes to every 10,000 miles with propane compared with 6,000 or 7,000 miles with diesel,” Mejias said. “That’s a big savings over time.”
Savings in maintenance and oil changes alone can add up quickly with a large bus fleet like Alvin ISD’s. When the district adds its lower fuel cost into the calculation, Alvin ISD easily doubles its total savings with propane autogas.
“We’ve been using propane autogas for decades, and we have always seen substantial cost savings, even without the federal credit,” Mejias said.
In a head-to-head comparison between 56 of the district’s propane autogas buses and 56 diesel buses, propane autogas cost the district 37-cents less per mile to operate than the diesel-fueled buses before the 50-cent tax credit. Additionally, the fleet of propane-autogas-powered buses traveled nearly 500,000 more miles than the diesel buses for the same fuel cost.
HIGH-POWER PUMPS REDUCE REFUELING TIME
Propane autogas provides an affordable infrastructure solution for school bus fleets using a central refueling station. For Alvin ISD, new propane autogas infrastructure has saved the district both time and money.
The district recently used an $80,000 grant to upgrade to a higher volume pump and dispenser to service its growing propane autogas bus fleet. Alvin ISD currently operates an 18,000-gallon tank with three dual dispensers, allowing them to fuel six buses at the same time.
“The new pumps allowed us to refuel more buses at once and practically cut refueling time in half,” Mejias said. Additionally, Mejias credits the service of their propane retailers with providing reliable 24/7 service for the district, eliminating supply issues of previous decades.
“They [propane retailers] go out of their way to make sure they deliver our fuel on time,” Mejias said. “Even if it’s at midnight or four in the morning — they’ll make sure we have the fuel we need to get the job done.”
CLEAN, GREEN FUEL
While Alvin ISD has seen many long-term financial benefits of fueling with propane autogas, the district’s alternative fuel buses also help it meet environmental standards in the state. Propane autogas buses burn cleaner than conventional fuels and are exempt from state idling restrictions and emissions testing. Alvin ISD’s fleet also meets all Texas Clean School Bus Program requirements set by the Texas Commission on Environmental Quality (TCEQ).
In 2012, the World Health Organization classified diesel exhaust from buses manufactured prior to 2007 as a carcinogen that can have long-term health effects, especially on children. Propane-autogas-powered buses also emit 11 percent fewer greenhouse gas emissions than gasoline.
“To me, it’s a no brainer to use propane autogas,” Mejias explained. “The new [propane autogas] buses have the perfect engine and performance. Propane [autogas] runs cleaner, it’s low maintenance — it’s the perfect fuel to use for a school bus.”