ARGONNE, Ill. — A new case study from the U.S. Department of Energy's (DOE) Argonne National Laboratory examines five school districts that are successfully using propane in their school bus fleets, with some of the districts saving nearly 50% on a cost-per-mile basis for fuel and maintenance relative to diesel.

The districts also saw a variety of other environmental and social benefits, officials said.

The case study describes both the benefits and challenges of deploying propane in school bus fleets. Using Argonne National Laboratory’s Alternative Fuel Life-Cycle Environmental and Economic Transportation (AFLEET) Tool developed for the DOE’s Clean Cities program, the results showed payback periods over which the fleet recouped the incremental costs of vehicles and infrastructure ranging from three to eight years.

Overall, fuel economy for these propane vehicles is close to that of the diesel vehicles they replaced, on an energy-equivalent basis. In addition, the 110 propane buses described in the study eliminated the use of 212,000 diesel gallon equivalents per year of petroleum, and 770 tons per year of greenhouse gases.

The study is available for download from the Alternative Fuels Data Center website.

DOE’s Clean Cities program supported the development of the case study and AFLEET tool. Clean Cities works with a network of nearly 100 coalitions to advance the nation’s economic, environmental and energy security by supporting local actions that reduce transportation-sector petroleum consumption. Clean Cities is an initiative of DOE’s Office of Energy Efficiency and Renewable Energy.

For more information about the study or the AFLEET tool, contact Andrew Burnham at