TAMPA BAY, Fla. — Local school districts have added more than 170 new propane-powered school buses to their fleets, and have seen lower emissions and savings in fuel and maintenance costs.

Since 2015, Pinellas, Polk, Pasco, and Hillsborough County school districts have added propane-fueled buses to their fleets. All the buses are manufactured by Blue Bird and equipped with ROUSH CleanTech propane autogas fuel system technology.

“We did our research. In comparison to the capital outlay and system requirements for other options, propane was by far the easiest, fastest, and least expensive alternative fuel to incorporate into our operation,” said Tad Kledzik, supervisor of transportation operations for Pasco County Schools.

Pasco County Schools’ 58 Blue Bird Vision Propane school buses replaced some retiring diesel models from the early 2000s. Each year, the district’s propane-fueled fleet will emit over 72,000 fewer pounds of nitrogen oxide emissions and almost 2,000 fewer pounds of particulate matter compared with the replaced buses, according to the suppliers.

The propane buses are also saving the districts money on fuel. Pinellas County Schools is seeing savings of about 60% per gallon for propane, and Pasco County Schools is saving more than 55 cents per gallon, compared with diesel prices.

Additionally, the school bus fleet operators report saving both time and money due to extended service intervals for coolants and filters on their propane buses, compared to their diesel buses.

The alternative-fuel buses also are quieter, with reduced noise levels by about half compared to a diesel engine, according to the suppliers.

“Our bus drivers have been very happy with the five propane-powered buses in our fleet,” said Scott Reeves, senior coordinator of Polk County Public Schools. “They like that the buses are much quieter than diesel and some have said that they would be willing to change routes to avoid going back to a diesel bus.”

Although there are dozens of public propane stations in the area, some of the school districts chose to install on-site fueling stations due to the convenience and low cost. Installing propane fueling infrastructure costs less than any other transportation energy source, conventional or alternative, according to the suppliers.

James Beekman, general manager of transportation for Hillsborough County Public Schools, said that the district has its propane provider supply mobile on-site fueling, or wet hosing, for its fleet of 50 propane buses that went into operation in January.

“We chose extended range tanks for our Blue Bird Vision propane buses to help with distance,” he said. “And, we can fuel the buses as needed, not necessarily every day.”

Polk County Public Schools takes advantage of the propane fuel station at the local sheriff’s department, while Pinellas County Schools and Pasco County Schools installed private fuel stations. Pasco County Schools has two stations: one with a 3,000-gallon tank, and another with a tank that holds 3,600 gallons. Pinellas County Schools installed an on-site fuel station with an 18,000-gallon tank that opened in January.

“By 2017, we plan to add 40 more propane buses to our current fleet of 58,” said Rick McBride, director of transportation for Pinellas County Schools. “The goal is to have all-propane fleets at the smaller compounds with fueling infrastructure to support them.”

The school districts said that they will consider adding more propane school buses after full evaluation of their current fleets.