GEORGETOWN, Texas (KXAN) — Georgetown Independent School District will buy 33 new school buses to replace more than a quarter of its aging diesel fleet with vehicles that run on propane.

The district says the new buses will be cheaper to operate and maintain and will cut emissions substantially compared to the ones they’re replacing.

“Diesel prices fluctuate quite a bit throughout the year. Propane prices stay pretty consistent over the years,” GISD’s director of support services Kirby Campbell said. “It’s about half the cost of what we pay for diesel fuel.”

Campbell estimates the district will save $75,000 a year in fuel costs alone by converting part of its fleet to propane. He planned to present the proposal to GISD’s board of trustees for the first time Monday evening.

The district is using $1.3 million in grant funding from a couple of different programs under the Texas Commission on Environmental Quality (TCEQ), plus bond funding approved by voters last fall to buy the new buses.

GISD still has to come up with about $300,000 to fund a propane fueling station. Campbell hopes to be able to use some of the grant or bond money to build it.

Campbell is familiar with the TCEQ grants. In 2008 he worked for Leander ISD and spear-headed that district’s efforts to convert part of its fleet to propane power. The district bought more of them last year, bringing its total to 127 propane buses, or about 30% of its fleet.

TCEQ makes millions of dollars of grant money available every year under the Texas Emissions Reduction Plan to allow school districts and other agencies with big fleets to replace or retrofit old diesel vehicles with alternative-fuel vehicles or modern, cleaner diesel engines.

Georgetown received funding from both the Texas Clean Fleet Program and the Texas Natural Gas Vehicle Grants Program for the propane buses, plus an additional $245,000 from the Texas Clean School Bus Program to replace five more buses with cleaner diesel engines.

The goal is to reduce emissions of nitrogen oxides, commonly called a family of poisonous gases produced by burning fuel. The compounds are powerful greenhouse gases and can be harmful to respiratory health. Propane and newer diesel engines produce far less of the pollutants than older diesel engines, and some of the buses GISD is replacing are 27 years old.

TCEQ estimates 20 propane buses Leander ISD bought in 2016 through the Clean Fleet Program reduced the amount of nitrogen oxides reaching to the atmosphere by nearly nine tons. Over the life of that program, TCEQ reports agencies around the state have reduced emissions by more than 633 tons.

The Natural Gas Vehicle Grants Program has been even more effective, reducing nitrogen oxides emissions by nearly 1,500 tons since 2010. The Clean School Bus Program, which only recently started funding replacements, has prevented more than 51 tons of the pollutants from getting into the air.

Converting a quarter of its fleet to propane power will be better for the environment and for students, Campbell said, adding bus drivers are also looking forward to the new rides.

“It’s kind of like getting a new car, right?” he said. “So you get a brand new bus with all the bells and whistles of a brand new bus. And [they’re] really excited to be on the propane because they’re quiet, clean-burning.”

The district plans to roll out the buses in November.