Yellow buses could go green

By Chris Cobb
The Herald-Zeitung
Published September 26, 2009

A bus stop in the Ft. Worth suburb of Mansfield might seem an unlikely place to find signs of a global push for clean energy.

But the yellow school buses picking up children every morning, with no smoke piping out of their exhaust, are part of a growing trend to power the nation’s heavy-duty vehicles with alternative fuels.

In move to both reduce harmful emissions and potentially save money, Mansfield Independent School District began transitioning a portion of its bus fleet to run entirely on compressed natural gas in 2007.

“Best program we ever started,” said Charles Stone, the transportation director for Mansfield ISD.

The school district now boasts a fleet of 32 natural gas-powered buses and one filling station, with plans to add another 10 buses and another station in the coming year.

While somewhat unusual in Texas, Mansfield is one of an increasing number of places around the world that is looking to compressed natural gas as a cleaner, cheaper alternative to gasoline.

And Comal County’s government entities are beginning to take notice.

The city of New Braunfels, Comal County, New Braunfels Utilities and the Comal Independent School District are exploring the possibility of having portions of their transportation fleets make the switch to compressed natural gas (CNG).

“They’re all interested in the potential for not only cleaner fuel, but also savings in the long-term,” said Rusty Brockman, the economic development director for the Greater New Braunfels Chamber of Commerce, which is helping all four entities study the possibility of an alternatively fueled fleet. “The benefits appear to be there, not only environmentally, but also in making sure that taxpayers are getting bang for their buck.”

According to the U.S. Department of Energy, heavy-duty CNG-powered vehicles emit far less carbon monoxide than a typical diesel engine, as well as less nitrogen dioxide and particulate matter, which is the soot that spews from a bus’ tailpipe.

One of the benefits for Comal County, according to Brockman, is that cleaner-burning fleets would help the area avoid hitting the non-attainment plateau for National Ambient Air Quality Standards. If air quality conditions in the area are deemed to be in violation of the federal Clean Air Act, it could bring sanctions and regulations, and mean tighter emissions standards for residents.

“We’re all in agreement that we need to make our buses cleaner, especially when you consider those emissions standards,” said Gus Rodriguez, the transportation director for Comal ISD. “But we need to evaluate the cost and see if it makes sense.”

Building infrastructure and either buying buses or retrofitting existing buses to accommodate a switch to CNG comes with a significant up-front cost, although much of it can be offset with grant funding.

Mansfield ISD spent around $2.8 million to build its CNG filling station, buy 26 CNG powered-buses and re-build an additional six diesel engines to run on natural gas, according to Stone. The original cost would have been around $4.1 million, but the school district secured more than $1.2 million in grants from the Environmental Protection Agency, Texas Emissions Reduction Plan, U.S. Department of Energy and the North Central Texas Council of Governments.

“(It would be) a significant investment and we will be thoroughly analyzing how the benefits of such a program match up with factors such as short and long term benefits,” said NBU Communications Manager Gretchen Reuwer in a Friday e-mail.

The DOE estimates that natural gas saves about $0.25 over the equivalent of every gallon of diesel fuel, and says those savings would allow a typical $140,000 CNG-powered bus to pay for itself within three years. Since the fuel burns cleaner, vehicles also have to have their oil changed less frequently.

In addition, the DOE also offers tax refunds based on the per-gallon equivalent of natural gas used, Stone said.

“It looks like that could be a bit of a cash for us,” he said.

But the use of any natural-gas vehicles in Comal County would have to start with construction of a local filling station. Stone said Mansfield ISD spent about $300,000 on its station, and $200,000 of that came from grants.

Any local filling station, Brockman said, likely would be shared jointly by all four entities.

The process is still very much in the exploratory phase, and representatives from CISD, the city, county and utility provider all said any decisions would come down to whether a switch to natural gas would be economically feasible.

“It’s something we definitely have to look into,” said New Braunfels Mayor Bruce Boyer. “If the dollars and cents add up, it would certainly help the environment and set a good example.”



Buck