?Tulsa Transit has 15 new buses to match the rest of its brightly colored fleet, but they are quite different from the rest. 

They are the first of the agency’s 60 long, fixed-route buses that are running on compressed natural gas instead of diesel, which officials say should have a significant impact on both the environment and its budget. 

Public transit buses are major contributors of diesel fumes and emissions, Indian Nations Council of Governments Energy Programs Coordinator Meredith Webber said. 

Tulsa violated air quality standards during the Ozone Alert Season and could be in danger of nonattainment in the future. 

“Buses are on the streets all day. They idle a lot and they stop frequently. So they have a huge impact on our air quality,” she said. “Getting so many buses to go from diesel to CNG will certainly help.” 

Also, Oklahoma is one of the world’s top producers of CNG, so it will boost a local industry, Webber said. 

For Tulsa Transit, which is always strapped for dollars, the move to CNG will drastically cut its fuel budget. 

The agency pays about $2.50 per gallon for untaxed diesel, while CNG is less than half that, Tulsa Transit General Manager Bill Cartwright said. 

Once the entire fleet is on CNG, the fuel budget should drop from $1.5 million annually to $750,000, he said, adding, “that’s just based on current figures, which are always going up.” 

Tulsa Transit in 2009 received $12.2 million in federal stimulus funds through two grants to begin switching its fleet to CNG vehicles. 

Thirty-five of the system’s 50 Lift Program paratransit vehicles have been replaced within the last year with new buses that run on CNG. 

Now with 15 of the 60 long buses on CNG, it amounts to nearly half of Tulsa Transit’s fleet being on CNG. 

About half of the 15 are already on their routes, with the rest set to be on the streets in the next couple of weeks. 

When the rest of the fleet will make the switch remains unknown. 

Tulsa Transit has about $2.5 million left in stimulus funding, but guidelines require it to be used to convert existing diesel buses to CNG or make up the difference in the cost between a new diesel bus versus a CNG model. The money can’t be used to completely purchase new CNG buses. 

Cartwright was eyeing it to fund the conversion of as many as 30 of the agency’s diesel buses to CNG. But problems have surfaced. 

“That is somewhat in question now because of the complicated engineering involved,” he said. 

Since transit buses sit low to the ground so that they don’t have many steps up to board them, the only place to put the CNG fuel tanks is on the roof, Cartwright said. 

“Turns out that the weight of the tanks takes a lot of re-engineering on existing buses,” he said. “It’s kind of a new thing in the industry, and because of that, the cost is very high.” 

The expense would be much higher than originally anticipated, meaning fewer buses would be converted, so officials have to determine whether it’s the best use of the money, Cartwright said. 

Federal guidelines also require the existing buses to be used for a certain length of time, so Tulsa Transit can’t retire any of them early to buy more CNG buses and use the stimulus dollars to pay the difference. 

If the system were to expand, it’s possible the money could be put toward new CNG buses, but that would depend on getting more operational dollars from the city and the state, he said. 

“No decisions have been made yet,” Cartwright said. “But we really have come a long way in the past year.” 

Tulsa Transit’s CNG buses are now being filled at the city’s fueling station. But later this month, the agency’s own CNG station will be ready at its 510. S. Rockford Ave. headquarters. 

It will not be open to the public. 

The station is paid for with a $2.5 million federal Clean Fuels grant and a bank loan of up to $625,000 that Tulsa Transit will repay over three years with the fuel savings realized. 

Fuel costs for Tulsa Transit are completely covered by the city and state, while the agency’s capital costs are largely covered by the federal government. 

Putting federal money toward CNG assets, Cartwright said, ends up making the local dollars stretch further. 

“There are a number of federal grant opportunities out there, and we are aggressively pursuing them to continue this effort,” he said. “I’m confident that in the not-too-distant future we will be entirely on CNG.” 

Article source: http://www.cngnow.com/News/Post.aspx?ID=497