C-Tran begins testing of renewable diesel

May 27, 2020
The agency says maintenance cost per mile and fuel cost per mile have both dropped on vehicles using the renewable diesel.

C-Tran is now testing renewable diesel as an alternative fuel source.

This follows C-Tran's addition of its first hybrid buses in 2008, which now account for more than half of the fixed-route vehicles the agency has in service.

C-Tran started testing renewable diesel in a limited number of in-service vehicles last summer, evaluating a series of detailed metrics and overall performance to see how it stacks up against traditional diesel fuel – and to make sure it’s a sound investment for the agency. C-Tran also wanted to make sure it achieves the sustainability goals.

“It’s not just dollars and cents you’re weighing,” said C-Tran Director of Maintenance Tim Shellenberger, who oversees fleet maintenance.

So far, the agency says results look promising. The maintenance cost per mile and fuel cost per mile have both dropped on the vehicles using renewable diesel since they made the switch. And renewable diesel is cleaner burning, creating less emissions, Shellenberger says. As a result, it’s easier on the exhaust after-treatment systems that are installed on our buses. That ultimately lowers the time and cost required to maintain them.

Renewable diesel is made entirely from animal fats and vegetable oils. C-Tran is currently testing buses using a blend called R50, which is about half renewable diesel and half traditional ultra-low-sulfur diesel – what is used on the rest of the fleet. R99, by comparison, is essentially all renewable diesel.

C-Tran purchases R50 renewable diesel through a shared contract with Clark Public Utilities. It’s supplied by Carson Energy. The agency will be proposing to expand its renewable diesel test to include the entire fleet with R99 starting next year. After a two-year pilot, C-TRAN would then make an informed decision on whether to stay with renewable diesel or pursue a different direction, Shellenberger says. The two-year pilot would first be approved by the C-Tran Board of Directors.

“We have to do our due diligence,” Shellenberger said. “Not only to transition to an alternative fuel vehicle for new bus procurements, but what about our existing fleet?”

That’s one of the benefits of renewable diesel offers compared to other alternative fuel options: It’s interchangeable with traditional diesel and doesn’t require any new infrastructure or special vehicle types. It can be used with C-TRAN’s existing fleet.

“What’s the cost to transition? Nothing,” Shellenberger said. “Just drop it in, and away you go.”

The price per gallon of renewable diesel is higher than traditional diesel. That’s no small consideration for an agency like C-Tran that uses more than 1 million gallons of fuel per year. But the cost savings on maintenance and engine performance could make up some of that difference. And C-Tran’s carbon emissions could be lowered as much as two-thirds by going to all renewable diesel, Shellenberger says.

 C-TRAN will also introduce the first all-electric buses into its fleet in the coming years.

“The goal is to become zero-dependent on fossil fuels while decreasing our carbon footprint,” Shellenberger said.