INDIANAPOLIS, Ind. — For Chuck Diehl, fleet manager with Smith Dairy, the fuel of the future is natural gas. His company is transitioning its truck fleet to natural gas and has recently opened its first CNG retail station.

For Tony Greszler, vice-president of government and industry relations with Volvo, the customer will ultimately decide the fuel of the future, but dimethyl ether (DME) holds special promise.

The pair hosted a break-out session on future fuels during the Green Truck Summit here yesterday.

Greszler said of all the future fuels being considered, DME has some unique attributes, which make it appealing. It can be derived from natural gas or biomass without some of the weaknesses associated with natural gas, such as its tendency to boil off in liquid form. Also, Greszler pointed out, natural gas, when vented, releases methane, which is a harmful global warming-causing pollutant. DME does not.

“The data out there is still sketchy,” he said of the true GHG impact of using natural gas as a fuel. “As we’re learning, there’s concern about methane emissions all along the extraction and distribution (of natural gas) that has a huge impact on its GHG signature.”

The amount of methane emitted in the extraction and consumption of natural gas is “starting to get a lot of scrutiny,” Greszler pointed out.

DME is a cleaner fuel that can be derived from a wide variety of fossil- and bio-based materials, natural gas being one of them. It’s easy to store and transport, liquefies at low pressure, doesn’t have any venting issues, boasts a high well-to-wheel efficiency and burns with diesel-like efficiency, Greszler explained. It creates no soot, eliminating the need for a particulate filter, is non-toxic, provides adequate power density for long hauls and has minimal global warming potential.

Also, Greszler added, there are a number of suppliers who say they can make the fuel at a low cost. What’s lacking is the trucks, though Volvo has 10 trucks running on DME in Sweden, which now have more than a million kilometres of experience and have been performing without any problems, Greszler explained.

For Diehl, natural gas was the most practical and immediate way of greening up his truck fleet’s environmental footprint. The process began with an environmental impact study, once all the obvious solutions had been deployed (trailer skirts, wide-base tires, idle-reduction, etc.)

As part of its lightweigting process, the second diesel tank had already been removed, so the limited range of natural gas wasn’t a huge deterrent. In researching natural gas, Diehl noticed that 67% of the cost of diesel is directly related to the cost of crude, whereas in natural gas, only 20% of the cost is attributed to the raw material. This led Diehl to believe there would be far less price volatility with natural gas.

Without a fuelling network near Smith Dairy’s Orrville, Ohio home, the company set about opening its own CNG retail station, a process that took just 90 days from when it broke ground. Diehl admitted the company wasn’t sure how much demand there’d be for CNG, aside from its own trucks, but surprisingly it now sells more gas to customers than it uses in its own fleet.

The transition to natural gas has not been without some unexpected surprises along the way. Diehl admitted he was disappointed he had to remove the waste oil heaters he installed in the shop just five years ago.

“Five years ago I looked great when we put them in, but not today,” he said.

Smith Dairy is now expanding its natural gas-powered truck fleet, with four Freightliner and six Peterbilt dual-fuel trucks in the process of being ordered. These vehicles will be capable of pulling full 80,000-lb loads.

By 2030, Diehl said, the company hopes to be “diesel independent.” Currently, Smith Dairy’s commercial CNG station is retailing the fuel at $1.95 per gallon, with an undisclosed profit built into the price.