Representatives from two of Canada's most experienced liquefied natural gas (LNG) truck fleets opened up about their experiences with the technology during a candid conversation at the first annual Natural Gas Vehicle Infrastructure Canada conference here today.
Both Trevor Fridfinnson, senior vice-president with Bison Transport, and Yves Maurais, engineering manager with Robert Transport, were refreshingly honest when discussing how well, or not, LNG trucks have worked for them.
Robert currently runs 115 LNG Peterbilts and is two years into its project, while Bison deployed 15 LNG Petes early this year and is approaching its first million miles.
Bison is running its LNG trucks in its long combination vehicle (LCV) fleet between Calgary and Edmonton. When the project was launched, the company envisioned a two-year payback. Fridfinnson now admits that won't happen.
"It's not going to be possible to hit that timeline," Fridfinnson said. "Where it ends up, I think that remains to be seen because we think there are further efficiencies that can be drawn out of this particular model, but suffice it to say, it is an extended timeframe."
Bison normally runs tractors in its LCV fleet for just five years, which is why a quick payback was hoped for. However, fuel economy and maintenance costs have derailed those initial ambitions.
Fridfinnson said Bison went into the project expecting a fuel economy degradation of about 10% when moving from diesel to natural gas.
"Today we're tracking at just around 5 mpg on the LNG tractors and around 6 mpg on our comparable diesels, so we have a difference there that's 17-18% as opposed to the 10% we were targeting," Fridfinnson said. He remains hopeful that the considerable gap can be cut in half as the company familiarizes itself with the technology and realizes further efficiencies.
One of the problems is that the LNG fuel tanks eat up a lot of frame rail space, requiring a longer wheelbase and larger trailer gap, which hampers fuel economy. Bison has added some tractor fairings in hopes of addressing that issue.
Bison also has learned that its LNG tractors aren't getting the 550-mile range they had predicted. Instead, they are achieving about 450 miles.
"For our purposes, it mostly works," Fridfinnson said of the range. "But there are times in less optimal operating conditions where we can run closer to the line than we want to be."
Maintenance costs have been another unpleasant surprise. Diesel-powered LCV tractors in Bison's fleet normally incur maintenance costs of three to four cents per mile, Fridfinnson said.
"These (LNG) trucks have had an inordinate amount of issues," he admitted, noting their maintenance costs have run about seven to eight cents per mile - or double their diesel counterparts.
The biggest issues have involved sensors, gauges and software related to the LNG fuel system.
"I will say, those things have moderated over time and I will give props to our supplier partners for their attentiveness to make sure we're not out there on our own trying to deal with these types of things," Fridfinnson said.
Bison is still committed to the project, he added, but enthusiasm - even among customers - seems to have waned in the face of so many disappointments. Fridfinnson said he's confident there are opportunities to improve fuel economy and reliability, but was non-committal about adding more LNG trucks.
"Certainly we've run into more obstacles than you ideally want to face in the initial rollout, but we remain strongly committed to the concept and to exercising it fully," he said. "Whether or not we expand it is yet to be determined. We're nine months in, so we still have room to do some fine-tuning."
Robert Transport, which has been running its LNG tractors for two years, had a markedly better story to tell, though blazing the LNG trail hasn't been without its challenges. Maurais said Robert was surprised by how much diesel the 15L Westport GX engine consumed. Because it's compression ignited, it requires diesel to initiate the combustion cycle. Robert expected the diesel consumption to be about 5% of total fuel consumed, but it has turned out to be closer to 10%, Maurais noted.
One of the biggest issues Robert encountered was the additional weight the LNG tanks contributed. The first of its trucks were overweight by US standards on the steer axle the first time they were fuelled up. A day cab with one LNG tank added 546 lbs compared to a diesel equivalent and a sleeper cab with two LNG tanks weighed 1,149 lbs more than a diesel.
Another issue was that the in-cab methane detectors sucked power, requiring additional batteries - and more weight - to be added to the vehicles. Not to be deterred, Robert has begun adding solar panels to the roof fairings to power the methane detectors and air-conditioning systems.
The tanks - for diesel, natural gas and diesel exhaust fluid - competed with APUs for frame rail space, requiring a longer wheelbase and adding to the trailer gap.
"Using sleeper trucks, it's very hard, almost impossible, to get the truck shorter than a 220-inch wheelbase, so it makes for a very long truck," Maurais said.
On the plus side, Robert has substantially reduced its greenhouse gas emissions. Maurais said GHG has been slashed by 58% in LCV applications when compared to pulling two trailers with two diesel-powered tractors. And unlike Bison, Robert is getting fuel economy that's nearly equal to its diesels.
Maurais pointed out that the Westport GX uses the EPA07 generation Cummins ISX as its base engine. Therefore, comparisons should be made against the EPA07 engines - not the more fuel-efficient 2010s.
The GX engines in Robert's fleet are getting fuel economy equal to its trucks with the EPA07 Cummins ISX15 diesels.
"These trucks have been in service now for 18 months to two years, so we're figuring out that the break-in period of these engines is a lot longer than a regular diesel engine," Maurais said. "It could be up to 200,000 kms before we get optimal fuel consumption."
He believes the Westport GX engine can equal comparable diesels for fuel economy.
