When many of C.A.T. Inc.'s rumbling 18-wheelers make their 3,400 kilometre trip from Montreal to Laredo Tex., the trucks won't be stopping to refuel at the usual diesel pump. Instead, they'll pull into a compressed natural gas filling station.
Coteau-du-Lac, Que.-based C.A.T. is betting big on the potential of natural gas as a cheaper, less polluting alternative to diesel by leasing 100 big rigs that run on compressed natural gas (CNG). The trucks, leased from Ryder System Inc., will mark North America's first major north-south natural-gas truck route.
C.A.T. is replacing almost one-third of its existing fleet with trucks that run on CNG, making the company an early adopter of a technology that is experiencing growing pains and working hard to win over converts.
The North American natural-gas boom, stemming from frenetic shale drilling and fracking, has lowered gas prices and made it an attractive replacement for diesel. But a major challenge for commercial users is the still skeletal infrastructure of fuelling terminals; one estimate puts the number of natural-gas stations capable of accommodating tractor-trailors in the United States at about 300. That has led some major natural-gas engine makers to either discontinue their projects or put them on hold.
Another problem is the volatile energy market. Diesel prices continue to drop, providing less incentive for truckers and other commercial-vehicle operators to make the switch.
"If you're a diesel trucker and the price of diesel declines you keep postponing the decision," said Ken Vieth, senior partner and general manager at ACT Research LLC in Columbus, Ind., a commercial-vehicle consultancy. He added that one factor encouraging a switch is the rise in maintenance costs for diesel engines because of stricter exhaust emission standards.
Other observers point out that natural gas prices could rise if more natural gas is exported overseas and domestic demand increases. A recent Massachusetts Institute of Technology report made the case that it would be easier and more efficient to use natural gas to generate power for electric cars.
Other growth markets for CNG, or liquid natural gas (LNG), include buses as well as garbage and delivery trucks, which usually have short, fixed routes that don't go too far from their fuel depots.
The City of Hamilton is ordering new CNG buses from Nova Bus and New Flyer Industries to add to its existing complement of 35 buses, out of a total of 221 buses.
But the order isn't a huge vote of confidence.
"The goal at this point is to procure CNG-powered buses over the next 6 to 7 years and then to re-evaluate the market to see if there are any other stable technologies (Electric, hydrogen, etc.) that would be able to provide the service in a more efficient and ecologically friendly manner," public works department spokeswoman Kelly Anderson said in an e-mail.
The fact remains that natural gas, touted for "burning clean" and less polluting than conventional fuels, still contributes to global warming.
"In terms of long-term carbon reduction targets, we need to move beyond fossil fuels. This is still not the long-term answer," Luke Tonachel, senior vehicles analyst, energy and transportation program, at the U.S. Natural Resources Defence Council said.
Dependency on fossil natural gas needs to be replaced with the use of renewable methane, such as that derived from biomass, he said.
For now, government tax breaks and other incentives play a role in the development of natural-gas vehicle use.
Corporate raider T. Boone Pickens, a big investor in natural-gas fuelling stations, has been pushing for greater federal and state incentives to encourage vehicle manufacturers to build more natural-gas trucks. At present there is a patchwork of national, provincial, state and municipal programs promoting the use of natural gas in commercial vehicles.