This article was originally published in BIV Magazine's Trade issue.
When it comes to decarbonizing the economy, pretty much everyone in the sustainable energy field agrees aviation and long-haul trucking will be the last mile on the road to net-zero by 2050.
“Of the on-road applications, long-haul trucking is probably the single most challenging,” says Gordon McTaggart-Cowan, professor of sustainable energy engineering at Simon Fraser University.
Transportation accounts for 25% of Canada’s greenhouse gas (GHG) emissions, with heavy trucking accounting for 35% of that, or 9% of total national emissions. Globally, it’s estimated that heavy-duty trucking accounts for only 4% of the vehicles on the road, but 27% of road emissions.
There are 60,000 heavy-duty trucks (vehicles that weigh at least 25 tonnes) registered in B.C. and 156,000 medium-duty trucks, according to the BC Trucking Association. They emit slightly more carbon dioxide (CO2) than the 2.2 million light-duty vehicles in B.C.
Converting buses and medium-duty trucking to battery electric or natural gas engines that run on ever-increasing amounts of renewable natural gas is feasible, says Dave Earle, president of the BC Trucking Association. In fact, it’s already starting.
“In the long-haul world, this is where it gets scary,” he says. “We are literally decades away in the long-haul world.”
Indeed, projections by Bloomberg New Energy Finance and IHS Markit suggest that 70% to 80% of heavy-duty trucks will still be running on diesel or natural gas in 2040, with only about 19% electrified.
The long-haul sector faces a mountain of barriers – including actual mountains – when it comes to switching from diesel to zero-emission fuels or power sources.
One is physics, notably energy and power densities and energy transfer. The longer the range, the heavier the load and the steeper the grade, the more that energy density and energy transfer become limitations, and there are few fuels as energy dense and efficient as diesel or gasoline.
Then there’s the chicken-and-egg problem of fueling infrastructure – regardless of whether that fuel is electricity, hydrogen or biofuel – and the range anxiety that goes with it. But the biggest hurdle is fleet turnover, Earle says.
A diesel engine for a Class 8 semi truck can last up to one million miles (1.6 million kilometres) for an average lifetime of 15 years. The average year for a heavy commercial truck in B.C. is 2008, Earle says, with a 3% turnover per year. Even if the technology, infrastructure and fuels were widely available today, which they’re not, it would take 25 years to convert the entire fleet, Earle estimates.
“That assumes you start turning it over today,” he adds.
The medium-duty and, in some instances, heavy-duty trucking sector can switch to battery electric or natural gas (which could be displaced with renewable natural gas, as it becomes available) for local and regional routes.
Fleet operators with return-to-base operations would be able to charge or refuel their trucks at base each night, without needing to find recharging or fueling stations in the communities they serve.
ColdStar Solutions, which operates a fleet of refrigerator trucks, has already begun making the switch. Of a fleet of 35 company-owned trucks, 25 run on compressed natural gas (CNG), which produces fewer emissions – including CO2 – than diesel. The company has also put in its first order for a battery-electric reefer truck.
“Our goal is, by the end of 2023, our trucks will be 100% natural gas or electric,” says ColdStar CEO Kelly Hawes.
One advantage of CNG and liquefied natural gas (LNG) is that no engine modifications would be needed, should a sufficient supply of renewable natural gas (RNG) become available as a zero-emission drop-in fuel.
“There just isn’t enough supply at this point,” Hawes says.
While starting with CNG and LNG, and converting eventually to 100% RNG, is a solution for some sectors of trucking, long-haul trucking once again poses a problem. Natural gas is not as energy dense as diesel, so it has limitations when it comes to heavy loads and long distances.
“We’ve got carriers where the bulk of their fleet is natural gas because it works,” Earle says. “We’ve got other carriers that have tried it and said it just doesn’t work because it doesn’t have the energy density.”
As for biodiesel, it can reduce emissions intensity, but at a certain percentage it can gel and foul engines.
“Biodiesel is a nightmare,” Earle says. “Because of the chemical makeup of it, it gels in cold weather.”
So what about battery-electric trucks? Despite efforts by Tesla, Inc. to develop a battery-electric semi truck, battery electric has some serious limitations for long-haul trucking.
After visiting PACCAR Inc.’s research and development division in Washington State, which builds prototypes for low- and zero-emission trucks, Earle came away fairly skeptical about the prospects of applying battery-electric solutions to long-haul trucking.
A major problem is the weight of the batteries needed to power a semi truck – a problem that gets compounded in cold weather, which reduces battery efficiency. While Tesla says its semi would have a range of 475 to 800 kilometres before needing to be recharged, a typical diesel semi truck has a range of 1,000 to 1,500 kilometres.
Earle has done the math, which looks like this: 1,200 metres, vertically, with perfect fuel efficiency requires 100 kilowatt hours of power, which is the vertical lift of a run from Hope to the Coquihalla Summit.
“That’s about two Tesla model threes,” Earle says. “If you look at the current batteries that are available, you could conceivably run a load from the Fraser Valley to the top of the Coquihalla summit on a 400-kilowatt battery and need to charge at the summit. That ain’t going to work.”
One carrier is currently trialling an electric semi truck between Vancouver and Puget Sound, Earle says. To date, those trials suggest that what now takes four trucks would require six electric semis to move the same amount of freight.
At a recent forum on decarbonizing transportation hosted by the Greater Vancouver Board of Trade, Randy MacEwan, CEO of Ballard Power Systems, said hydrogen fuel cells can addresses the decarbonization problem for the long-haul sector.
“When you have heavy vehicles, heavy payloads that have long range and high utilization requirements, we see an opportunity for hydrogen fuel cells to decarbonize these segments, and to date they’ve been very difficult to abate,” he said.
He’s not the only one who thinks fuel cells may win over battery electric for the long-haul sector, or at least some segments of it.
“We also see, for long-haul, there’s a few challenges with the battery electric technology,” says Joanna Kyriazis, senior policy advisor for Clean Energy Canada. “As much as battery technology is kind of winning the race in a lot of these other vehicle segments, a lot of people are holding out for hydrogen on the long-haul side.”
To date, there are no fuel cell semis on the road, except in trials. Daimler recently announced its new GenH2 semi truck, powered by hydrogen fuel cells, with a range of 1,000 kilometres. The company will begin customer trials in 2023, with production scheduled for 2027.
This article was originally published in the July 2021 issue of BIV Magazine under the title 'In it for the long haul.' The digital magazine can be read in full here.