Hybrid diesel trucks: an undiscovered gem of lower emissions HGVs?
This is part four about the challenges that road freight transport companies face when looking at alternative propulsion systems to power their trucks, find part three, two, and subsequently one, here.
With a questionable situation regarding gas-powered truck well-to-wheel emissions and as avenues are being explored on how to continue reducing the impact of business activities on the environment, could another path be towards hybrid technology, at least for the short-term future?
After all, the technology is widely used by private vehicle users, as a typical ride-hailing application’s driver zig-zags the city in a hybrid vehicle from one of the top automakers in the world. Hybrid buses have also appeared on the roads in the European Union (EU), as countries slowly began to adopt the technology to reduce their emissions, as there were over 2,200 buses in the bloc powered by either hybrid diesel-electric or plug-in hybrid diesel-electric powertrains by the end of 2019, according to Eurostat data. Naturally, as battery technology developed, having an additional internal combustion engine made little sense, and slowly alternatives began to take over, as the urban environment is suited for such applications. With many stops and the same routes daily, it is much easier to plan routes and most importantly, charging times and locations. As the infrastructure for zero-emission is still lagging for the transition to mass use across private and public sectors, developing said infrastructure is much easier for such means of transport that have set routes and set parking/rest locations at the end of their working shifts.
That is why some alternative powertrain trucks can be seen operating on port drayage runs, as for example, the port of Oakland, United States, trialed battery-electric and hydrogen fuel cell trucks in November 2019. While following a “feasibility analysis, zero-emissions trucks are not currently affordable, cost-effective, commercially available, or operationally feasible,” the port concluded that “the transition to zero emissions drayage truck will happen, but it is not clear when or how fast.” The port tried its fortunes again in August 2021, as Peterbilt, a subsidiary of PACCAR, the parent company of DAF and Kenworth, delivered 10 of its Model 579EV to Shippers Transport Express, a carrier at the port.
“The fully integrated, battery-electric 579EV in operation by Shippers Transport is optimized for drayage operations requiring two to three trips a day, of up to 50 miles in length before returning home at night to recharge. When used in conjunction with a recommended DC fast-charger, the state-of-the-art, high-energy density battery packs recharge in three to four hours,” stated Peterbilt in its press release announcing the delivery.
Trials and tribulations
While diesel-powered trucks are a long-established technological development that at this point in time, requires little trialing, compared to the newer alternatives.
The mentioned PACCARD subsidiary DAF announced that it started field testing the CF Hybrid in February 2020 with a Netherlands-based carrier. The CF is DAF’s all-round truck model, sitting just below the XF, a long-haul model, in the manufacturer’s lineup. According to DAF, “the CF Hybrid is 100% electric in urban areas and uses clean diesel technology out of town. The innovation truck combines best of both worlds by driving with ‘zero emissions’ in town, thereby ensuring both long-range and flexibility outside urban areas.”
The hybrid boasts a battery pack of 85 kWh, similar to that found in a Tesla Model S, for one, allowing the CF to travel between 30 and 50 kilometers, “depending on the total weight of the truck-trailer combination, which is more than enough to drive into and out of urban areas without producing any tailpipe emissions.”
The executive director of Product Development at DAF, Ron Borsboom, described the trial that while fully electric alternatives are good for city distribution, “clean diesel technology an excellent option for longer distances – partly due to new types of fuel – and for the long term we are having a closer look at hydrogen as well.” According to Borsboom, the company wants to assess not “only its electric/diesel technology performance but also how suitable it is in terms of daily use by our clients.”
Scania, another truck manufacturer based in Europe, announced its own hybrid truck variant that has an all-electric range of up to 60 kilometers. The truck, which was described as a plug-in hybrid, is available with the L- and P-series cabins that are “designed for urban operations,” per the truck maker. According to Scania’s director of New Technologies Anders Lampinen, the plug-in hybrid truck could act as a “bridge between the different technologies, this can help gain valuable experience in gradually expanding fleets to encompass a greater share of electric vehicles.”
There is no doubt that the road transport industry is under heavy pressure to reduce its impact on the climate, as many other industries. The European lawmakers will introduce its newest emissions standard, Euro 7, sooner rather than later, with the expectation that the new rules would come into force in 2025. Per the EC, the initiative‘s public consultation phase has ended and the commission expects to adopt it in Q4 2021.
However, there is also the less prominent pressure to become more environmentally friendly, at least in Europe.
Several cities have introduced low-emission zones that are only set to expand in terms of their urban area and the cities that they are introduced in with the goal to make city centers cleaner for the pedestrians and other actors on the road as well.
“More and more cities have established low-emission zones in centers, requiring alternatives such as electric propulsion. In acquiring the hybrid truck, transport companies can also significantly expand vehicle utilization and reduce unprofitable time while the vehicle is idle. The silent electric mode opens for efficient deliveries also at night, thereby avoiding city center peak-hour traffic congestion,” described the situational use for Scania’s hybrid truck Lampinen. Combined with a diesel engine, the plug-in is seemingly able to do it all, without putting too many restrictions on its operators.
And the zero-emissions zones could only grow. London, for example, will expand its ultra-low-emission zone (ULEZ) on October 25, 2021. For heavy-duty goods vehicles (HGV), entering the ULEZ means paying extra charges, unless the truck is powered by an engine that meets Euro 6 standards. With the world moving towards a zero-emission future, it would not be surprising that slowly some city centers would be walled off for internal combustion engine (ICE)-powered vehicles. Still, a typical long-haul international haulage truck rarely enters a city center, as it mostly operates within the premises of a city, delivering goods to warehouses on the outskirts for the cargo to be distributed in the city itself.
Hybridizing long-haul road transport
The main advantage of a hybrid powertrain is that it can help a vehicle move in the most fuel-consuming instances, as well as allow the vehicle to operate on electricity at certain conditions, or in the case of a plug-in hybrid, drive a certain amount of kilometers.
For a typical long-haul operation, however, there is little urban driving that is done.
Furthermore, since a battery on a hybrid system is charged using regenerative braking, opportunities to recharge the battery on a long drive between two cities in different countries will be few and far between, making it an inefficient usage of the hybrid system.
If a truck arrives at an urban area, where there is a lot of stop-and-go traffic with a low battery level, the hybrid system would not be used to its full potential. As a result, not only the additional cost of purchase is not offset by the fuel savings a hybrid system could offer but also the truck loses out on additional revenue due to the added weight of the hybrid system, reducing the maximum payload of cargo it could carry.
Furthermore, looking towards the long-term future, propulsion technologies will change. Whether trucks will be hydrogen-powered or electric battery-powered, or a mixture of both, is only a question of when, rather than if. If hypothetically, a lot of carriers would begin incorporating hybrid vehicles into their transport systems, it could theoretically lead down the road where these logistics providers would exhibit a sunk cost fallacy, where it would appear to make sense to invest in hybrid technologies, rather than cut their losses and move towards zero-emission technologies.
At the same time, hybrid technologies could still see a window of opportunity due to the aforementioned no or low-emission zones in European cities. With little-to-no emissions-free alternatives currently available on the market, hybridizing a traditional diesel truck could benefit operators for that moment in time when emissions regulations would become harsher, such as the new Euro 7 standard for new vehicles in Europe. The question is what kind of direction will truck manufacturers take, as it all depends on their future plans – ultimately, not every current truck maker has a passenger car division where hybrid propulsion can be thoroughly tested and made cheaper by the means of economies of scale and that could be the strongest counter-argument against hybridizing the road freight transport industry.