Internal combustion engines are expected to provide a cheaper and cleaner alternative to fully-electric powertrains in heavy trucks, according to industry experts.
Advancements in exhaust after treatment and new powertrain technology could mean that diesel and gas powered trucks will provide the cleanest form of propulsion for heavy vehicles, in the medium term.
Emissions from trucks and buses can already be reduced to the same levels as those of the latest passenger cars (Euro 6d-Temp), with technology that is readily available.
Engineers at truck exhaust specialist, Eminox have developed retrofit kits for older vehicles, allowing them to reach Euro VI standards, and the company is working on technology to reduce emissions for new vehicles.
According to Steve Whelen, techincal director at Eminox, one of the biggest challenges with diesel engines, is achieving Euro VI at lower temperatures.
Refuse trucks are especially difficult because the engine rarely gets hot enough for the Selective Catalyst Reduction (SCR) system to become effective.
SCR works by injecting adblue into the exhaust, forcing a chemical reaction which converts harmful emissions into nitrogen and oxygen.
Hybrid trucks also offer the benefit of running on zero-emissions in cities, using batteries instead of the engine for power.
Powering a combustion engine with natural gas provides a further reduction in emissions over diesel, while bio-gas provides even greater benefits.
Refueling a gas-powered vehicle is also a lot less time consuming than recharging an electric one.
While electric power works well for small urban delivery vehicles, it isn’t as good on heavy haulage as the batteries are still too expensive and too heavy.
Fitting more batteries will also increase the re-charging time, which in turn will create extra downtime for the vehicle.