Decarbonising long haul road freight – The Herculean Challenge

While battery electric vehicles are making strides in the transportation industry, they face significant challenges when it comes to long-haul road freight. The large batteries required for these journeys would significantly increase cost and weight, while reducing payload capacity. Additionally, the charging infrastructure, recharging times, and range limitations present further difficulties. Despite these challenges, it is likely that battery electric vehicles will become the go-to choice for urban deliveries. However, for long-haul operations, they are not currently a viable option. Last year (2023) only 0.8% of new HGV registrations were BEV’s, compared to 5.9% of vans and 19.7% of car registrations being BEV’s. These electric HGVs are mainly being used for specific final mile urban deliveries – and not for wider distribution legs.  

Hydrogen fuel cell

Hydrogen fuel cell vehicles have similar refuelling time and range as diesel vehicles, with the added benefit of zero tailpipe emissions. However, they have very high energy consumption and fuel costs, and rely on hydrogen production, which is inefficient, expensive, and still in its infancy. Hydrogen fuel cell HGVs are not nearing the wider market and are unlikely to be ready for high volume production/sale until the 2030’s – making them unviable in the short to medium term.  

Biofuels and synthetic fuels

Biofuels, such as HVO (hydrotreated vegetable oil) and synthetic fuels, developed from combining hydrogen and carbon, can reduce CO2 emissions and be used as drop-in replacements for diesel. HVO is becoming the “go to” solution to decarbonise existing HGV fleets, it is estimated that around 4000 trucks are now running on HVO in the UK. Most Euro 6 diesel trucks can run on HVO without any retrofitting, and switching can reduce emissions by up to 90%. However, there are a few drawbacks; currently there is insufficient supply of HVO for widespread adoption. Plus, generally speaking, HVO costs more than diesel and there are further ethical questions surrounding growing crops for fuel and not food. New synthetic fuels are starting to be developed; however, they have very high energy and fuel costs and the technology and infrastructure to manufacture them is still very much in early development.  

CNG/LNG gas

Compressed Natural Gas (CNG) or Liquified Natural Gas (LNG) is an alternative fuel for vehicles that produce lower levels of harmful pollutants, such as nitrogen oxides and particulate matter, and reduces greenhouse gas emissions. The source of the gas is an important factor in determining the exact number of emissions saved. Biomethane can save up to 80% of CO2 emissions compared with a standard diesel vehicle. The cost of CNG/LNG can vary in comparison to diesel and is generally linked to global gas prices, rather than oil prices. CNG/LNG trucks have seen a rapid growth in the last few years, it is estimated that there are around 2000 gas vehicles running on biomethane in the UK currently. The potential drawback for gas trucks is the reduced refuelling infrastructure, which isn’t as widespread as for traditional fuels, and this can limit the range and flexibility. Operators that have a high proportion of CNG/LNG trucks will tend to have their own on-site refuelling tanks to reduce the impact of this.  

Electric road systems (ERS)

There are three ERS technologies that can charge vehicles in motion: overhead conductive transmission (similar to trams or electric trains), in-road conductive transmission (think Scalextric), and inductive transmission (wireless). Electric road systems are theoretically the most efficient and low-carbon solution for long-haul road freight and are often sighted academically as the future of road haulage. ERS have very low energy consumption and require only small batteries to be installed in vehicles for when they come off the main trunk and arterial roads. Trials have taken place in Sweden, Italy and Germany, with Sweden set to build the first permanent ERS system in the world on a small stretch of the A20 by 2025. In the UK the overhead conductive transmission systems would prove problematic for double deck trailers and oversized loads. Therefore, the in-road or wireless system would be better suited to the UK, and also allow other vehicles such as passenger cars to use it as well. However, ERS relies heavily on government commitment to infrastructure programs to make a reality, and at the earliest it would be the late 2030’s before any such system could be widely adopted in the UK.