E-highways: the solution for reducing HGV emissions?

In the UK, 18% of all vehicle CO2 emissions are from HGVs, despite only accounting for 1% of road traffic. Electric vehicles are commonly agreed to be the long-term solution, but while batteries are effective for short-range and city delivery, two-thirds of the industry are long-haul and would require on-road dynamic charging. The alternative is waiting years for expensive (and not yet developed) long-haul battery solutions.

The current limits of battery technology mean that electrifying HGVs with existing rechargeable batteries is not viable due to their size and the long-haul nature of their use. Tesla’s Semi demonstrates this. The weight of the batteries required would significantly increase the cost and raises questions about efficiency, as the vehicle would need to be off the road to charge for a significant amount of time.

As part of the government’s £20 million investment into zero-emission road freight trials, a nine-month trial of the UK’s first e-highway is underway to determine if it would be feasible to implement nationwide. The feasibility study is due to report at the end of March 2022. Providing the study sees potential, a 19-mile stretch of the M180 has been identified as the location for a pilot scheme. 

An e-highway uses dynamic charging to allow electric trucks to charge while driving, meaning that they would switch from e-highways to regular highways seamlessly and would not require charging stops. The cost of purchasing and replacing batteries would also be reduced, saving both fleet operators and the environment.

This would be executed by installing overhead powerlines, similar to those used by trains. The lines would be out of reach of other road users – not affecting their journeys. With this solution, upgrading roads would be comparatively quick and affordable, minimising road closures and delays.

According to the report by the Centre for Sustainable Road Freight, implementing this type of electric road system is estimated to cost £19.3bn and could make 65% of the UK accessible to long-haul electric vehicles by the late 2030s. The cost of implementation and the energy savings could see the investment pay for itself within 15 years.

While the technological and environmental arguments are strong, there are still questions over the practical implementation. A good example of this is how vehicle excise duty (VED) will be collected when entire fleets are running on electric rather than fossil fuels. Haulage companies would likely be charged for the construction of infrastructure to support this enormous project through taxation, as well as paying for the energy itself.

In an industry where there is currently little room to manoeuvre due to increasing fuel costs and the driver shortage, the lack of certainty about tax rates means that fleets are more likely to wait and see rather than jump in as early adopters.

With so many alternative solutions for reducing emissions still being trialled, there is a lot of uncertainty about not only which is the most effective, but the most realistic carbon reduction strategy in terms of ease and speed of implementation. Until a uniform approach is agreed on by governments or the industry itself, many fleets will simply stick with the status quo.

Even with the approach agreed upon, the e-highways system would require both compatible vehicles and new road infrastructure. The complexity of making compatible trucks affordable and preparing the roads simultaneously means that there is likely to be a period where e-highways are completed but severely underutilised.

While trials are new in the UK, e-highway systems have been in development for over a decade in Europe. In Germany, the first demonstration began on a private road in 2010 – a 2.1 km highway test track. The first public e-highway opened in Sweden in 2016 on a stretch of the E16 motorway between Gävle and Sandviken.

There are now three projects in Germany totalling around 15 km, including a 5 km stretch of motorway near Frankfurt Am Main. This is a small number nationwide, but it shows how this concept could be integrated alongside standard roads. Based on these systems, the National Platform for the Future of Mobility (NPM) has suggested installing overhead contact lines on 300km of motorways in Germany by 2023, moving towards a total of 4,000km by the end of 2030. The expansion looks set to continue in both countries, with the Swedish Transport Administration developing a plan for how 2,000 km of the busiest roads in Sweden can be converted by 2030.

While hydrogen and biofuels are touted as common green alternatives to electricity, they are thought to be inefficient due to the creation and conversion processes using almost three times as much energy as the e-highways. They also raise some of the same issues – a lack of existing infrastructure in place and not enough compatible vehicles.

With questions over the alternatives, electric overhead rails could be a viable mid-term solution that ensures that the UK government’s pledge for zero-emission HGVs by 2040 is met. However, this is unlikely to be the only source of power. With just 65% of the UK expected to be covered by e-highways in the initial rollout, a new form of a hybrid vehicle could likely emerge – trucks with the ability to run on hydrogen or biomethane, but also connect to e-highways where available.

Read more about the challenges of reducing emissions in our article it is not easy being green.