Getting power to depots
For a while now, those of us at the forefront of road freight electrification have been considering several issues… for instance, getting power to logistics depots, especially when we will need many terawatts to get the UK fleet electrified. Increasing development of microgrids with solar will help, whilst forward planning grid connections for purpose-built logistics parks will too. However, both these moves only go so far and when you look at the biggest HGV fleets, these are going to be some serious power guzzlers once they’ve switched to electric.
The weight penalty
A second issue, which has emerged from early adopters of eHGV, has been the weight penalty of carrying the large battery packs needed to achieve the ranges of up to 300 miles now possible with the latest vehicles. This results in reduced capacity and is in danger of making eHGV less attractive as a technology, at least until battery tech has evolved further to make the cells lighter, but this is some way off. The UK government could address this by increasing axle weight limits, but this would put a strain on bridges and other infrastructure that may not easily take the additional loads.
But there is another way!
There is a solution out there however that would help with both these issues and it’s one that has perhaps not been given the consideration it should have had. That is Electric Road System (ERS). This involves the slow lane of key motorways and major A-roads being equipped with power lines, either in a catenary or in-road conductive setup, which eHGVs then take power from. The vehicles consequently have a much smaller battery, which is sufficient for them to get from the exit lane to a logistics park. Weight limit problem solved!
The ease of grid connectivity is not to be overlooked, as instead of needing large connection points at thousands of depots, the major connections from the grid are into the catenary where motorways already cross the grid.
And a bonus benefit…
Another benefit is around time spent charging. If the depot top-up requires less energy to go into the battery then it won’t take as long for a given charger capacity and so the potential for impact on schedules and operations will be lower, even when vehicles are running around the clock. A charge during a short load or unload slot may be sufficient versus a longer dwell that may have been necessary with a larger battery. In many cases it may not be necessary to charge at all, as all the charging can happen out on the road whilst tracking along the main ERS routes.
The big picture
A final benefit of ERS is one around efficiency and TCO, since smaller batteries mean lower cost vehicles. Whilst there’s still a very significant investment needed in the network itself, running into tens of billions of pounds, this pays for itself once you look at the maths on a large scale. According to the Centre for Sustainable Road Freight, a UK wide network covering 76% of HGV miles could be built for approximately £20bn by the late 2030s if started in the late 2020s. ERS would then handle the heaviest, longest journeys on major routes, whilst the remainder of road freight that hasn’t moved to rail would then transition to a standard BEV eHGV. This accepts that there may be weight limitations and megawatt chargers needed for remote locations away from the ERS network.
And then the global picture
As a sign that the technology works and has traction, the Chinese are pressing on with five separate ERS demonstrator projects, using overhead contact lines. In Europe we have 3 separate catenary projects and 2 inductive road projects in Germany, along with inductive projects in France and Italy, plus a conductive rail project in Sweden, each of which have shown the viability of electric road systems. So why aren’t we getting on with it in the UK then? We did come very close to launching a project on the M180 in 2022, where 26 miles were due to be turned into an ERS demonstrator.
And the next steps?
Perhaps it’s time to look at this again, particularly given the weight challenges being encountered in early projects and the depot power connection challenges that are starting to emerge.
Leo Pickford
Founder and chief executive, Transitionwise
