In the path towards sustainable transport and logistics, the one thing that does seem to be beyond debate now, is that electric LGVs are coming, and they will be here to stay. The question we are posing is how will they work and what alternative approaches can we take to make them a success?
There is no doubt that the tide towards electric vehicles is only going one way. We have previously written about the challenges of electrification, and how hard it will be not only the UK, but countries across the world to develop infrastructure to meet the power draining needs of this equipment.
There are still players in the market pushing alternative fuel tech technologies such as hydrogen cells, and no doubt these will make some inroads into the sustainable logistics market as well. However, with Mercedes-Benz, Volvo and others already producing and selling electric tractor units, and the much anticipated Tesla semi-truck not too far down the road, it is time to perhaps think laterally about how we accommodate these vehicles.
So far, in most circles, the conversation around electric LGV has revolved around vehicle range and charging. And quite right that it should, as we in the industry know that LGV transport legs tend to be very long, and that charging tends to take quite a long time. That time costs in truck unproductivity and driver working hours. (Note to self on this…will time waiting for charging to complete be classable as rest, or will it fall into ‘other work’ or ‘period of availability’?)
The new fleets of electric LGV that are coming to market now are all promising extended range versions with supercharging capability up to the megawatt solutions that claim to be able to charge LGV sized batteries in 30 to 40 minutes. This will indeed be quite a feat, and one that would add a great deal of flexibility to the market.
The problem that we see with this is the sheer lack of available power grid to be able to install enough megawatt charging locations, not only at strategic locations around the country, but also at Haulier and truck operator distribution points and yards. In some areas it is hard enough to get a modest amount of power even to be allowed to install what may be termed as ‘trickle charger’ points at distribution centres just to charge the electric company cars. The chances in most areas of being able to install megawatt charging points, and multiples of them, are pretty slim, for the time being at least.
And there is another factor that we must not overlook. Those of us who have electric cars know that the quoted maximum range is almost certainly never achieved. We are also told that we must typically not charge the batteries beyond approximately 80% as a matter of course, nor should we allow them to run down to near empty. Who wouldn’t be frustrated at the fact that your EV driving range in winter is way down from summer performance. We must consider these factors when looking at how we would plan the transport trips being carried by electric vehicles, as these factors will almost certainly be present for LGV EV as well.
Then, we must also consider the effect of EV trucks on the payload capacity of the vehicles they are pulling. Comparing the as yet unpublished kerbside weights of, for example the Tesla semi-truck with that of a standard diesel tractor unit such as the Daf XF, you will see that we expect the electric semi truck to weigh in at approximately 10.5 tonnes. A Daf XF depending on specification weighs in at 7.5 to 8 tonnes. Clearly these additional tonnages, that are effectively made up of huge battery packs for the electric LGV vehicles are going to diminish the potential payload capacity of the trailers they are pulling. According to the RHA survey reported on by Motor Transport on 9th April this year, it is estimated that standard 44t UK LGVs will lose11.8% of their payload capacity due to the weight of the EV Tractor Units.
What may be more of consequence however, is our concern that the bigger problem might actually come in the axle weight capacities of the electric trucks. With the amount of weight slung between the drive and front axles of the electric truck motive unit, once we have a vehicle with a full payload, there may be significantly increased pressure on the drive axles, leading to potential overweighting for those axles. Those in the industry are well aware of the penalties for driving overweight be it on one axle or across the entire vehicle.
So how do we get around this issue of payload and axle weights? Well there is one thing we would expect and we call upon governments to consider to help support the push towards vehicle electrification. We believe it is right that given the lack of emissions from electric vehicles, that a scheme be put in place to enable LGV with electric motive units to be allowed to carry 46 tonnes on UK roads.
This would effectively balance out the two or so tonne payload differential between the electric motive unit and standard diesel. We could argue that it may also be worth adding an additional 2 tonnes of EV trucks to provide a premium incentive of available payload to actually provide benefit to EV trucks. This however, will likely cause problems with axle weights, and we will discuss this further below.
A particular reason we suggest this is that it is broadly acceptable that carrying increased weight on an electric vehicle has a much lesser impact on the efficiency of that vehicle versus a standard diesel truck. For EV LGV, the wind resistance and drag coefficient at speed is a much higher influencer of vehicle efficiency, and the efficient aerodynamic design of new vehicles will help counteract that. There is also the fact that when carrying a heavier load, the regenerative braking systems on an electric LGV can actually increase efficiency significantly in start stop traffic situations versus a diesel LGV, adding further to the potential benefits of these as a solution.
On the other hand, desel trucks are, as a rule more sensitive to weight as a factor in efficiency than EV. The more weight you add to a diesel load, the disproportionately greater the impact on its efficiency and therefore carbon footprint.
To be able to increase payload for EVs it would of course carry the usual quandaries regarding effect on already under invested road infrastructure in the UK and abroad. This of course is an issue, and one that we call upon the government to firmly get a grip of. But we all know that roads are engineered to be able to accept loads significantly more than the current legal limits. And in its simplest terms, more payload per truck means fewer truck miles on the road.
So, a sustainability premium is one method to help drive potential operators who would consider electrification in that direction and away from diesel.
But we would also like to put out an alternative option. This option is not one that would work for every fleet operator, but we must consider the significant amount of transport operations that are carried out within ‘captive’ networks. When we say captive networks, we mean the kinds of transport operations that are carried out by the likes of the big retailers, and the large scale hub to hub haulier operators. These operations are typically where the tractor unit and trailers tend to start at one base and typically return to that base either at the end of the day or multiple times throughout the day.
Why is this important you ask? Well, far be it for us to tell industry luminaries such as Elon Musk that they may be not looking at things from the right perspective, we believe there is a fundamental trick being missed in the potential to electrify vehicle fleets, and the focus on bringing lt to market.
The EV LGV tractor units coming to the market now all suffer with the same issue. They are extremely heavy because the tractor units carry a huge amount of battery cells within the base of the vehicles. (The batteries are typically always within the base to make sure the vehicles are stable and have a low centre of gravity by the way.)
These electric vehicles are being designed to try and replicate as best they can, the way a standard articulated tractor unit operates. They go out on the road pulling one trailer, they come back to the DC. They drop their original trailer pick up a loaded trailer and off they go again. In that cycle, we are all hoping that the LGV operator can quickly charge the electric motive unit at its base location for the 30 to 40 minutes it needs to send the vehicle out on another long-distance run, and maybe do the same at the far end of its trip. Please refer back to some of our first points, we think this is likely to be highly challenging to get the amount of super-high-power chargers spread in the right places, with the right capacities.
So what might we suggest that may twist Elon Musk‘s melon? Well, our challenge is, why are we putting so much effort to load up the tractor unit with so much battery power? Why don’t we look in captive operations to actually load the battery packs spread out under the floor of the trailer? These battery packs can easily be charged while the trailer is at base unhitched and / or being loaded, using a much more reasonable level of power, rather than requiring a dynamic high-powered charge.
The batteries slung under the floor of the trailer can then be connected via a very easy connection plug (a 21st century version of the Suzi pipe) to power the motive unit when one comes along. It may be possible in that case to actually put a significantly larger amount of battery capacity into the trailers to therefore enable a much longer load range for those vehicles.
There are a couple of distinct options that this type of approach could provide. Firstly, it may be possible to reduce down the amount of batteries and therefore the weight in the motive units. The motive unit would always need their own battery power, so that they can move independently of their trailers. But if this was reduced by a half or more to simply be enough to pull the motive unit when it is unhitched, or to cover shorter day-runs, then the weight of that tractor unit can be reduced significantly.
But then think about how we could potentially significantly reduce the impact of the super heavy batteries on the drive axle situation that we mentioned earlier. If the weight was evenly spread throughout the full length and width of the trailer, with an equal balancing in the motive unit, then we foresee a circumstance where the actual axle weight pressures could be much more evenly balanced and a heavier payload vehicle may actually spread the load better and put less pressure per axle on the road. This would be an offset to the argument about the potential wear and tear to the road surface of heavier vehicles, and could actually open the way to enabling larger capacities overall across the network.
We have calculated, that to stay within the legal axle weight limits as they are now, and to level the payload weight capacity of an E-LGV versus a standard diesel truck, the maximum GVW for an EV should be increased to 46t. Simply increasing the maximum GVW will not be enough though, as this will almost certainly put the drive axles overweight. But, by moving 2t worth of battery packs in this circumstance from the tractor to the trailer, you can match the standard payload capacity of a diesel truck and standard trailer, without going over any current axle limits. Where the biggest benefits may lie is if we can put the major proportion of the battery power unit into the trailer, making the motive units consideraby lighter. But this will need a full rethink on many things such as the axle distribution and the positioning of the fifth wheel to keep those axle weights within regs.
So let’s consider a made up, but quite close to reality scenario as to how this type of equipment could work. Imagine some of the UK‘s largest transport operators, who are also grocery retailers, as they tend to be. Let’s take a fictional one, and in this case, we will call them ‘Tesburys’.
When a Tesbury’s truck departs its home DC for a store delivery, it may go quite a considerable distance perhaps visiting a couple of stores and perhaps an another DC or supplier to collect a back-load on its return. When that trailer is brought back to its base distribution centre it will usually be parked on a bay and the motive unit unhitched and taken to perform another route. In many cases, that trailer may be kept on site either being loaded at a dock, or parked in a trailer bay for a number of hours until it is ready to be taken out by another tractor unit again. It is those hours where the trailer resides at the DC, that we see as the ‘golden window’ to charge that equipment. If an operator can take that time to plug the trailer in whilst it is both on a bay or in a trailer park, when those trailers are subsequently ready to roll, they are suitably charged and ready to provide power to the motive unit.
Of course there will be times when the entire unit including the motive unit and the trailer can be charged and it is surely not beyond the wit of man to be able to design a charging solution that would work in both ways between each part of the vehicle in that case. We may then finally see the long-awaited rise in solar panel roofed trailers to add a free live charge to the kit, or the ability to power refrigeration, tail lifts or movable floors from the same battery packs.
Of course this example will not work for everyone, but it will work for some, and for those it would work for this my account for a significant proportion of UK LGV Road traffic. Many operators may operate tractor to trailer ratio of 1:2 or more. In that circumstance we could easily argue that trailers could spend on average at least 12 hours a day at base or parked up in a position where they could be charged.
We know that there are operators out there such as Krone / Trailer Dynamics looking at e-trailers as a concept, but our view is that this is too focused on providing a solution for all vehicle types, not just EV LGV. These developments, whilst excellent and innovative in their own right will not address the root issue about providing the majority of the motive power for the electrified LGV. Perhaps this is a symptom of where the trailer manufacturers are looking at this in isolation from the motive unit manufacturers?
We believe that we need to look at all manner of challenges differently to enable our operators and economies to migrate to a greener future. Simply trying to design new types of equipment to mould them to fit existing practices and processes will not yield the step change in performance and activity, and most importantly uptake of the technology that we need to see.
We call upon our fellow logisticians, truck manufacturers, business and government leaders and other experts to get their heads together to say how else can we approach the challenge our operations face as we move towards a zero-carbon economy.
For us, all we ask is that you remember this EV truck is in motion and it is only going in one direction.
About the Author:
Craig Willoughby has been in the transport & logistics industry since the early 90s, holding a number of senior operational and executive positions. He has been a strong advocate for sustainable transportation innovation since first leading a trial on the use of Solar-Panelled trailers in 1995 for his then employer, Sainsburys. He has since worked all over the UK and the World helping businesses achieve great supply chain cost and sustainability solutions. You can read more about Craig here.
About ASCALi:
ASCALi is a leading Supply Chain & Logistics Consultancy, focused on helping businesses of all sizes streamline their supply chain operations. To read more about how ASCALi can help you optimise your transport solutions, please click here, or why not review some of our consulting team’s successes via our case studies page.
