An electrifying proposition

Professor Phil Greening, Deputy Director of the Centre for Sustainable Road Freight and professor at Heriot-Watt University, considers the challenges and the options for future vehicle fleets in a zero carbon world. 

Taken from Panmure Perspectives Issue Four: The UK government has committed in law to reducing CO2 emissions by 80% by 2050 compared to 1990 levels. Recently, many have reached the conclusion that this reduction is not enough, and that the UK must commit to net zero carbon emissions by 2050.

While there are many areas of economic activity that contribute to CO2 emissions, the biggest contribution is made by transport. This sets the context for the government’s latest initiative ‘Road to Zero’, which outlines potential pathways to net zero emissions from road freight.

Road freight can be differentiated from passenger cars because it involves a driver who is usually paid, and furthermore, it is concerned with moving large weights or volumes over long distances. This makes road freight an energy intensive business, and for the last 100 years, the overwhelming majority of road freight vehicles have been powered by diesel internal combustion engines. Although diesel has an attractive energy density, it also generates large volumes of CO2, and is, as such, not suitable for our future needs as a decarbonised society.

Logistics operations are currently constrained by time (both in terms of the load leaving the warehouse and the preferred customer delivery time), the need to minimise inventory in the supply chain, and vehicle capacity. When considered together, these constraints provide a context for the planning of transport and warehouse operations; these limitations will change when vehicle charging times and reduced vehicle range are subsequently considered.

Electricity peaks
Despite this, electrification is generally accepted as the long-term solution for the decarbonisation of road transport; this is because clean electricity generation is the cornerstone of decarbonising a wide range of economic activities such as manufacturing, the service sector, and even domestic buildings.
This presents two new challenges: firstly, the use of electricity in new applications, such as transport, will generate increased demand. However, the current demand for electricity is defined by peaks that are multiples of average demand, occurring in the morning and in the evening. During the rest of the day there is surplus generating capacity which could be deployed to provide electricity for transport.

New substations
Secondly, the demand for transport electricity is also likely to occur in the morning and evening periods, requiring us to find ways of storing energy on vehicles so that we do not need to greatly increase electricity generating capacity. This forces us to consider the operational implications of electrifying road transport, and in particular the infrastructure requirements for charging large volumes of vehicles in short periods at centralised locations such as warehouses. This is not trivial: charging a fleet of 50 articulated trucks from an existing warehouse supply will not be possible without significant reinforcement of the electricity distribution network, in particular the building of new substations.

In short, the need to electrify road freight will require new vehicle designs that incorporate
energy storage, which will require trade-offs between vehicle payload and the weight of batteries or other energy storage solutions. In any event, the development of suitable charging infrastructure presents a significant challenge. The cost of an electric freight vehicle is currently around double that of its diesel equivalent, and while the energy costs associated with electrification are considerably less than those associated with diesel, the energy costs of operating a diesel freight vehicle are only about 20% of the overall operating costs, because the driver accounts for approximately 60% of these costs. In broad terms, there is no economic case to move road freight to electric vehicles, and therefore in the absence of government regulation and policy we can anticipate low adoption rates for electric freight vehicles. This will not address the environmental imperative.

However, this narrative can be reshaped if we consider the opportunity of autonomous vehicles and their impact on cost structures. By removing the cost of the driver, we decrease the operational costs of freight vehicles, but if that vehicle is electric we increase its capital costs; over a seven-year life, the total cost of ownership will approximate to that of a current diesel truck.

In essence, the lowest cost way of delivering the UK government’s ‘Road to Zero’ is to accelerate the development of autonomous electric freight vehicles. This will drive a revolution in material handling concepts, particularly in those parts of the supply chain closest to the consumer that currently rely on the driver to provide the means of loading and unloading the vehicle.

Electrification of road freight presents many challenges but offers the elixir of decarbonisation, and a new competitive landscape in which some organisations will adapt to thrive and others will fall short.