The availability of electric heavy-duty vehicle (HDV) models continues to expand across all leading global markets.1 According to the “beachhead model” of zero emissions HDV adoption, market expansion in heavy-duty segments and duty cycles where economics and supportive policy have already given EVs a strong basis for market growth, such as transit buses, can help to build manufacturing capacity, supply chains and technology transfer of key components of electric powertrains for subsequent waves of electrification. Initial deployment of HDVs in such applications can also build confidence in and familiarity with the faster charging needs and grid capacity which subsequent, HDV duty cycles depend.

The first step in EV adoption in the HDV segment will be successful deployment and proof of economic benefits and societal benefits (e.g. reduced noise and air pollution) in early applications. Subsequent roll out will build upon the operational experience, technology advances and infrastructure to deploy zero emissions HDVs in return-to-base operations such as urban delivery vans, shuttle and school buses, and garbage trucks. The aim is to make even longer distance applications with higher overall daily energy storage needs, such as regional and long-haul freight, competitive and convenient, and to increase their payloads as well as their flexibility and autonomy of operations. Commercialisation patterns of HDVs by segment clearly illustrate the progress across typical stages of technology development. They also show the steadily increasing range of models available in each segment.

Charging strategies for HDVs

Depot charging, which keeps costs down by charging (often overnight) at slow but sufficient speeds, is the common method used for commercial vehicles, regardless of duty cycle and application. Provision of high speed opportunity charging along routes may be necessary for applications with longer but regular routes or predictable operations, such as shuttles and public transit or school buses. Applications with highly variable routes, like urban delivery vans, may also benefit from charging on publicly available chargers in cities, e.g. while drivers take a break.

Very fast charging on highways will be needed to provide flexibility and autonomy for regional and long-haul electric trucks. Given the high construction and grid integration costs, the business case for very fast charging infrastructure of more than 350 kilowatts (kW), or even more than 1 megawatt (MW), may be uncertain, especially in the initial years of electric HDV market deployment. This uncertainty coupled with long lead times and investment requirements needed for HDV megawatt charging capacity along transport corridors are challenges. Policies and measures to support the development of charging networks, may have an important influence in the timely roll out of charging infrastructure for EVs including HDVs. Strategic planning is required to optimise the design and development to be compatible with HDV operational needs. Co‑ordinated roll out will need to focus first on the most heavily used freight corridors.

Other options to provide power to electric HDVs are battery swapping and electric road systems. Pilot programmes for battery swapping are underway by various companies in China, e.g. CATL, Foton New Energy Vehicle, Geely, China Energy Investment Corporation and Qiyuan Motive Power. These trials include battery swapping operations for fleets numbering from tens to low hundreds in heavy-duty short-distance operations such as urban and regional delivery. A central government direction to pilot battery swapping across eight cities include three that aim to focus on swapping for HDVs and the ambition to scale up the number of trucks using battery swapping into the thousands in the coming few years. By early 2022, 159 new truck models on the Chinese market have battery swapping capabilities.

Electric road systems can transfer power to a truck either via inductive coils2 in a road, or through conductive connections between the vehicle and road, or via catenary (overhead) lines. Catenary and other dynamic charging options may be promising from the perspective of competing favourably in terms of total capital and operating costs This is in comparison, with very fast highway charging in which the key determinants of competitiveness are the costs and capacities of batteries for HDVs and the volume of freight traffic. By enabling charging-on-the-move, catenary systems could support operational flexibility of logistics operators.

Field trials of catenary systems installed by Siemens with Scania trucks have been used in real transport operations on motorways since 2016. Currently three systems of 13 km length are used by 15 trucks. Germany has announced innovation clusters that aim to roll out hundreds of kilometres of motorway equipped with catenaries, used in combination with stationary charging and refuelling. The United Kingdom aims to trial a catenary system for heavy-duty trucks. A few European countries, e.g. France and the Netherlands, have commissioned studies on the economic viability and environmental impacts of electric road systems. Catenary or other dynamic charging solutions also have the advantage of functioning on any zero emissions powertrain system (i.e. PHEV, BEV or FCEV) equipped with a pantograph or other on-board power transfer components.