Heavy trucks need supercharging
MAN
Just a few moments ago, Hubert Aiwanger, Bavaria's State Minister of Economic Affairs, Regional Development and Energy, plugged a heavy goods vehicle (HGV) into the mains power supply. With this simple act, the first demonstration of the NEFTON research project's Megawatt Charging System began – in front of an audience of 200 guests from the worlds of politics, science, business and media. Next to the vehicle itself, a display shows the charging rate. The cable connecting the truck to the charging station is as thick as an arm and must be constantly cooled. After all, in just three hours, it transmits roughly as much electricity as a three-person household consumes in an entire year. This huge capacity means the large battery in an electric semi-truck (also known as an articulated lorry) can be charged in under 30 minutes – a significant milestone in the quest for climate-neutral freight transport by road.
Climate transition held up in traffic
While greenhouse gas emissions are steadily falling in the energy and industrial sectors, transport remains a problem. In Germany, the transport sector accounts for approximately one-fifth of emissions. Although electric cars are gradually becoming a common sight on the roads, electric HGVs – or e-trucks – are still rare. Yet the commercial vehicle sector is precisely where a switch to greener power could deliver the greatest benefits. A single semi-truck, on average, churns out as much greenhouse gas in one year as 50 cars. In total, heavy-duty vehicles are responsible for more than five percent of Germany's total greenhouse gas emissions. If large trucks on German roads are electrified, half of freight transport emissions could be eliminated.
Most passenger and freight trains in Germany already run on renewable electricity. However, quickly shifting a significant portion of freight from road to rail is only possible to a limited extent, due to a lack of capacity in the rail network. To make freight transport more climate-compatible in the short term and to achieve the national climate goals set for 2030 and 2040, the focus must therefore be on approaches that directly address road freight transport.
Electric trucks are ready to go
The good news: At the IAA Transportation 2024, the most important trade fair for commercial vehicles, all major manufacturers showcased electric semi-trucks with a range of approximately 500 kilometres. The hefty batteries installed in these vehicles store enough energy to haul even large trailers long distances across Europe.
Only one problem remains unsolved: it takes too long to charge these giant batteries. To make e-trucks practical on a large scale, a substantial recharge must be achievable during a driver's 45-minute rest break – and standard charging stations can't deliver that. That's why researchers in projects like NEFTON are developing faster charging systems – and their results are promising.
The Megawatt Charging System
The Megawatt Charging System (MCS) is a new direct-current (DC) charging standard specifically tailored to trucks and other heavy-duty commercial vehicles. Under development since 2018, MCS is designed to deliver up to ten times the charging capacity (3.75 megawatts) of a conventional electric vehicle fast charger. The waste heat generated by electrical currents, which can reach up to 3000 amps, is dissipated via large, actively cooled DC contacts and cables. The first production vehicles and charging stations equipped with MCS are expected to be launched later this year.
The charging technology race
With its Elektro-Mobil (Electric Mobility) programme, Germany’s Federal Ministry for Economic Affairs and Climate Action is funding the most promising charging technology solutions. DLR Projektträger is coordinating the programme, moderating the race to develop market-ready technologies and supporting researchers in funded collaborative projects. These include wireless inductive charging systems, overhead lines and bidirectional charging technologies. In bidirectional systems, electric cars and trucks can not only draw power from the grid but also feed it back – transforming them into mobile energy storage units. This technology could allow fleet operators and haulage companies to generate income even from parked vehicles. The greatest hopes, however, rest on two other charging technologies: the Megawatt Charging System (MCS) and swappable batteries. Through the NEFTON collaborative project, MAN, the Technical University of Munich and five other collaborators have been working on the Megawatt Charging System, which was unveiled to the public last summer.
Vehicle manufacturers prefer cable-based charging systems like the MCS. Indeed, one current objective of the Elektro-Mobil funding programme is to identify technologies that can complement cable-based fast charging and allow for synergies between them. That's because there is one issue with the Megawatt Charging System: charging parks with dozens of trucks – each drawing some 1000 kilowatts of power at the same time – place a major strain on electricity grids. It may be five years or more until sufficient grid connections can be provided. Even today, Germany lacks thousands of truck parking spaces – and future charging infrastructure will further increase the space required for parked semi-trucks.
If fleet operators store and sell selfgenerated solar power from their own warehouse rooftops, or trade energy on the electricity market, this can reduce the total cost of e-trucks and make the power grid more resilient to disruptions.
Researchers in the eHaul project are working on an alternative that could bypass grid bottlenecks altogether. The research consortium – composed of TU Berlin, Bosch and five other parties – is funded through the Elektro-Mobil programme and receives support from DLR Projektträger. Instead of charging vehicles while stationary, eHaul is developing an automated battery-swapping system that replaces depleted batteries with fully charged ones. This concept has seen major success in China since 2020, where roughly one in two e-trucks is now fitted with swappable batteries – and ever more are obtaining approval to do so. Stefanie Marker, who heads the eHaul research project at TU Berlin, explains: "Fast charging and battery swapping should not be seen as competing options. They can coexist and help pave the way for reliable long-distance electric transport. Ideally, battery-swapping stations will act as a transitional solution until nationwide grid expansion is complete – and remain useful on routes where charging infrastructure is still lacking." However, a swapping system requires additional batteries to be kept on hand, and there is currently no common technical standard.
Nevertheless, one thing is certain: the race to develop the future infrastructure for electric trucks is in full swing. Once the right technology is found, the transformation of freight transport can get under way at full speed.
When will e-trucks conquer the market?
Unlike passenger cars, semi-trucks aren't sold on emotion – they're sold on numbers. Logistics companies, facing tough competition and operating under narrow margins, operate strictly in line with economic logic. As soon as the total cost of purchasing, operating and reselling an e-truck – along with charging infrastructure at their own depots – drops below that of a conventional diesel truck, they will gladly make the switch, provided the charging systems can be integrated smoothly into their operations. For German freight companies, the financial balance could start tipping in favour of e-trucks as early as this year. A typical semi-truck covers approximately 600 to 800 kilometres a day. In eight years, it will have travelled about one million kilometres, and reached the end of its useful life. Freight operators renew their fleet based on this cycle, so once e-trucks gain the cost advantage, Germany's commercial vehicle fleet could be fully electrified within a decade.
An article by Jens Erler and Lovis Krüger from the DLRmagazine 177