MAN eTGX with 480 kWh Becomes a Power Bank on Wheels: First Real Test of Bidirectional Charging for Heavy Trucks
MAN Truck & Bus has demonstrated bidirectional charging of a heavy electric truck for the first time under real conditions. The event took place at the Schmid shipping company's premises in Obertraubling, near Regensburg, as part of the SPIRIT-E research project, featuring a MAN eTGX equipped with 480 kWh of usable battery capacity. The truck not only absorbs energy from the grid but can also send it back to the depot, to other fleet vehicles, or to the public grid itself, thus transforming into a high-capacity mobile accumulator.
V2V, V2S, and V2G: The Three Modes in Action
SPIRIT-E has validated three distinct operational scenarios. With Vehicle-to-Site (V2S), the energy stored in the eTGX directly powers the depot facilities, reducing peak loads and maximizing self-consumption from photovoltaics. Vehicle-to-Vehicle (V2V) allows a truck with a full battery to transfer energy to another waiting fleet vehicle, consequently reducing downtime. Vehicle-to-Grid (V2G), on the other hand, pushes the concept beyond the depot's boundaries: the truck supplies electricity to the public grid during high demand or high price periods, with potential additional revenue streams for fleet operators.
According to consortium calculations, intelligent energy management can reduce electricity costs by between 10 and 20 percent. The advantage is particularly significant for regional transport operators with annual mileage below 100,000 km: in this range, trucks stay at the depot for long enough periods to make the charging and discharging cycle economically viable. As mentioned in the press release, the goal of SPIRIT-E is to demonstrate that heavy trucks can become active elements in the energy system, no longer mere passive consumers.
SPIRIT-E is funded by the German Federal Ministry for Economic Affairs and Climate Action and brings together expertise from across the supply chain:
- Technische Universität München (TUM) as the lead,
- Fraunhofer IEE,
- FfE (Research Center for Energy Economics),
- SBRS (Shell Business Recharge Solutions),
- TenneT,
- Hubject,
- Consolinno Energy, and
- MAN Truck & Bus.
The resulting combination of expertise covers vehicle technology, energy management, charging infrastructure, energy market, and real operations within a logistics context. It is one of the most comprehensive approaches to V2G for heavy vehicles so far, an area that is already seeing initial commercial rollouts for passenger cars.
Georg Grüneißl, Head of Product Strategy at MAN Truck & Bus, summarized the result as follows:
"Our eTrucks are effectively becoming power banks on wheels, capable of reducing energy costs while strengthening the electrical system as a whole. SPIRIT-E has demonstrated the concrete potential of this technology and how electric trucks can actively contribute to the energy transition."
Outlook Towards Commercialization
V2G for heavy trucks is still in the validation phase at a real scale, but the demonstration in Obertraubling has shown that the technological foundations hold under authentic operating conditions. By the end of the decade, with the growth of the flexibility services market and the integration between logistics and energy management, V2G is expected to become a profitable business model for fleet operators. The critical bottleneck remains the regulatory framework: in many European markets, the remuneration for energy fed back into the grid by commercial vehicles still lacks clear rules, hindering widespread adoption even where the technology is ready.