Project Completion SPIRIT-E: How Electric Trucks Can Serve as Power Banks

Electric trucks can not only charge electricity but also store it and release it selectively—like a power bank on wheels. This is what the SPIRIT-E project has shown after three years of operation. The consortium presented the results of their joint work at a public online conclusion event.

Image: MAN

SPIRIT-E ran from August 2023 to October 2026. This research project, funded by the federal government and supported by DLR, was initiated to identify existing barriers to the electrification of heavy transport and develop practical solutions. On one hand, the project team adopted an approach of making private charging infrastructure at logistics locations available to third parties and creating reservation options for it (a practice that is already widely used today). On the other hand, SPIRIT-E explored how bidirectional charging and reservable private charging infrastructure could be integrated into existing energy systems to promote sector coupling between the energy and transportation sectors.

Shell Business Recharge Solutions (SBRS), a company within the Shell group, developed the corresponding bidirectional DC charging infrastructure for this project, thereby establishing the technical foundation for all Vehicle-to-X applications. The consortium also included the TU Munich as lead partner, along with Fraunhofer IEE, the Research Institute for Energy Economics, TenneT, Hubject, Consolinno Energy, and MAN Truck & Bus.

The solutions were tested in a real laboratory at the Schmid logistics company in Obertraublingen near Regensburg. There, the project team also carried out the world’s first Bidi charging process for an electric truck via a live demonstration in the spring. It was a major event even for us: electrive broadcast the demonstration on April 24 as a live stream. You can view the recording here. The main player was a MAN eTGX with a usable battery capacity of 480 kilowatt-hours. Through the bidirectional DC charging station from SBRS, this truck fed power back at a rate of up to 350 kilowatts.

Image: Peter Schwierz

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After three years of the project, TU Munich concludes that electric trucks could offer ways to reduce energy costs and ease financial pressure on freight companies: “Their batteries can also be used as energy storage for warehouses or the public grid.” The university played a key role in conducting research supporting the project.

Part of SPIRIT-E also involved integrating these mobile batteries into the electricity market: In a specially created testing environment, project partners explored how these vehicles could store energy when prices are low and sell it back when prices are higher. “This could allow freight companies to generate additional income in the future,” explains TUM.

To make this work, the consortium developed and tested the necessary interfaces between trucks, charging stations, energy management systems, electricity suppliers, and grid operators, including a reservation system for charging stations.

Basically, the project participants tested three different Bidi applications: the truck supplied electricity to other vehicles (Vehicle-to-Vehicle), supported power supply to the facility premises (Vehicle-to-Site), and fed energy into the public grid (Vehicle-to-Grid). Communication between the vehicle and charging infrastructure was based on the international standard ISO 15118-20.

The TUM Chair of Vehicle Technology investigated in its accompanying research primarily whether and how freight companies can operate their fleets reliably on electricity and how cost-effective such a transition can be. According to the university, the basis for this research included real driving data from six German heavy-duty fleets with a total of 2.15 million recorded kilometers. The key findings are summarized briefly here:

• Reserving charging stations: If electric trucks can reserve public charging stations in advance for long-distance trips, planning certainty increases. The time loss compared to diesel trucks decreases to around 1 to 4 percent on average, depending on the scenario.

Plan fleet and depot together: With its own charging infrastructure at the depot, a significantly larger portion of the fleet can be reliably powered electrically than using only public charging. Incorporating photovoltaic systems and battery storage further reduces costs by 25 to 44 percent compared to a simple conversion of trucks.

Rethink route planning: By including flexibility in charging into route planning, charging can be scheduled during favorable times. This helps reduce the overall costs of the fleet depending on the nature of orders.

Intelligently integrate the depot into the energy system: Smart integration into the power grid and electricity market reduced the overall costs of the studied fleets by an average of 1.7 cents per kilometer. With bidirectional charging, this figure reached 6.1 cents per kilometer.

According to TUM, the most promising approach is using the stored electricity at the same location. “For example, electric trucks can absorb excess electricity from a photovoltaic system during the day and release it later. This helps increase self-sufficiency. The vehicles can also meet high electricity demands in the short term, thereby avoiding costly peak loads,” emphasize the scientists.

The project team considers a potential savings of around ten percent on energy costs to be realistic. “With 100,000 kilometers of annual driving distance, this corresponds mathematically to the energy costs of driving 10,000 kilometers,” they say. The extent to which a logistics company benefits depends mainly on driving distance, downtime, and electricity prices. Vehicles used in regional transportation that regularly return to the depot are particularly suitable for this approach.

At the closing event, the project team emphasized that the biggest hurdles now lie less in technical implementation and more in integration into the power grid and economic conditions. For example, the existing grid connection capacity at many depots is insufficient for charging larger fleets of electric trucks. “Flexible grid connection contracts, battery storage, or shared charging infrastructure can help overcome these limitations,” was the unanimous opinion.

However, there are still no unified standards for marketing the stored electricity. Many providers use their own technical solutions that are not compatible with each other. Additionally, according to the project participants, it is necessary to clarify how tasks and revenues will be distributed among freight companies, vehicle manufacturers, and electricity marketers.

"SPIRIT-E has shown that heavy electric trucks can be much more than just new electricity consumers. Technically, they can be integrated into the energy system as flexible storage solutions. Now it’s necessary to standardize these proven solutions, scale them up, and transform them into viable business models — for this, research, utility operators, industry, logistics, and policymakers must work together," summarizes Prof. Markus Lienkamp, head of the Vehicle Technology Department at the TUM School of Engineering and Design.