Project Details


trolley:2.0 - Trolley Systems for Smart Cities was an Electric Mobility Europe project aiming to prove that battery-supported trolleybuses are a way forward towards electric public transport systems in European cities.


Project details

Duration 04/2018 – 09/2020


Coordinator trolley:motion

Project goal

Trolley bus systems provide modern zero-emission public transport for urban areas, however, lack the flexibility that battery-equipped electric buses provide. trolley:2.0 brought the advantages of both systems together, developing trolleybuses further into hybrid-trolleybuses that allow for the partial off-wire operation while making more efficient use of the trolleybus catenaries to charge the batteries in-motion. The 9 trolley:2.0 partners from public transport, industry and research aimed to prove that battery-supported trolleybuses are a way forward towards electric public transport systems in European cities by demonstrating the new charging concept in-motion charging (IMC), that allows for the partial off-wire operation of hybrid-trolleybuses in remote sections of the networks. The trolley:2.0 use cases were located in four cities with existing trolleybus systems from different EU-countries, Szeged (HU), Arnhem (NL), Gdynia (PL) and Eberswalde (DE). These demonstrations were evaluated and new innovations for smart trolley grids were demonstrated, e.g. automated wiring technology, smart trolley grid management, the usage of renewable energy sources, energy storage concepts and multi-purpose charging stations based on existing DC infrastructure from trolley networks.


trolley:2.0 demonstrated successfully how to reduce cost-intensive infrastructure elements of trolleybus networks without decreasing reliability and performance.

The project partners demonstrated several technology items which – taken together – could be considered as a future smart trolley network, and as a backbone for zero-emission mobility systems in urban areas.

In the four project cities Eberswalde (DE), Szeged (HU), Gdynia (PL) and Arnhem (NL), trolley:2.0 partners collected new findings on the possibilities of battery electric trolley buses and smart trolley networks. In Arnhem, the trolleybuses can operate autonomously for at least ten kilometres, thus ensuring local zero-emission public transport also outside of the city. In the future, it is planned that only battery-electric trolleybuses will be used throughout Arnhem's city transport system. The sections without overhead contact line will be battery electric. A 350 kw DC charger prototype was demonstrated by a TROLLEY 2.0 partner, which will subsequently be tested and integrated into the trolley networks in Arnhem. This enables hybrid trolleybuses to charge the battery for a few minutes at terminus stations and ensure safe circulation. In addition, an analysis was performed about the potential for the integration of renewable energy from PV and wind power into trolleybus networks, to create a true zero-emission public transport system.

Completely local emission-free travel is already possible in Eberswalde’s city area, after project partner BBG Eberswalde (Germany) converted its buses with lithium-ion batteries. BBG converted a diesel-powered regional bus line into a battery electric trolleybus line.

The Polish city of Gdynia worked on expanding trolleybus lines throughout the metropolitan region. The studies and analyses focused on the one hand on existing routes on which diesel buses are to be replaced by trolley and electric buses. And on the other hand on new trolleybus lines, which are to run on parts of the route without overhead lines. Based on extended CBA tool analysis, routes have been identified and recommended to the associated partner City of Gdynia. In addition, a study was conducted on the possibilities of Stationary Energy Storage (SES) systems including the use of 2nd life batteries.

In Szeged, the economic efficiency of the systems shall be increased by the development and preparation for the use of new midi trolleybus types (8m) based on batteries. The first midi-battery trolleybus tested in Szeged and shall eventually operate on the 77A line in Szeged, where it will run for 30 km with up to 20 km without overhead line. The bus will benefit from a weight reduction of 20 percent owed to the composite frame, which also acts as an insulating material. "

Role of Rupprecht Consult

We supported the global trolleybus association trolley:motion in the management of the project and in the development of business cases and policy recommendations for the further advancement of trolley-hybrid systems.

Project partners