Development of electro-mobility and introduction of electric mini-buses

Summary

In this measure the City of Brno wanted to increase energy efficiency of electric public transport vehicles, specifically trams and trolleybuses, in order to contribute to better air quality in the city.

Implementing sustainable mobility

The public transport company of Brno (DPMB) operates 150 trolley buses. Operation of clean vehicles requires an infrastructure comprising 28 substations that provide electric energy to the entire trolley bus network. Public transport generally involves frequent braking and accelerating, a very frequent phenomenon due to Brno's hilly topography. Most of the energy generated during the braking process of the vehicle is not used in any way, leading to inefficient operation.

The DPMB expected that the study undertaken by the university to propose a technical solution that involves storing the energy generated during braking and using it for accelerating. Consequently implementation of the measure should consist of reducing peaks in energy consumption of electric public-transport vehicles.

Objectives

• Utilisation of electricity generated by the traction motor while braking
• Reduction of peaks in energy consumption
• Utilisation of the accumulated energy for limited operation of the vehicle without the trolley line
• Reduction in energy efficiency and robustness of public-transport electric vehicle operation

Progress

What has been done?

• The tender for the study
• The study, which was completed in October 2014
• DPMB feedback on the study
• The final version of the study which DPMB received in November 2014
• Recommendation from the study not to implement the technology to the old trolleybuses (not effective and technically problematic)
• Recommendation from the study to install the technology to the new standard 12m long trolleybuses. This type of trolleybuses is expected to be tendered in 2016 after the lifetime of the project.
• Due to the reasons above and in line with the annual review meeting in Malaga the measure was stopped.

What still needs to be done?

• The measure was stopped.

Outcomes

The decision that the DPMB will introduce a new technical solution for clean vehicles which consists of storing the generated energy while braking and using it when accelerating, reducing the peaks in energy consumption in the new fleet of trolleybuses which will be bought in 2016. The other benefit will be that the trolleybus can be driven over a small distance without overhead wires in case of an accident or road works.

The DPMB will measure the amount of energy accumulated and used by electrometers in the vehicles. Measuring will also take place in other public-transport vehicles in order to reduce peaks in energy consumption.