A cleaner city: electric buses in Vienna (Austria)

By News Editor / Updated: 08 Apr 2015
The Wiener Linien (a Vienna-based public transit company) has purchased 12 innovative electric microbuses that can recharge using overhead power lines for trams. The technology is specially designed for this project and currently 12 buses are fully operational on a daily basis. The buses charge over night at a depot, and during daytime operations stop at existing tram stations to recharge. To connect to the existing infrastructure, the buses use a pantograph located on the roof of the bus. Replacing the existing liquefied petroleum gas buses with electric buses has reduced carbon dioxide emissions in Vienna by 300 tons.
Vienna is the capital of Austria and has around 1.75 million citizens. Different public transport modes are available, including a 75km-long metro system with 101 stops, and the fifth-largest tram network in the world with a total length of about 180km and 1 031 stations. In 2009 186.9 million passengers used the network's trams.
In addition, there is also an extensive bus network. An increasing number of travellers use public transport (up from 19 per cent in 1993 to 29 per cent in 2012) and the overall number of trips has grown to over 900 million, with an increasing share of regular customers (500 000 in 2013). Vienna has a Transport Master plan (2003), which states that the main public transport goal for 2020 is increasing public transport from 34 to 40 per cent. In 2011, the Wiener Linien decided to aim for zero emissions in the city centre.
In action 
The zero-emission ambition of the Wiener Linien meant replacing a number of the buses operating on the inner-city lines with electric buses. It was the start of an intensive procurement phase that resulted in a contract with Siemens/Rampini for 12 vehicles (ElectriCitybuss) in September 2011. The first bus came into operation in September 2012, and the last in June 2013. The Wiener Linien had specific preconditions the buses should meet. This included conditions regarding the use of existing infrastructure (charged via overhead lines or using induction technology), charging times (maximum of 15 minutes), range (minimum of 150km) and minimum carrying capacity (30 passengers).  

Initially there were four bus suppliers that participated in the testing phase. The buses were tested for one week: only two met the minimum requirements and only the Siemens/Rampini consortium was able to meet all requirements. The other buses were rejected for various reasons including, for example, having insufficient ranges. One of the buses had the batteries under the bus which was considered dangerous and made the bus less accessible.

The Siemens/Rampini buses use nine lithium-ferrite batteries (with a capacity of 96 Kwh). The buses have two doors and are 7.78 metres long with a range of 150km (without recharging). In the winter the range decreases to 120 km. The buses can carry up to 46 passengers and have full electric heating and cooling systems for the passenger and driver area. During braking the battery is recharged. The buses cost over € 400 000 but prices are expected to come down as production numbers increase. The relevant staff received a short training to learn how to drive the electric buses.
The buses cost around twice as much as conventional models. In addition, modifying the charging infrastructure represented an extra expense - charging points at the depot cost € 320 000 and at the end stations cost € 90 000 each. However, there are also substantial benefits during operation.
The buses are electric, which results in a large reduction in fuel costs and makes the buses 100 per cent emission-free (on location). The electricity the buses use comes from a renewable energy mix (50 per cent water power; 8 per cent photovoltaic; 15 per cent wind and 27 per cent gas). Estimations from the Technical University of Graz show that each electric bus has lower emissions than the conventional bus it replaced: 5.3t less CO2; 1.7t less NO; and 0.06t less NO2 per year. The buses also result in reduced noise and improved public health. Despite all the positive environmental effects, it should be noted that there are also the negative social and environmental effects caused by the production of the lithium-ferrite batteries.
Challenges, opportunities and transferability 
Interestingly, it was not the city of Vienna that decided to implement or stimulate the implementation of electric buses. The public transport provider Wiener Linien took the initiative to help reduce emissions in the city centre of Vienna. The future for this type of electric buses looks bright: currently Siemens/Rampini is actively trying to work with other cities around the world to implement these types of buses. In addition, the Wiener Linien wishes to expand their fleet with 12-metre electric buses in 2016 (the tender will be published in 2015). Now passengers can board the buses during charging, whereas previously they had to wait until the buses were charged. This means that Wiener Linien has capacity to lend a bus to other cities. Recently, a bus was lent to Bremen (Germany), and Brno and Prague (Czech Republic) - but in principle the technology is interesting for all cities that have an existing tram infrastructure.

The main challenges for the future are:

  1. Increasing the battery lifetime  (to 4-5 years);
  2. Reducing the price of the buses (which is still high compared to conventionally fuelled buses).
Collective passenger transport
Clean and energy-efficient vehicles
Peter Wiesinger
Jan-Willem Van Der Pas
PDF icon Clean Fleets project case study350.47 KB
27 Feb 2014
08 Apr 2015