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sts.components.contact.mr.placeholder Sebastian Webel
Mr. Sebastian Webel

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Pictures of the Future
The Magazine for Research and Innovation
 

Electric Mobility

Electric Buses: Rapid Charging in Vienna

Europe’s first fleet of electric buses is now operating emission-free in Vienna, Austria.

Siemens is accelerating the pace of the energy transition in Austria’s public transport sector with two projects. One involves Europe’s first fleet of mass-produced, quick-charge, fully electric buses. The second is a joint venture that will make electricity an appealing alternative to gasoline for vehicle owners.

The western part of Vienna, Austria is a traditional working class and industrial district. It’s also the site of one of three bus depots operated by Wiener Linien, the company that runs much of the city’s public transit system. The fueling stations behind the depot don’t conjure up images of new drive system concepts for public transport. Nevertheless, the facility is essentially a docking station for the first of a total of 12 electric buses (eBuses) that can recharge their batteries from overhead power lines.

Vienna has two downtown bus lines that have been running exclusively on electricity since summer 2013. The conversion of the inner-city lines, which previously operated with liquefied gas drives, is part of “a large-scale city government project that will further expand and fund the public transport system,” says Anna Reich, press spokeswoman for the Wiener Linien public transport company.

Fast Charging

“Our goal is to encourage more people to travel through the city in an environmentally friendly way,” adds Reich. In July 2012, the company tested several different bus models, including one from a Czech manufacturer and a solar bus produced by an Austrian company. However, it was a regular service bus built by Siemens in cooperation with Rampini that came out on top. Rampini is an Italian company that has been active in the electric bus sector for quite some time.

As Reich explains, Wiener Linien was particularly impressed by the rapid charging concept developed for the new bus. Vehicles from rival bidders required a much larger number of batteries, which reduced space for passengers, or were impractical due to their use of solar energy. The Siemens-Rampini bus, on the other hand, gets its energy from the extensive DC power grid for trams and subway trains. The buses’ lithium-ferrite batteries — one of the most efficient battery technologies available today — are slowly recharged to full capacity overnight.

During the day, the eBuses are connected to the tram grid, allowing them to recharge their batteries in 10 to 15 minutes. This can as much as double the service life of their batteries because frequent recharging means they are never fully discharged. Due to the combination of an exhaust-free drive system and a level of integration in the public transport network that is unique in Europe, the new bus received the EBUS Award from the €œForum für Verkehr und Logistik€ transport association in October 2012.

Integrated Charging System

“It drives like a normal bus,” he says as he opens the driver’s cab. Indeed, everything looks normal at first glance — for example, there’s a brake and a “gas” pedal. But once the bus moves, you notice that it isn’t loud but instead seems to hum in a pleasant way. It also accelerates smoothly and comes to a stop very comfortably thanks to its electric brakes. Hauswirth says most passengers reacted positively to the eBus during his test trips, especially “older people, whose interest in the technology surprised me.”

The bus’s technical wizardry is concealed inside. For instance, its three-phase, 85-kilowatt AC motor from Siemens also acts as a generator. Specifically, the braking energy that would normally be wasted as heat is directly fed back into the batteries. Josef Hofbauer, a project manager at Siemens, and Johann Hauswirth, the Wiener Linien technician responsible for the eBus project, are happy to show off the two red and white buses in the garage. The sides of the buses are adorned with the Wiener Linien logo, next to which “electriCity Bus” is prominently displayed. Hauswirth was one of the first people to drive an eBus in regular service operations.

There’s really nothing new about this. However, the eBus is special because, unlike most other manufacturers’ buses, it does not use a diesel engine to generate energy — in other words, it isn’t a hybrid. Hofbauer says the only vehicle comparable to the eBus in Vienna is manufactured by the Chinese company Build Your Dreams. But Siemens’ integrated charging technology gives the eBus the edge. “There’s nothing in the world that’s similar; our vehicle is unique in the bus sector.”

The electric motor, of course, is by no means a new development. Back in 1909, a battery-powered bus shuttled Siemens employees and customers between the Vienna Opera and Siemens’ headquarters. However, poor power storage worked against it. Electric mobility never really came into its own until recently — in the 21st century.

"There’s nothing in the world that’s similar; our vehicle is unique in the bus sector."

That’s why Siemens joined 34 other companies to create the Austrian Mobile Power platform, which has launched many different types of research and development projects. Close cooperation with Austria’s leading power utility, VERBUND, also led to the establishment of the E-Mobility-Provider Austria — a joint venture between Siemens and VERBUND, which began operating in October 2012. The company wants to build a nationwide network of roughly 4,500 (semi-)public charging stations by 2020.

The plan is to acquire commercial customers with electric vehicle fleets in 2013. Afterward, the charging service will be extended to broad sections of the population. The e-mobility provider also wants to put together a reasonably priced and therefore attractive overall package consisting of a comprehensive charging network, a charging box for home use, and service and roadside assistance. Customers will also be given a “normal” car with a combustion engine once a year to take on a vacation.  

Another eBus is now being put through its paces in the Wiener Linien garage. The bus will soon be approved by city authorities and will then begin regular service operations. At a later stage, the inner-city lines will be converted to handle fully electric full-size buses.

Florian Falzeder