Siemens Worldwide

Pictures of the Future



Mr. Sebastian Webel
Mr. Sebastian Webel


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Pictures of the Future
The Magazine for Research and Innovation


Electric Future for Hamburg’s Buses

New charging technology from Siemens enables e-buses from different manufactures to use the same charging stations. Siemens is the first supplier worldwide to provide a charging infrastructure that enables interoperability.

Fast-charging stations from Siemens are being used to recharge electric buses from various manufacturers several times a day in Hamburg. This is bringing the city a major step forward toward zero-emission local public transport.

Bus No. 109 in Hamburg is a traveling preview of the future. The city’s public transport operator, Hamburger Hochbahn, is using the line that runs from the idyllic Alsterdorf district in the north to Hamburg Central Station to test buses with innovative drive systems in everyday operation. The buses being tested here include hybrid models from Volvo. The buses’ batteries are recharged at the final stops on each end of the 9.3-kilometer route. Each of the charging stations has two masts equipped with a top-down pantograph that recharges the batteries in just six minutes.

The Hamburg fast-charging stations, which were developed by Siemens Mobility, previously could only be used with Volvo buses, which meant other manufacturers that also offer electric buses were left out in the cold, thus limiting the city’s planning possibilities. All of that changed in mid-August 2016, when HPC (high power charger) masts from Siemens with a capacity of 300 kilowatts also began charging three battery-powered buses from Polish bus manufacturer Solaris.

Battery-powered buses built by Solaris will be charged at the same Siemens charging stations that power plug-in hybrid buses from Volvo.

This marked a world premiere, as the Siemens charging system is now capable of charging electric and electric-hybrid buses from different manufacturers. This means that other local public transport pioneers, such as Göteborg and Stockholm, will now be able to use electric buses from different manufacturers rather than just from one – and without having to retrofit their infrastructures.

Since they offer zero-emission and low-noise operation, electric buses are expected to play an important role in urban transport planning.

Toward Cleaner, Quieter Urban Environments

This development makes sense, as more and more people are now using buses, trains, and local rail systems. According to the German Federal Statistical Office, 11 billion trips were taken on public transport systems in Germany alone in 2015, which is more than ever before – and the numbers continue to increase. Such figures make it clear that environmentally sound and climate-friendly public transport is becoming increasingly important. Efforts to improve the situation in Hamburg focus on buses because most buses today still run on combustion engines.

Electric buses therefore play a key role in public transport planning in cities. They not only offer zero-emission and low-noise operation, better environmental compatibility, and better quality of life for urban residents; they are also more energy efficient and generally require less maintenance because they have fewer mechanical drive system components. Their attractiveness is also increasing in line with the development of intelligent charging systems such as those from Siemens that enable dependable operations.

Topping up a bus’s charge during its final stops at each end of a route expands its range by guaranteeing that it will be able to reach the next charging station without delays. Moreover, quick charging times allow bus operators to maintain service in short intervals where needed. An additional benefit is offered by the fact that a charging station basically consists only of the mast and a small transformer building. Electric buses also require very little equipment. “The buses that use Siemens’ fast-charging technology only need to have contact rails and a WiFi communication unit;” explains Stefan Guggenberger, Head of Electric Buses at Siemens. “That means more space and less weight and complexity.”

Flexible Charging

The charging process itself works as follows: A bus arrives at a charging station and drives underneath a current collector (pantograph). A WiFi system simultaneously establishes a connection between the bus and the charging station. The pantograph is lowered onto the contact rails on top of the bus and begins the charging process. The bus’s batterys charge level and condition are continually displayed on a screen on the bus driver’s dashboard. The driver can end the charging process at any time. Whenever this occurs , the HPC fast-charging system reduces the current and opens the charging circuit. The pantograph is then raised and the bus can leave the charging station.

The Hamburg state government (Senate) has set itself the ambitious goal of procuring only zero-emission buses beginning by 2020. Thanks to the flexible electric charging stations from Siemens and Bus No. 109, an electric bus future for Hamburg is now one step closer to becoming a reality.

Hubertus Breuer