The Arctic Whisper: The World's First Fast-Charged Hybrid Bus Debuts in Umeå, Sweden

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The Arctic Whisper's hybrid bus batteries will be fast charged by the Opbrid Bůsbaar for 5-10 minutes at the end of its route to achieve nearly 100% all-electric operation but with the reliability of diesel. The world's first fast rechargeable hybrid bus is now being tested in Umeå City in a collaboration between the companies Hybricon AB, Opbrid SL, e-Traction BV, Umeå Energi AB and the Umeå City Corporation.

The city's vision is to fill Umeå's streets with a number of these fast-charged hybrid buses by 2014, the year that Umeå will be the “Cultural Capital of Europe”

Umeå, Sweden. Umeå, a city in the far north of Sweden, has just unveiled the world's first fast-charged hybrid bus, the "Arctic Whisper". It combines the no-emission benefits of an electric bus with the reliability of a diesel bus. The Bůsbaar charging station provided by Opbrid SL (Granada, Spain) will be located at one end of the bus route that will fast charge the bus for a few minutes at the end of each trip. This will extend the all-electric range of the e-Traction (Apeldoorn, Holland) hybrid bus from 2 hours to 18 hours. And, since this is a serial hybrid bus with a backup diesel generator, the bus can continue running on bio-diesel in case of brown-outs, traffic jams, or very cold weather.

The City of Umeå, Sweden has found for a solution to electrifying its bus system. Umeå is a university city with many daily bus riders but very cold weather in winter. It has access to large amounts of clean electricity from hydro and wind power. Both diesel fuel and bio-fuels such as ethanol are very expensive in Sweden. Converting the city buses to electricity makes good economic sense, and it supports the city's goal of reducing CO2, noise, and air pollution. Fortunately, the team of Hybricon, Umeå Energi, Opbrid and e-Traction is able to deliver a solution that has the benefits of electric operation with the reliability of diesel.

The city's vision is to fill Umeå's streets with a number of these fast-charged hybrid buses by 2014, the year that Umeå will be the “Cultural Capital of Europe”. Many of the Press conference attendees noted the extraordinary quiet ride of the Arctic Whisper. Since there are no gears or differential, the wheel motors make no perceptible noise.

The e-Traction converted Volvo 7700 is a “battery dominant” hybrid bus. This means that it has the ability to run on battery only, with the diesel generator turned completely off. The Arctic Whisper has 100kWh of Valence Li-Ion batteries, typically enough for 1-3 hours of fully electric operation due to the high efficiency of the e-Traction wheel motors. With the simple addition of the Opbrid Bůsbaar fast charging station, the all-electric operation can be extended to 18 hours.

At the end of the route, the driver pulls up underneath the Opbrid Bůsbaar charging station, and the tram-like pantographs on the bus roof quickly raise up to contact the Bůsbaar. The charging process is completely automatic, with the driver never having to leave the bus. When the batteries are charged, the driver continues on as normal. The batteries are fully charged at night, with the Bůsbaar providing the additional electricity needed for a full day of electric driving.

One of the biggest advantages of this system has other electric bus systems is the backup on-board diesel generator. For example, if there is a power shortage or traffic jam, the bus can switch over automatically to using the backup generator and continue running on bio-diesel indefinitely. This additional source of power gives the system the reliability and confidence of diesel in all weather, traffic, and operating conditions.

An additional interesting detail about this project is that e-Traction and Hybricon were able to convert one of their existing hybrid buses to a fast-charged hybrid in only 6 weeks. The changes that were needed were minimal: they added some additional batteries and the Opbrid pantographs, plus some electrical and software changes to accommodate fast charging. These changes converted a 100% diesel hybrid, to a Fast Charged Hybrid running on nearly 100% electricity, but always with the ability to revert to diesel if necessary.

Testing of the first bus and charging station has begun and will continue through the Spring and Summer of 2011, with a second bus arriving soon.

Advantages of the world's first fast charged hybrid buses:
More efficient - internal combustion engines have only 25-35 percent efficiency while electric motors have up to 90% efficiency
Electric power gives very low operating costs
Approximately 7 – 8 euros for 4-5 liters diesel to go 10km
Approximately 1 – 2 euros for 10-20 kWh electricity to go 10km
A fast charged hybrid can run completely electrically all day yet always have the reliability of the diesel backup generator when required
No fossil fuel burning, Umea's electricity is 100% free of CO2.
No pollution
No noise; the e-Traction wheel motors are probably the quietest bus motors in the world.
Small infrastructure investment – the Opbrid Bůsbaar charging station can be shared by multiple buses for low overall cost.
No overhead wires
Backup generator for diesel reliability in all conditions

About Opbrid S.L.

Opbrid Bosbaar is a brand of Opbrid S.L., based in Granada, Spain that is focused on providing products and services to enable the emerging fast charged bus industry in Europe and worldwide. We believe that the fast-charge concept will revolutionize the urban bus, changing it from a loud, polluting, CO2 emitting vehicle into clean, quiet, sustainable electric transportation. For more information on the Bůsbaar and fast charged buses in general, visit or contact Roger Bedell at +34 626 855 662.


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Roger Bedell
Opbrid S.L.
+34 626 855 662
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