Volvo’s new Electric Hybrid (PHEV) buses with overhead fast charging enter scheduled service in Hamburg for first time; Innovation Route 109

19 December 2014

New Volvo Bus 7900 Electric Hybrid (plug-in hybrid) buses (earlier post) began scheduled operation in Hamburg on 18 December, coinciding with the opening of the Innovation Route 109. The public transport company in Hamburg, the Hamburger Hochbahn AG, is using the route to run comparative tests of innovative drive technologies under the strict everyday conditions of scheduled services. The city of Hamburg intends to acquire only emission-free buses from 2020 on.

Alongside three Volvo 7900 Electric Hybrid buses, Volvo’s diesel hybrid buses in both 18 m articulated and 12 m versions will also be tested on the route, as well as battery fuel cell buses and fuel cell buses from other manufacturers.

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Volvo 7900 Electric Bus in service in Hamburg, parked at a terminal with charging pantograph. Click to enlarge.

The Innovation Route 109 of HOCHBAHN will be almost exclusively served by buses with innovative drive technologies. Different types and drive modes for the sustainable buses of the future are to be tested in parallel and under identical conditions. Conventional diesel buses will also be used on the route to serve as reference vehicles in the comparison of the innovative drive concepts. With the newest vehicles, the HOCHBAHN is expanding its rolling development lab for modern drive technology to a total of about 65 vehicles.

The Innovation Route 109 runs from the new Electric Bus Terminal near Hamburg Central Station to the final stop at the underground station in Alsterdorf. With a length of about 10 kilometers (6.2 miles), it’s highly suitable for the Volvo Electric hybrid buses, with their plug-in technology that permits full electric operation over at least 7 kilometers. Charging takes place at the two bus terminals.

The plug-in hybrids are based on the Volvo 7900 Hybrid, Volvo Buses’ second series-produced hybrid bus model. The plug-in hybrids have been further developed, and enable rapid recharging from electricity grids via a pantograph on the roof.

The 4-cylinder, 5-liter Volvo D5F diesel engine produces 215 bhp and is installed vertically. The 150 kW electric drive motor delivers 1200 N·m (885 lb-ft) of torque. The conventional hybrid offers up to 37% fuel savings compared to a diesel version and 40-50% lower exhaust emissions. The plug-in versions have a larger battery pack, making it possible to drive up to 7 km using electricity only—about 70% of the route distance.

Volvo estimates the fuel savings to be about 75% on a city bus route of 10 kilometers, compared to a Euro 6 diesel bus.

When the bus reaches its parking position at the terminal under the charging mast, the pantograph is lowered to both of the charging bars on the roof of the bus when the driver presses a button. The complete charging process takes only six minutes.