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

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.

Volvo 7900 Electric Hybrid Hamburg 2014 084
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.

Video of the Volvo PHEV in Hamburg, including footage of the pantograph in operation.



No doubt a solid design execution for which Volvo has become well-known.

Somewhat OT, somewhat connected comes this article from China business news service The Standard on the topic of pure battery busses:

The experiment of using pure electric buses has failed in all the tested cities," Caixin quoted Wang Zidong, an official in charge of China's power vehicle test center, as saying.

"We are `burning a lot of money' and no good commercial model has been formed."A dual- power trolley bus might replace electric buses.

Wang said two reasons led to the difficulty of putting pure electric buses into commercial operation. First is the lofty infrastructure investment.

"For example, during the APEC meeting, Beijing used 200 pure electric buses. Just building charging stations cost at least 60 million yuan (HK$75.6 million). How can a city bear such an expense?" Wang said.

Second, the maintenance fee is costly. "Batteries of such vehicles have short life, so they should be changed quite often. But it costs hundreds of thousand yuan to change a battery. Always the buses were set aside after the battery is used," Wang said.


The experiments continue. Electrification progress will surely continue, but perhaps not with the same players nor the same design concepts as we've imagined.


Unbiased testing and critical (German style) evaluation will establish the comparative viability of each technology.

Eight (8) fully electric Gulliver Technobus have been in regular operation, between lower and upper town, in Quebec City since 2008. I used that (excellent very low cost) service many times during summer holidays. Drivers claim that those e-buses run all day on one full ($3.25) slow charge. All 8 units are still in fulltime operation.


I think Mr. Wang should look at the cost of burning diesel. Not just the pump price, but the cost of air pollution to the health of his citizens.
However, I'd like to know more about these failures. A BYD bus shouldn't need its batteries changed until about 8 years unless something is very wrong. (3000 cycles LFP, one cycle per day).

Indeed, Volvo's execution of the plug in hybrid is excellent. Based on their well tested hybrid, it will be a solid workhorse, and very flexible since it can revert to normal hybrid when charging isn't available.

Certainly 100% grid electricity is the goal, but 80% grid power isn't bad, since previously it was 0% for their normal hybrid!

Go Volvo!


A very small (10 to 20 KW) emergency power unit (EPU)should be enough with about 200 to 300 Kwh of long lasting batteries.

It doesn't have to be diesel EPU. A lighter multi fuel unit would do.


BYD stock is down significantly after this news. A lot has to do with it's approach. With a 324 kWh Lithium Iron Phosphate battery of their design and a 155 mile range. Volvo has a better approach with the PHEV hybrid and 19 kWh battery, achieving 75% fuel reduction. The diesel range extender is particularly important in cold climates like Sweden where battery range can be impacted.
Other electric bus manufacturers are looking at reduced ranges with fast charging. The Proterra Bus uses a 54-72 kWh Toshiba SCiB Lithium Titanate battery which allows over 10,000 charges in as short as 5 minutes. (check out "Proterra Selects Toshiba SCiB Cells for Next-Gen Electric Bus",Green Car Congress, 10 September 2014).


I wonder why not using supercaps for bus plugins. The pack would be 10 times larger but for the bus that's not an issue. 1 t of supercapacitors would satisfy all needs. That would be O maintanace solution.


There are 4,5 and 6 cylinder turbo diesel engines which can run as a gen set burning CNG with low particulates, they can even use some biodiesel for upper cylinder lubrication.

The diesel gen set extends range while the charging brings it up every hour as the driver takes a break. Anyone who thinks it is easy driving through traffic with drivers cutting in and 20 people on board should try it for a day.



FYI, the Quebec City "Écolobus" electric bus experiment has been cancelled due to high running costs (supposedly six times that of conventional buses). You have until the end of the month to take one last ride.


So – it sounds like more cases of the people being “ FORCED” into wasteful purchases by big business.

Only in these cases they are politicians and spend other peoples money, so I guess when told these systems are exciting but still a terrible waste of money, the politicians would reply; "and your point IS?

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