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Clean Transport

Published on September 25th, 2014 | by Steve Hanley


Volvo Plug-in Hybrid Bus Ready To Roll

September 25th, 2014 by  

Volvo 7900 PHEV Bus

Originally posted on GAS2

The Volvo 7900 PHEV may be the world’s most perfect bus. Designed to operate in nearly silent electric mode 70% of the time, it uses 60% less energy and produces 75% fewer carbon dioxide emissions than a conventional diesel powered bus. And it’s 600 volt lithium ion battery pack can be recharged in under 6 minutes via a roof mounted pantograph.  In theory, it could make indoor bus stops possible, which would encourage more commuters to ride the bus and leave their cars at home.

The 7900 PHEV is a close cousin to the current Volvo 7900 Hybrid but features a more powerful motor that grunts out 850 lb-ft of torque and larger 19 kWh battery. The motor is coupled to a 240 hp 4 cylinder diesel engine that adds another 600 lb-ft of torque. To make full electric operation possible, a DC/DC inverter steps down the 600 volts stored in the on board battery pack to 24 volts for the electric steering, electric air compressor for the brakes and electric air conditioning system.

Volvo will officially introduce its 7900 PHEV at the International Auto Show for Commercial Vehicles in Hannover, Germany on September 25.  It has already signed contracts with several European cities for the first deliveries. Hamburg, Luxembourg and Stockholm will implement the new bus system in 2014 and 2015. Series production is scheduled to start in early 2016.

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writes about the interface between technology and sustainability from his home in Rhode Island. You can follow him on Google + and on Twitter.

  • Brooks Bridges

    I view it as a practical transition period solution. For shorter routes, 100% on electric sounds possible, but diesel allows flexibility for longer routes. Or for the time period before charging stations are built. I am NOT a fossil fuel proponent but do know modern diesel are getting pretty squeaky clean re emissions, including soot.

  • Bob_Wallace

    Then there’s the South Korean bus that charges wirelessly as it drives.


  • JamesWimberley

    The telling date is that production won’t start until 2016. By then BYD will no doubt be rolling out the successor to the K9 bus, which is already better than Volvo’s prototype. Zero emissions is better than a 75% reduction.

    • Offgridman

      I have to agree with you, the all electric buses from Proterra, BYD, or the other company doing conversions on older models to all electric are the perfect buses. These from Volvo with their reductions in diesel usage are nice and definitely an improvement over the buses that only run off from fuel. But the perfect ones are those that eliminate diesel use

  • Will E

    imagine a line off these poles on the side of the highway.
    a power line in between, and a connection as shown on the picture.
    then you have the electric highway for bus and trucks.
    battery power for short distance.
    fossil free and as far as you want to go all electric.
    fueled by Solar and Wind Power. along the highway.

  • Brokelyn

    It’s too bad they chose diesel over CNG which would lower emissions even further. Perhaps that will be offered to cities that already use CNG buses.
    Bus drivers have regular rest breaks along their route and that’s where the power connection would allow the perfect battery top-off. This is cool stuff.
    Now the government needs to mandate bus fleet efficiency like this if they want any transit dollars. It really can be this easy.

  • Matt

    70% on electric, wouldn’t that depend on the route and number of stops with chargers. Is the diesel only for long time between chargers, or is it also needed for hills and high speed? For flat cities (NY, London, Paris, …) where the bus is on fixed routes (non-highway express routes); shouldn’t pulling the diesel out be a cheaper option? Or were they thinking that transit buys are conservation by nature and they still need to see hybrid in the name in order to buy a bus, can’t yet go full EV.

    • Will E

      go full EV , forget diesel.
      time Tesla comes with a bus

      • No way

        It’s already here. It’s called the BYD K9

        • Bob_Wallace


          They must have used the same naming service that Chevy used when they tagged one of their cars to Nova.

          • No way

            Well.. if you might be competing with the Greyhound buses then why not? 🙂
            But it could be worse… Like when Honda tried to sell a car translated to “Honda Pussy” in Europe.
            For some reason they desided to rename it Honda Jazz (but just shortened it from Fitta to Fit in the US).

            To make it even funnier they had some slogans on the pamplets that they gave out to the reporters and such before launching the cars such as “small on the outside, roomy on the inside” and “for your daily pleasure”. 😉

          • Bob_Wallace

            I purchased a different brand…

          • No way

            Haha… brilliant 😛

          • paqza

            Do explain. Are you talking about the myth about “Nova” cars in Spanish?

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