New York City Orders 850 Diesel Hybrid Buses

While green car enthusiasts wait for the next generation of hybrids that use different fuel sources or rely more on electricity, big cities are now placing orders for buses that combine hybrid controls, diesel engines, and electric drives. Yesterday, Daimler AG received an order for 850 of its Orion VII hybrid diesel-electric buses from MTA, the agency that oversees public transit in New York. The new order will double the MTA’s diesel hybrid bus fleet to 1,700, making it the largest in the world.

The Orion VII buses are powered by BAE Systems’ HybriDrive technology, which are about 30 percent more efficient than conventional diesel models. Unlike today’s consumer hybrid vehicles, the buses are propelled solely by an electric motor that is powered by a diesel-driven generator. The diesel engine’s only function is to power a generator that produces electricity for the motor.

Daimler claims the buses burn cleaner than conventional diesels, producing about 90 percent less soot. That’s because the diesel engine runs at a nearly constant speed to power the generator, rather than the varying speeds of a conventional bus as it starts and stops. Additionally, the buses offer regenerative braking, which means the drive motor is used to slow the bus. This effectively turns the motor into a generator that produces more power to be stored in batteries, and later used to move the wheels.

The new order provides 745 new buses for New York City Transit, and 105 for its sister agency, MTA Bus. It will be fulfilled by 2010. In a related story, the city of Ottawa’s public transit agency ordered 202 of the same hybrid-electric diesel buses.


  • sean

    Can someone exlain to me why we produce electricity by a diesel engine and then use the electricity to drive the car. I think the big power plants produce electricity at a much higher efficiency. A plug-in, without the diesel engine is more desirable. Or I miss something here?

  • David Long

    Sean, because to move a bus during the day you’d need a battery the size of Brooklyn to store enough power. You need to carry your BTUs a lot more efficiently. This is why freight trains are diesel-electric – the diesel engine does nothing but power the electric motors.

  • Simon

    Speaking of diesel electric trains, why is it that they don’t ever have a pantograph? (the arm that goes up and down to get power from an overhead line)

    I mean, couldnt they get their power from the suburban train network whilst in the city, then switch over to getting it from the deisel when in the country?

    There must be a technical reason.

    Actually – why not have buses with pantographs and some roads with electrical cables?

  • indigo

    Am I missing something, or do these hybrid busses work just like how GM wants the Chevy Volt to function? If so, why isn’t the Volt out on the roads now?

  • mark

    why not just buy fuel cell buses? then you have no emissions, can re-fuel quickly, and hydrogen can be produced using (at least partially) renewable energy?

  • MICHAEL PELEKIS

    COST OF FUELL CELL $4,000/kW

    http://www.energy.ca.gov/distgen/equipment/fuel_cells/cost.html

    A 150 KW ENGINE FOR A BUS WOULD COST 600,000$

    HYDROGEN FUEL CELLS EMIT WATER VAPOUR
    WATER VAPOUR AT HIGH CONCENTRATIONS IS NOT A HARMLESS GAS

  • Oklahoma Honda Civic Hybrid Dr

    thats awesome, I wish Tulsa would get its act together and purchase some of these buses.

  • Collin

    You guys (and gals) are awesome!

    Simon… The pantograph idea is GREAT!!! Use the electricity when it’s available. Buses could do the same thing but in either case, the cost to install the pantograph system is very high and the systems are quite ‘unsightly’ and (on rare occasion) dangerous.

    Sean… It’s just a matter of battery technology getting better and better. If these buses are designed properly, installing a better battery (down the road) should allow the system to turn the diesel off once the battery is fully charged and back on when needed (say at half or one-third charge).

    Mark… Fuel Cells are great but still very expensive (price is a very real obstacle) and there is no infrastructure (hydrogen fueling stations) in Manhattan.

  • greengal

    Does anyone have any information with regard to the availability of these diesel/hybrid technologies being used in Motor Homes? If so, what kind of costs are we talking about and what mileage improvement expected? While some may argue that those that can afford RV’s can afford the fuel – now pushing $4. per gallon, but I hardly think that is the point. Everyone should want to reduce emissions and use fuel more efficiently.

  • tapra1

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