Diesel Electric Bus

Volvo's diesel electric city bus.

Volvo India showcased the 7700 Diesel-Electric Hybrid city bus at the 2012 Delhi auto expo. The Volvo 7700, like all other Volvo city buses, will come with a low floor design for easy ingress and egress. Volvo 7700 hybrid bus will feature a 5 liter MD5 four cylinder, turbocharged and intercooled diesel engine which produces 210 Bhp of peak power and 800 Nm of peak torque. This engine is mated to an electric motor which will be powered by a lithium-ion battery. Volvo claims a whopping 35% reduction in fuel economy and a considerable 40% - 50% cut in exhaust emissions. 

The 7700 can be operated in 3 modes, all electric, diesel and diesel-electric. The electric motor will power the bus for speeds of up to 20 Kph, after which the diesel engine will take over. The Volvo 7700 is a parallel hybrid. It will keep on charging the electric battery through the diesel engines alternator, thus not constantly replenishing the battery. The Volvo 7700 also comes with Start-Stop system and  Regenerative Braking technologies. The engine shuts off at traffic signals or whenever the bus is stationary for more than a few seconds and the electric motor will kick in. This will help in conserving the battery stack and increasing the fuel efficiency. Volvo will offer a 105 seater version of the 7700 hybrid bus in India. It will also soon be running on the streets of Gothenburg.