The Volvo 7700 is the first commercial viable hybrid buses on the market, and combines a traditional diesel engine with an electric motor and control unit, which results in 30 percent lower fuel consumption, according to a statement from the company.
The bus also has a lithium-ion battery which is charged when the brakes are applied, to later provide power to the electric motor.
The hybrid components are also manufactured by Volvo, which leads to better performance, according to the Håkan Karlsson, president of Volvo Bus Corporation.
“A common approach earlier was that bus manufacturers purchased hybrid components externally and attempted to adapt them to their own bus, but this is difficult,” he said in a statement.
“Since we developed the components internally, we have been able to optimize the bus’s fuel consumption fully. At the same time we could ensure very high reliability.”
The company also hopes to employ the hybrid technology, known as I-SAM, in its trucks and construction equipment.
The system shuts of the bus’s diesel engine during stops, and then relies on the electronic motor to start up again.
“When the bus reaches 15-20 kilometres per hour, the diesel engine starts up automatically,” said Karlsson.
The buses are set to be field tested in the public transit systems of London and Gothenburg during the autumn.
Volvo expects the first buses to reach customers in 2009, with mass production starting in early 2010.