When the operator Göteborgs Spårvägar started its field test using Volvo’s new Volvo 7700 Hybrid bus a year ago, it was the first company in the world to deploy the bus in operation. Prior to the field test, it was hoped that fuel consumption could be reduced by 25-30%. Traffic in the first year has shown that the bus surpassed this figure with a saving of 30-35%.
“The bus uses only 2.67 liter per 10 km, corresponding to three normal passenger cars,” says Edward Jobson, Environmental Manager at Volvo Buses. “That means that the bus releases only 20 g of carbon dioxide per passenger kilometer, which is a fifth of what a hybrid car, for example, emits.”
Lars-Börje Björfjäll is the President of Göteborgs Spårvägar and he is very pleased with the field test.
“We are gratified and proud that we could be involved and contribute to the development of a more environmentally friendly alternative for public transport. Our company will be a precursor and work continuously to reduce the environmental impact of our operations.
“This past year we have been able to show that it is possible to reduce carbon emissions by 30%, halve emissions of nitrogen oxide and particles and lower total energy consumption. This is an important step in the right direction.”
The bus has mainly been operational during the year in the Hisingen area of Göteborg and Lars-Börje Björfjäll believes that the bus is a resounding success.
Volvo’s hybrid bus has a small diesel engine and an electric engine that can be operated individually or jointly. Energy from braking is used in the batteries to operate the electric engine. The diesel engine shuts off at bus stops and the bus starts by using its electric engine. The diesel engine starts up again once the bus has reached a speed of 15-20 kph.
“At first, many passengers thought that there was something wrong with the bus when the engine kept shutting off,” explains Edward Jobson. “But most people have got used to it now and everyone who I have spoken to appreciates the silent running of the engine and the bus stops that are no longer covered in exhaust fumes.”
Volvo Buses will commence serial production of the hybrid buses at the end of May and currently has 50-60 hybrid buses on order in Europe, although no more have been ordered for Göteborg.
“I would very much like to see us use more hybrid buses in Göteborg. However, the environmental strategy the city of Göteborg is to adopt for the area of public transport is a matter decided by the public transportation authorities in Göteborg,” says Lars-Börje Björfjäll.
The field test in Göteborg will continue for some time. A particle filter, which will further reduce particle emissions, is next in line to be tested.