Field tests in Sweden have shown that Volvo’s plug-in hybrid buses reduce fuel consumption by 81% and total energy consumption (diesel plus electricity) by 61% compared to a comparable Euro 5 diesel bus. The silent, smooth ride is an added benefit.
“Our performance results are even slightly better than we had anticipated. The plug-in hybrid consumes less than 11 litres of fuel for every 100 kilometres,” said Project Manager Johan Hellsing. “Although there are many long, steep gradients on the routes, the plug-in hybrid buses can run on electric power for about 85% percent of the time. The diesel engine only kicks in when the bus needs some extra power. The test drivers really appreciate the quiet, vibration-free ride that you get with an electric powered bus.”
The field test of three buses began in Gothenburg in June, and will continue for most of next year. A demo project that will bring eight more plug-in hybrid buses into service will commence next year in Stockholm.
Volvo’s plug-in hybrid bus has an electric motor, a lithium-ion battery and a small diesel engine. It can be recharged in 5 to 6 minutes via a roof-mounted pantograph, and can run exclusively on electric power for approximately 7 km.
Several European cities have shown interest in the new buses. Hamburg and Luxembourg have already signed contracts. Volvo Buses plans to commence commercial manufacture towards the end of 2015.