November 14, 2013
Volvo Bus’ plug-in hybrid. The pantograph for rapid charging can be seen on the roof. Click to enlarge.
Field tests being conducted in Gothenburg show that Volvo Buses’ plug-in hybrid reduces fuel consumption by 81% and total energy consumption (diesel plus electricity) by 61% compared to a comparable Euro 5 diesel bus. (Earlier post.)
The field test in Gothenburg began in June 2013 and includes three plug-in hybrid buses, the batteries of which are rapidly recharged at the terminals. This makes it possible for the buses to run on electric power for most of the route.
The plug-in hybrids are based on the Volvo 7900 Hybrid, Volvo Buses’ second series-produced hybrid bus model. The plug-in hybrids have been further developed, and enable rapid recharging from electricity grids via the Opbrid Bůsbaar pantograph on the roof.
The 4-cylinder, 5-liter Volvo D5F diesel engine produces 215 bhp and is installed vertically. The conventional hybrid offers up to 37% fuel savings compared to a diesel version and 40-50% lower exhaust emissions. The plug-in versions have a larger battery pack, making it possible to drive up to 7 km using electricity only—about 70% of the route distance. The batteries are charged at the bus terminus via the Bůsbaar for between six and ten minutes.
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 [21 mpgUS]. That’s 81% less fuel than the equivalent diesel bus consumes.In addition to the significant energy savings and reduced impact on the environment, this technology gives passengers a more comfortable and pleasant journey and improves the working environment of the drivers.
—Johan Hellsing, Project Manager for the field test at Volvo Buses
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 from GS Buss really appreciate the quiet, vibration-free ride that you get with an electric powered bus.The field test of the plug-in hybrid buses in Gothenburg involves 10,000 operating hours 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.
A number of European cities are showing an interest in the plug-in hybrids. Hamburg and Luxembourg have already signed contracts for supplies of the buses in 2014 and 2015. Volvo Buses is working together with the city councils, public transport authorities and providers to develop long-term sustainable solutions for public transport. Volvo Buses plans to commence commercial manufacture of plug-in hybrids towards the end of 2015.
Those engaged in the plug-in hybrid project in Gothenburg are Volvo Buses, Göteborg Energi, Business Region Göteborg, Trafikkontoret and Västtrafik. The project is co-financed by Life+, the EU’s financing program for environmental projects.