To further improve the environment in the Swedish capital, Scania is now starting full-scale operational trials with six ethanol-fuelled hybrid buses. The hybrid technology will reduce fuel consumption by 25 percent. The use of ethanol will reduce net carbon dioxide emissions by up to 90 percent. The trials will be run in cooperation with Stockholm Public Transport (SL), and the operator Swebus.
During the two-year trial period, the buses will serve one of the more demanding and heavily used lines in Stockholm.
“These operational trials will give us valuable experience of how hybrid technology shapes up in real life, as well as of its environmental effects,” says Göran Hammarberg, Head of Bus Development at Scania.
The trials are also supported by the Swedish Energy Agency and the Swedish Environmental Protection Agency.
In the new Scania OmniLink low-entry buses, Scania combines better fuel economy with the use of renewable fuel. The hybrid technology is expected to save at least 25 percent on fuel, and the fact that the diesel engines run on ethanol will reduce carbon dioxide emissions by up to 90 percent compared to a conventional diesel bus.
“Long-term, hybrid technology will help us reach even more ambitious environmental objectives for urban traffic,” says Göran Hammarberg.
Scania has chosen a series hybrid solution for these buses, a technology with the greatest benefits in stop-and-go city driving. What characterises a series hybrid powertrain is that there is no mechanical connection between the combustion engine and the propulsion motor.
Electrical power is generated by a diesel engine adapted to run on ethanol. Mechanical energy is converted to electrical energy in a generator.
The six buses are driven by an electrical motor that doubles as a generator when braking. Energy is stored in supercapacitors with considerably longer service life than today’s batteries.
Since the start in 1989, Scania has supplied some 400 ethanol city buses to SL and this has strongly contributed to an improved environment in central Stockholm.
Scania regards ethanol as the most attractive renewable fuel available for city traffic today, taking into account factors like availability, infrastructure and proven technology.