Recently I visited Trondheim, Norway, because of their environmental ambitions. Some months ago ten Volvo 7700 hybrid buses were taken into service. The hybrid bus has the lowest environmental impact when compared to other bus alternatives such as alternative fuels.
The last couple of weeks the temperature has stayed below -10 C and often down to -20 C in the nights. I was told that ten buses have been in service all the time. The hybrid buses are kept outside all day and night and run with a fuel consumption below 30 litre per 100 km.
The hybrid buses pases the city centre of Trondheim frequently and now constitute a natural part of the clean and environmentally concerned city.