Of all passengers using public transportation in the world, 80% go by bus. Buses are easy to use in almost all types of traffic and are in many parts of the world the only public transportation. In London, buses are one out of many means of transportation, and play an important role when the city aims to reduce traffic.
North London’s Green Lanes is a chaotic experience during rush hour. At the bus stop outside the popular pub The Fox, commuters get on and off a never-ending stream of red doubledeckers. Noise pollution from cars and diesel buses fills the street with an aggressive roar.
All this makes the contrast from Volvo’s new hybrid double-deckers all the more evident. When it arrives at the bus stop, the diesel engine shuts down completely. You are left with a comforting silence that remains even as the hybrid bus leaves the stop, only using its electric motor to accelerate.
“It’s fantastic how quiet it is when the diesel engine is turned off and it only runs on electricity,” says Daniel Clarke, one of the commuters standing in line at the bus stop. “I can’t even imagine what the difference would be if all buses were hybrids.”
Arriva’s Wood Green bus garage in Northern London is a pioneer of hybrid buses in London. In the summer of 2009, six brand new Volvo B5L Hybrid Double Decker buses arrived at the garage that has had previous experience of hybrid technology.
“We received the first hybrid buses in 2007 and now have a total of 11 hybrid double-deckers at Wood Green,” says Ian Tarran, engineering director at Arriva London. “Our experience of hybrid technology has been positive so far and all our staff, from mechanics to drivers, are pleased to be involved.”
Ian Tarran sees a bright future for hybrid buses. “The potential for fuel savings is massive,“ he says.
The Mayor of London and Transport for London, the body responsible for London’s transport system, has made the hybrid buses a key part of their strategy for public transport with less environmental impact. To really put the Volvo Hybrid Double Decker to the test, bus route 141, was selected. The route starts at Palmers Green and ends at London Bridge, with a total length of 9 kilometres and a tour frequency of 6-12 minutes.
“The average speed is about 8 kilometres per hour and a bus stops on average every 150 metres, at traffic lights, bus stops and so on. It is a rather intense and challenging route in heavy traffic and with many passengers, so the buses have to work quite hard – up to 17-19 hours per day,” says Ian Tarran.
“The field tests have shown that the fuel consumption of the Volvo Hybrid Double Decker is within our goals,” says Niklas Deras at Volvo Buses.
“On route 141, the buses have the toughest cycle possible and still their fuel consumption has been reduced by over 30 per cent compared to the regular diesel buses on route 141.
FACTS: Uo to 35% lower fuel consumption
The Volvo B5L Hybrid Double Decker is equipped with a diesel engine with smaller cylinder volume than normally, since it’s combined with an electric motor. It is the electric motor that is running the bus accelerates to a speed of 15-20 km/h. When the bus is underway, the parallel hybrid system combines diesel and electric power to maintain speed.
At higher speeds, the bus uses diesel power alone. Regenerative braking energy charges the battery via the generator. Several of the Volvo hybrid auxiliary systems are powered by independent electric motors. These measures all contribute to high fuel savings on routes with frequent braking and acceleration, like city bus traffic. The parallel hybrid technology reduces fuel consumption and CO2 emissions by up to 35 percent compared to conventional diesel buses. In the hybrid configuration, the emissions of nitrogen oxide and particulates are reduced by up to 40-50 percent.
Download image of Volvo B5L hybrid bus
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