London hops on the eco-friendly band wagon by adding diesel-hybrid double-decker buses to its public transport fleet. We take a look

When it comes to implementing green technologies on public transport, Delhi is probably on the forefront, with all its buses and rickshaws now running on environmentally-friendly CNG. Of course London, undoubtedly one of the most congested cities in the world, isn't one to be left behind in this case. To further the green cause of the city, Arriva London received a delivery of six new Volvo B5L hybrid buses just last week. And of course, there's no better way to test the realities of hybrid technology than with public transport, where significant reductions in fuel consumption and emissions is not just desirable, but also a commercial necessity.

London's new hybrid buses are powered by Volvo's parallel hybrid I-SAM (Integrated Starter, Alternator Motor) technology, which integrates a powerful electric motor within a driveline complete with diesel engine and automatic gearbox, providing the best balance between cost and benefit. I-SAM also features electrification of engine driven auxiliaries such as the servo pump, air compressor, AC compressor, etc to further increase fuel efficiency. Service field trials have shown there will be significant reduction in CO2 emissions as well as nitrous oxides and particulates. This system has already been used on the Volvo 7700 Hybrid single deck buses in the company's home city of Gothenburg in Sweden, and has delivered fuel savings of about 30-percent, 5-percent more than what was anticipated.

With the addition of these new buses, London has become somewhat of a competitive testing market for hybrids as the Transport for London agency has already taken delivery of 17 buses equipped with BAE Systems' diesel-electric HybriDrive propulsion system late last year. This technology is quite similar to Volvo's I-SAM system as it uses a combination of diesel and electric motors that can power the bus independently or in conjunction. Going green is of course happy news for London's commuters as it ensures lower fuel consumption, less air pollution and best of all, as these buses feature stop-start systems, less noise as well.