Expanding London's hybrid fleet

MQT on 2013-02-25
Session date: 
February 25, 2013
Question By: 
Stephen Knight
Liberal Democrats
Asked Of: 
The Mayor


Given that levels of particulate emissions are broadly similar between conventional diesel buses and diesel-electric hybrids (see MQ 3404/2012), why are you not concentrating more on fitting diesel particulate filters to all London's buses before expanding the hybrid fleet?


Answer for Expanding London's hybrid fleet

Answer for Expanding London's hybrid fleet

Answered By: 
The Mayor

Officers are drafting a response which will be sent shortly.

Written response received on 13/03/13.

It does not make sense to do this when new hybrid and conventional diesel buses will be fitted with a diesel particulate filter as a standard component of their exhaust systems from January 2014.

Particulate matter from the bus fleet has fallen sharply from 200 tonnes in 1997 to around 17 tonnes in 2011/12. The introduction of ultra low-emission Euro 6 engine buses from 2014 will continue this downward step change in exhaust matter.

Current diesel-electric hybrid buses also reduce CO2 and NOx emissions by roughly 30 per cent and 20 per cent respectively, and are significantly quieter than conventional diesel buses. The New Bus for London reduces CO2 and NOx emissions by around 50 per cent. In addition to reducing air pollution, they help to reduce the carbon footprint of the bus fleet and contribute to achieving stated targets in my Climate Change Action Plan.