Third of London buses to run on biodiesel

Almost 3,000 London buses will be running on a ‘greener’ blend of diesel fuel by March 2016, according to TfL, in bid to cut carbon emissions

Almost a third of London buses will be running on a ‘greener’ blend of diesel fuel by March 2016, according to Transport for London (TfL), in a bid to cut transport carbon dioxide emissions.

Just under 3,000 London buses will run on biodiesel blend from March 2016

TfL announced this week (December 21) that just under 3,000 of the capital’s 8,900 buses will by March next year be powered by the B20 fuel blend, which is a mix of 80% standard diesel with 20% biodiesel.

This ‘cleaner burning fuel’ is made from blending diesel with renewable biodiesel made from waste products such as cooking oil and tallow from the meat processing sector.

It is estimated that buses running on this waste-based B20 fuel produce fewer ‘well to wheel’ emissions than a bus using ordinary diesel, with TfL estimating a CO2 reduction of 21,000 tonnes each year from the 3,000 buses running on biodiesel from March.

Two of the capital’s bus operators, Stagecoach and Metroline, have signed deals with biodiesel supplier Argent Energy for the supply of the B20 diesel, which has already been trialled for two months on 642 buses operating out of four Stagecoach depots in London.

TfL requires that the fuel is made from waste, rather than crop-based products, and it is blended at Argent Energy’s blending facility in London.

Mike Weston, TfL’s director of buses, said: “Our bus fleet is now making a major contribution to improving air quality and bringing down CO2 emissions. This improvement, which will reduce CO2 emissions by 21,000 tonnes each year, is being introduced now with no extra spend needed and no long delay for the fitting of new kit. It’s just one of a number of measures we are taking to make London’s environment better for everyone.”

Dickon Posnett, development director of Argent Energy, added: “The ever-growing demand to reduce greenhouse gases from transport is well recognised. TfL and the Greater London Authority have actually done the research and have now shown they have the understanding of the immediate benefits that high bio-blend diesel can bring.”

Air quality impact

However, while biodiesel has been found to produce fewer CO2 emissions, information on its impact on air pollution is not as conclusive.

Defra’s Air Quality Expert Group (AQEG) published a paper in 2011 — ‘Road Transport Biofuels: Impact on UK Air Quality’ — which concluded that “Results from research studies on the effects of biofuels on vehicle emission are inconclusive and show a high degree of variability”.

It also called for “further research on the effects of different strengths of biodiesel fuels on mass emissions of NOx, primary NO2 and PM and the characterisation of particulate matter and chemical composition of organic compounds emitted from modern diesel engines and vehicle technologies so that the full air quality impacts of biodiesel consumption can be assessed.”

London

London’s bus network is one of the largest in the world, according to TfL, carrying almost 2.4 billion passengers a year and using around 240 million litres of fuel. Under the new deals, about 80 million litres of the new greener blend of fuel per year will be consumed.

The capital’s bus fleet has more than 1,500 hybrid electric buses — increasing to 1,700 by 2016 — and 15 pure electric buses. Over 2,000 older buses have also been retrofitted with selective catalytic reduction (SCR), reducing their NOx emissions by up to 88% per bus, according to TfL.

In addition, eight zero emission hydrogen buses operate on route RV1, between Covent Garden and Tower Gateway. TfL said it will also soon be trialling inductive charging technology that will enable special extended range diesel electric hybrid buses to wirelessly charge their batteries while they wait at bus stands.