Diesel emissions in focus as new proposals target air pollution in major cities
Further pressure seems to be mounting on diesel emissions following new Government proposals to tackle high levels of nitrogen dioxide (NO2) in major city centres across the UK.
Announced by the Department for the Environment, Food and Rural Affairs (Defra), the proposals are intended to reduce levels of nitrogen dioxide – a key constituent of diesel emissions – in a number of regional zones by 2020 and in London by 2025.
The proposals are targeted especially at major cities such as London, Birmingham, Leeds, Nottingham, Southampton and Derby.
Defra has produced an overview document for the UK as a whole and a zone plan for each of 38 zones, from a total of 43, that were initially identified as exceeding the maximum annual limit for nitrogen dioxide in 2013.
Local authorities asked to take action
The plans ask local authorities to look at further action such as creating Clean Air Zones, introducing low emission buses and taxis, and using data to create new road layouts.
Defra added that options local authorities could consider include:
• Networks of electric car charging points
• Introducing low emission buses and taxis or converting fleets
• Upgrading cycling infrastructure
• Introducing or expanding park and ride schemes
London has already signalled its intentions to clean up emission levels in the capital, and in 2020 will introduce the UK’s first ultra-low emission zone. Carbon limits to qualify for the 100% discount from the London congestion charge are likely to fall to 75g/km at this time.
The first fully electric bus route in the UK will launch later this month in Croydon and, by 2020, there will be 300 electric buses running in central London and 3,000 double-decker hybrid buses.
The move towards embracing clean air technology includes the Government’s ambition that almost every car and van on our roads will be zero emission by 2050.
This will be incentivised by at least £200 million of government grants for plug-in cars and vans and £50 million of support for local authorities and transport operators to convert their taxis and clean up bus fleets.
Response to the initiative
Motoring organisation, the RAC, said that banning cars from towns and city centres was potentially damaging for businesses and for individuals, especially without any clear guidance on long-term solutions.
The RAC said there was no consistent approach to a solution which needed to target three key elements.
Firstly, there was the need to identify the vehicles that generated the most pollution which varied by vehicle type, age and usage.
Secondly, there needed to be a focus on the areas with the worst air quality problems. Cars were not necessarily the problem as buses and taxis also made significant contributions to poor air quality.
And thirdly, there needed to be recognition of the fact that fleet operators and general motorists had been encouraged by the Government’s own taxation system to purchase small fuel-efficient diesel vehicles with a low carbon footprint.
Latest emissions regulation comes into force
The latest Euro6 emissions regulations for diesel cars and vans came into force from the beginning September 2015, and are specifically targeted at unwanted tailpipe emissions, especially nitrogen oxides.
The new rules cut the permissible limits for NOx dramatically, from the current 180mg/km to just 80mg/km, with the aim of limiting the impact on the environment and public health.
Manufacturers have been forced to introduce new, more expensive clean-up systems, including after-treatment systems, such as Selective Catalytic Reduction, which works with a reduction agent, typically known as AdBlue.
Another method is the Lean NOx trap, which is fitted instead of the normal oxidation catalytic converter.
These new systems come at an increased cost, some of which may be borne by the vehicle manufacturers, but much of which could be passed on.
This increased complexity of technology also seems to fly in the face of a number of diesel’s main attributes, those of simplicity, reliability and longevity.
However, there seems to be growing acceptance of the fact that the latest generation lean-burn petrol models face no such problems. Their upkeep and maintenance, compared to future diesel models, is less complicated with lower front end costs, improved economy and lower carbon emissions.
What’s the best fleet mix going forward?
Diesel is still the dominant force in fleet motoring and looks set to remain so for some time to come.
CLM’s advice to its clients on the best mix of vehicles for their fleets is to look closely at the type of driving that they most commonly do.
For fleets with a large percentage of high mileage journeys, typically on motorways, diesel still remains the most cost advantageous option due to lower fuel consumption, despite prices harmonising at the pumps recently.
For fleets with mainly low mileage needs and short journeys, petrol engined-models can present the best option because of their lower capital outlay compared to diesel equivalents, which have a high front-end price premium.
And for fleets that operate in a largely urban environment with a lot of stop-start driving, the best mobility options can be low emission cars – hybrids, range extenders and pure EVs. The final choice comes down to the flexibility requirements of the fleet and overnight parking and recharging arrangements.