Here, Steve Rawson, Head of Retrofit Engineering at Eminox, looks at the reasons why air pollution is driving new emissions regulations that will affect buses and coaches

“2020 has emerged as the final deadline for addressing the worst air pollution problems in UK cities. However, with public attitudes becoming less tolerant and research by health organisations highlighting the health dangers, it is becoming increasingly likely that new emissions regulations may be introduced earlier.

New London Mayor, Sadiq Khan, is to consult on bringing forward the capital’s Ultra Low Emission Zone (ULEZ) from 2020 as well as expanding the area out towards the North and South circular. In a clear sign of his intentions, he said: “I have been elected with a clear mandate to clean up London’s air – our biggest environmental challenge.” An early introduction of ULEZ will affect buses and coaches, with the minimum requirement being Euro VI or retrofit equivalent (with approval requirements still to be defined).

In addition, the government has announced that five other cities; Birmingham, Leeds, Nottingham, Derby and Southampton, will introduce Clean Air Zones (CAZ) by 2020. Although exact air pollution regulations to enter these zones are still to be defined, current plans state that vehicles must meet at least Euro VI emissions levels for NOx. These Zones won’t affect private car owners, but will affect buses, coaches, taxis and HGVs (the Birmingham and Leeds zones may also affect light goods vehicles). Consultation on the detail of CAZ is expected to start in late summer 2016.

Finally the forthcoming ‘Buses Bill’, will mean that combined authorities with elected mayors could take responsibility for the running of local bus services, giving franchising powers to local authorities.

Retrofitting for air pollution regulations

Retrofitting will be a cost effective alternative to new vehicles, plans for London ULEZ and the five other CAZ, all incorporate options for a retrofit alternative.

We are already working on the latest updates to our SCRT retrofit technology and have been able to demonstrate emission levels equivalent to Euro VI.

Our SCRT retrofit system has been independently tested over the MLTB cycle (which simulates challenging urban operating conditions in London) and shown to cut NO₂ by 96.7%, along with NOx (95%), PM (98.8%), HC (98.1%) and CO (96.5%). In effect, it practically eradicates NOx emissions entirely, ensuring that the vehicles meet even the most stringent new legislation. This is backed by data from real world operation.

Air Quality experts at King’s College London have attributed a 16% reduction in NO₂ pollution on Putney High Street to SCRT technology retrofitted to 93 buses.  Eminox upgraded the buses and Kings College identified a clear decrease in NOx and NO₂ concentrations following the retrofits

NO₂ concentrations on Putney High Street were previously amongst the highest in London and far exceeded limit values. As well as the large drop in kerbside NOx, when the systems were fitted, there was a sustained decrease in NO₂ concentrations of 12% at the kerbside over the full period of the study.  Therefore, the SCRT retrofitting programme has been particularly effective in reducing the number of short term exceedances of NO₂ limits.

Using PEMS (Portable Emissions Measurement System), averaged across a bus route in Brighton, the total NOx emissions from a Euro III bus retrofitted with an Eminox SCRT was substantially below those of all other buses tested, including a Euro V hybrid vehicle. On-road tests also show that SCRT retrofit solutions really work in tough urban operating conditions where pollution is worst.

So retrofit SCRT is expected to be a preferred way forward for many bus and coach operators looking to meet the new standards –that is because it can upgrade vehicles at a fraction of the cost of buying new and is capable of achieving near-zero emissions levels, on a par with Euro VI.

A need for change
Underlying all of this is the scale of change required to cut UK emissions in the worst areas, which cannot be underestimated – 38 out of 43 air quality zones in the UK fail to meet legal limits on NO₂.  The WHO (World Health Organisation has also identified nine urban areas in the UK that are breaching safe health levels for Particulate Matter.

Air pollution contributes to about 40,000 early deaths a year in the UK, according to a recent report published by the Royal College of Physicians and the Royal College of Paediatrics and Child Health. The cost of treating these illnesses and premature deaths adds up to more than £20 billion every year, a figure that simply can’t be ignored by government, with the result that air pollution will remain an area of legislative focus.

SCRT is a practical and cost effective way of tackling this problem because it has shown in real-world tests to help older diesel vehicles achieve near-zero pollution levels, specifically targeting NO2 and particulate matter. Knowing that this retrofit option is available means that coach and bus operators can future-proof themselves against new legislation.”