Public focus on the effect of pollutants on health is putting a question mark over the future of diesel. So, what alternative could the industry adopt? A Low Emission Bus Workshop in Manchester last week helps operators with the answer
Few can doubt that the wind of change is gathering force when it comes to the power source for Britain’s coach and bus fleet.
As is now well documented, Euro 6 is becoming the standard for the London Ultra Low Emission Zone (ULEZ) and five other cities Clean Air Zones (CAZ). The driving force behind this tighter emissions standard is the growing concern over air quality and a big question mark over the credentials of diesel-engine vehicles is turning attention towards alternatives.
Such is the concern that many now believe that pure electric is almost certainly going to be the primary power for buses in the next 10 years, while gas is steadily gathering a band of loyal supporters.
Yet for most of the past decade diesel-electric hybrids have been a way of reducing fuel consumption and therefore reducing emissions, while for some the route to cleaner air has been to retrofit exhaust after treatment systems.
The result is a maze of options facing operators contemplating future fleet replacements and to help the Low Carbon Vehicle Partnership (LowCvp) held the first of a planned series of four regional workshops in Manchester last week.
Held within the imposing surroundings of the Great Hall in Manchester University’s Sackville Street Building and chaired by Mike Weston of the LowCvp Bus Working Group, the workshop was geared to informing and stimulating interest in low emission strategies.
The one-day workshop before a packed attentive audience provided some valuable insights into the operational experience of diesel-electric hybrids, biomethane gas, pure electric, exhaust after-treatment retrofit, and Euro 6 diesel
It builds on LowCvp’s Low Emission Bus Guide, which assesses eight low carbon options and aims to point operators and local authorities in the direction of the best technology and fuel best suited to different routes and conditions. The Guide includes case studies and provides a bus operator perspective, according to LowCVP Project Officer Daniel Haynes.
Meanwhile LowCvp’s Head of Projects Gloria Esposito provided an overview of the national policy position, explaining the growing focus on Clean Air Zones, while suggesting that this provided a “huge opportunity for the bus industry as the urban mobility solution.”
There was further endorsement of the bus industry’s potential for growth as the result of clean air policies when Nicola Kane of Transport for Greater Manchester (TfGM) outlined the authority’s long term strategy. She said: “The vision is world-class connections supporting sustainable economic growth along with ambitious carbon reduction targets. The challenge is moving to a low carbon fleet. If we can address buses this will bring a big impact on air quality.”
Meanwhile York was the first city in the UK to have a Clean Air Zone. Derek McCreadie, Programme Manager, City of York recalled the steps taken over the past five years. Explaining the decision to introduce electric buses on the city’s park and ride services, Mr McCreadie said: “Buses are a big part of the contribution (to NOx pollution). Although 0.3% of the vehicles create 20-30% of NOx, we found that the most frequent buses contribute 80%.”
Operational perspective
Tom Large, Head of Engineering, Arriva Yorkshire told the workshop that his experience of Arriva’s 12 Volvo B5LH parallel hybrids was “largely positive.” Fuel consumption was 8.75pmg, which is 20% up on comparable diesel buses, while maintenance costs on the five-year Volvo contract are “considerably higher” and will be probably be brought in house. His concern is the effect of battery packs on whole life costs.
Dave Smith, Fleet Engineer, Arriva North West presented a very positive picture of the ongoing results of operating 10 MAN gas-powered buses in Runcorn. He says that an order for a further nine buses was proof of their success in terms in terms of operational costs (21% saving) and reduced CO2 savings.
Steve Cornes, Projects Manager, Nottingham City Council provided the workshop with a detailed report on the learning curve experienced during the introduction of 58 pure electric buses. Detailed planning and patience had been required but zero emissions and the use of off peak charging combined with 30% energy regeneration made it all worthwhile.
The overall impression was that choice of technology was a case of horses for courses. James Blackshaw, Technical Projects Manager, First Group related the improved efficiencies incorporated in the latest generation of diesel buses as a result of the Group’s Millbrook test regime. “Efficient Euro 6 must be the most effective solution,” he said.
Cleaner diesel emissions from older Euro 3 and Euro 4 school buses has been pursued to good effect by TfGM. David Ives, Fleet Manager spoke of significant improvements brought about by retrofit of SCR after treatment systems.
Though Mr Ives wasn’t alone in noting that driver performance had a significant effect on the results, while grant availability remains a significant factor for those pursuing alternative power sources.
- Details at www lowcvp.org.uk
