The Route to Cleaner Buses A guide to operating cleaner, low carbon buses Preface Over recent years, concerns have grown over the contribution TransportEnergy is funded by the Department for Transport of emissions from road vehicles to local air quality problems and the Scottish executive to reduce the impact of road and to increasing greenhouse gas emissions that contribute to transport through the following sustainable transport climate change. One result of this is a wider interest in cleaner programmes: PowerShift, CleanUp, BestPractice and the vehicle fuels and technologies.The Cleaner Bus Working New Vehicle Technology Fund.These programmes provide Group was formed by the Clear Zones initiative and the advice, information and grant funding to help organisations Energy Saving Trust TransportEnergy programme. Its overall in both the public and private sector switch to cleaner, aim is to help stimulate the market for clean bus technologies more efficient fleets. and products. Comprising representatives of the private and CATCH is a collaborative demonstration project co- public sectors, it has brought together users and suppliers in financed by the European Commission's an effort to gain a better understanding of the needs and LIFE-ENVIRONMENT Programme. CATCH is co-ordinated requirements of each party and to identify, and help overcome, by Merseytravel, with Liverpool City Council,Transport & the legal and procurement barriers. Travel Research Ltd,ARRIVA North West & Wales Ltd, This guide is one output from the Cleaner Bus Working Compagnia Trasporti Pubblici (Naples) and Suceava Group. It investigates the potential benefits and the issues Municipality (Romania) as partners. associated with the use of ‘cleaner’ vehicle fuels for bus Acknowledgements operation in urban areas.The prime aim of the guide is to help local authorities to gain a better understanding of the technical This guidance document has benefited from financial or and economic issues involved in cleaner fuel buses, and to take in-kind contributions from the Clear Zones programme, forward appropriate actions to promote their use. the Energy Saving Trust, the European Commission CATCH project and Volvo Bus Ltd. A Clear Zone is a defined urban area, which exploits new technologies and operational approaches to improve quality We would also like to thank Mercedes-Benz for providing of life and support economic growth, whilst minimising the the photo of the fuel cell bus shown on the front cover. adverse impacts of its transport systems.The Clear Zones initiative seeks to develop this concept and promote the development of relevant technology through partnerships between cities, industry, academia and government. Clear Zones is co-ordinated by Transport & Travel Research Ltd, and supported by the Department for Transport. Contents Executive Summary 2 1 Introduction 4 2 Emissions Reduction Technologies 7 3 Cleaner Fuels 9 4 Environmental Performance 15 5 Current Experience with Cleaner Fuel Buses 18 6 Future Developments in Vehicles and Cleaner Fuels 43 7 Action Plan 46 8 Conclusions 49 Appendix 1 Information Sources 50 Appendix 2 The UK Bus Industry 51 Appendix 3 Legislation 52 Appendix 4 Cleaner Bus Working Group Members 53 1 Executive Summary UK road transport contributes to national emissions of Operating experience from several case studies in the UK and gaseous pollutants, which can lead to both global climate elsewhere have demonstrated some of the environmental change and a variety of local air quality problems.The UK bus benefits of reduced emissions of local air pollutants and fleet is predominantly powered with diesel using compression greenhouse gases from the use of alternative cleaner fuelled ignition engines.Alternative ‘clean’ transport fuels, which offer vehicles. However the total lifecycle costs of these vehicles, the prospect of reducing some of these emissions and taking into account the operating costs, capital expenditure improving energy efficiency, are currently available, and include: and maintenance costs, are greater than those for the equivalent buses operating on ultra-low sulphur diesel fuel. Liquefied petroleum gases and compressed natural gas Hence the economic case for cleaner fuels is not commercially used in internal combustion engines; attractive to bus operators.Although several of these alternative fuels have lower rates of fuel duty than are applied Hybrid electric vehicles which combine electric motor to ULSD, the current Fuel Duty Rebate system (Bus Service drives with internal combustion engines fuelled by diesel Operators Grant) for bus operators reduces the incentive to or petrol; switch to alternative fuels. Before large-scale market uptake ‘Biodiesel’ fuel used in internal combustion engines in becomes likely, the cost of alternative fuel powered bus blends with diesel fuel. operation needs to become comparable with diesel. Government grants are available towards the additional cost of There are also longer-term prospects of using other ‘low purchase or conversion to a cleaner fuelled vehicle, funded by carbon’ fuels such as bioethanol, biomethanol and hydrogen TransportEnergy through the PowerShift programme.The fuel cell technology. New Vehicle Technology Fund and CleanUp Demonstration programme also part-fund demonstration and research The costs and benefits of using clean fuels in public transport projects into clean bus systems, and programmes funded by vehicles need to be compared with the use of ultra-low sulphur the European Union may also be relevant. diesel fuel in vehicles complying with current EU emissions standards (Euro III).All forms of alternative road fuels have Hydrogen fuel cells are often promoted as the fuel of the advantages and disadvantages – for example: capital and future given that it offers the possibility of zero emissions. operating costs, emissions, refuelling infrastructure and refuelling Most major manufacturers have extensive R&D projects time, vehicle range, and loss of payload space. Hence changing underway, with evaluation trials on buses, cars and vans already from diesel fuel requires careful consideration.Apart from cost in progress. However, commercially viable versions of this factors, the levels of emissions make some fuels more suitable technology are approximately 15-20 years off.Apart from for certain types of uses than others.The potential introduction getting the technology to work reliably in everyday working of Low Emission Zones in some city centres, and the provision environments, there is also the question of how the necessary of congestion charges which could offer exemptions for low re-fuelling infrastructure is to be put in place, and the emission vehicles are major commercial factors that must be investment costs that would be required. considered for urban bus operation. Clean fuel buses may be a The eventual market for alternative fuels and technologies in solution.The tax, duty and grant regime in place can have a bus operation will be strongly influenced by: major impact on fuel choice. The key factors involved in each of the clean fuel alternatives The predicted costs and benefits to the customer and that are currently available are listed in the following Table. operator being commercially acceptable; Fuel tax and subsidy arrangements applicable to the UK bus industry; Whether there are access restrictions to some urban centres for all but low-emission vehicles; How much increasingly stringent European emissions control legislation may favour alternative fuels; The extent of other benefits from alternative clean fuels such as performance improvements, quiet operation and improved fuel economy. 2 Fuel Type Pros Cons Water Emulsion Lower emissions of NOx and particulate matter, Only one supplier in the UK. Diesel possible CO2 benefits from improved fuel consumption. No modifications needed to engine. Liquefied Low CO2 emissions, similar to diesel; generally low Currently limited but expanding refuelling Petroleum Gas levels of other pollutants; low levels of engine noise; infrastructure (1200 sites in UK); lower fuel economy; (LPG) low fuel duty compared with diesel. often loss of some load space; issues regarding toxicity and the combination of high density and flammability of the gas. Compressed Low CO2 emissions, similar to diesel; generally low Currently limited refuelling infrastructure therefore Natural Gas levels of other pollutants; low levels of engine noise; requires dedicated refuelling equipment; lower fuel (CNG) low fuel duty compared with diesel.Vehicles widely economy; loss of some load space (more so than available in Europe. LPG); vehicles are currently significantly more expensive to purchase and maintain than diesel buses; experience of unreliability in early trials Battery Electric Zero emissions at point of use; extremely cheap fuel; Requires recharging systems; batteries and vehicles Vehicles silent operation can be expensive; pollution created at power station not exhaust pipe; limited range between charges; battery durability Hybrids Low CO2 and other pollutants; very fuel efficient; New technology, so at present vehicles are expensive; (Electric/Diesel) driving experience very similar to diesel vehicle; only also currently limited vehicle choice.The widespread fuel required is diesel therefore plentiful - no need to introduction of hybrids would require new skills for recharge batteries separately although some require maintenance staff and electrical technicians. charge stabilisation, once or twice per week Biodiesel Lower