Abstract

Biogas is largely utilised as vehicle fuel in public bus transport in Sweden today. This study investigates opportunities and barriers for continued domestic use and production of biogas, in relation to the ongoing electrification of public bus transport. The analysis is based on interviews with actors in public transport and the biogas sector, experts on biogas systems, and representatives for alternative user segments. Three regions were chosen as case-studies for investigations of prospects in public transport, i.e. Stockholm, Västra Götaland and Skåne, though alternative uses were studied from a national perspective. In addition to public transport, considered uses include road transport, sea transport, industries, and electricity and heat production. The study identifies a broad agreement among stakeholders that renewable resources should be implemented where they provide most benefits from a system perspective. Therefore, electric public buses are valued in urban environments, while biogas solutions are found suitable for regional routes. Biogas is further viewed as environmentally beneficial in all user segments except continuous electricity and heat production, where it largely would replace renewable rather than fossil sources. Regarding costs and competitiveness, probable future uses are identified within light and heavy-duty road transport, and in consumer-oriented industries, i.e. the food industry. Economic support in policy instruments is further considered essential for continuous development of the Swedish biogas sector, though current influential instruments, e.g. the tax exemption, are described as short-term and unpredictable. The willingness to pay for the collected societal benefits of biogas further decrease in transitions from public to private consumers, and as biogas solutions simultaneously are linked with limited or uncertain competitiveness in these sectors, risks prevail that such transitions could imply stagnations and declines in biogas use and production, given today’s situation. Idag används biogas till stor del som drivmedel för bussar inom kollektivtrafik i Sverige. Denna studie undersöker möjligheter och hinder för en fortsatt nationell användning och produktion av biogas, i samband med att bussar inom kollektivtrafiken nu elektrifieras. Analysen är baserad på intervjuer med aktörer inom kollektivtrafiken och biogassektorn, sakkunniga inom biogas, och alternativa användare av biogas. Tre regioner, Stockholm, Västra Götaland och Skåne, valdes som fallstudier för analys av möjligheter för fortsatt användning inom kollektivtrafiken. Alternativa användningar studerades istället ur ett nationellt perspektiv, och inkluderade vägtransporter, sjöfart, industri och el- och värmeproduktion. Studien visar att det råder enighet mellan intervjupersoner att förnybara resurser över lag ska användas där de medför störst samhällsnytta sett till samhället i stort. Inom kollektivtrafiken beskrivs elbussar därför som fördelaktiga i stadsmiljöer, medan biogas ses som lämpligt i regional trafik. Biogas framställs dessutom som miljömässigt fördelaktigt i alla alternativa användningsområden utom kontinuerlig el- och värmeproduktion, eftersom då främst förnybara och inte fossila resurser ersätts. Med hänsyn till kostnader och konkurrenskraft ses lätta och tunga transporter tillsammans med kundnära industrier, t.ex. livsmedelsindustrin, som troliga framtida användningsområden för biogas. Ekonomiskt stöd från styrmedel bedöms vara nödvändigt för en fortsatt utveckling av biogassektorn i Sverige, även om dagens styrmedel, t.ex. skattebefrielsen, beskrivs som kortsiktiga och oförutsägbara. Betalningsviljan för biogasens samlade samhällsnyttor minskar också vid en övergång från offentliga till privata kunder. Eftersom biogas därtill har en begränsad eller osäker konkurrenskraft jämtemot andra alternativ i de privata segmenten, identifierar denna studie risker för stagnation eller nedgång i användning och produktion av biogas vid en eventuell utfasning från den offentliga sektorn, givet dagens situation.

Abstract

across the world, in Turkey, several studies have been carried out by local government to use sustainable and 100% zero-emission public transport following increased public awareness. Increasing greenhouse gas emissions (GHG) due to transportation systems in the world make it necessary to establish &ldquo zero-emission sustainable transportation systems&rdquo in Turkey. In this study, an economic analysis based on actual field data is presented for Istanbul Electricity, Tramway and Tunnel General Management (IETT) to seek the suitability of an electric bus concept for Istanbul conditions. For this purpose, a dynamic model based on the Total Cost of Ownership (TCO) from well to wheel has been proposed for the three groups of transportation, namely diesel, CNG (compressed natural gas) and electric buses. The data source used in the proposed approach is created by performing actual field performance tests for diesel, CNG and electric buses under real Istanbul road, time, and trip conditions. Afterwards, the Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PB) methods considering TCO values and updated unit prices are carried out for the investment versus profitability analyses to compare the different public bus concepts. The results show that the electric bus concept with a charging station depot achieving sustainable and zero-emission goals will be the driving force to advance the electric bus concept for Istanbul Public Transport. Document type: Article

Abstract

Nowadays, the conversion of diesel fueled public bus fleets into those powered by electricity is one of the most important tasks for public transport operators. In the frame of European Commission funded projects (“Eliptic” [Commission, 2015], “ZeEUS” [Commission, 2014]), there are at the moment several demonstrations in different European (big) cities. Besides purely demonstrating the general technical functionality, finding Business Cases is also a crucial task, since the operation with the new technology should be at least not significantly more expensive than compared to Diesel, besides having clear societal and environmental benefits."br" Within this context, the presented work focuses on the detailed comparison of two novel technological concepts of electric buses which are currently demonstrated in several European cities in the frame of the “Eliptic”-project:"br" 1) Opportunity-charging of battery electric buses taking energy from local DC tram grid"br" 2) Trolley-Hybrid buses (Buses being fed by overhead catenary and being able to cover parts of their routes by on-board batteries)"br" The investigations are based on already existing and potential future electric bus network and real operation in different cities and are performed in direct cooperation with the respective public transport operators to obtain meaningful results. A technical, economic and ecological presentation and comparison of the different approaches is the main target of the work."br" For this purpose, detailed analyses are performed in order to calculate the Total-Cost of Ownership (TCO). This comprises all relevant technical investment- and running costs over a certain period under consideration. Sine it is representing an important cost-factor of the new system, the battery is particularly considered regarding the expected lifetime in different operation scenarios.