100% biogas-fuelled public transport in Linköping, Sweden

My case study about Linköping’s 100% biogas public transport system was published in UN Habitat’s 2012 report “Urban Patterns for a Green Economy: Optimizing Infrastructure”.

Linköping promotes circular resource flows in the city by producing biogas from food waste, and using it to power the public transport system. Due to strong political support and local economic co-operation, the project has been a resounding success.

Project drivers and key aims

Sweden’s interest in renewable fuels began after the 1970s oil crisis which led to a massive hike in fuel prices. The country drew up plans for a natural gas pipeline that would run near Linköping, stimulating talk of the possibility of methane exports. But it was an internal rather than external push-factor that led to biogas development – poor urban air quality resulting from Linköping’s public buses (Berglund et al. 2011).

Emissions from the diesel buses were causing smog and soot to cover the city (Martin 2009). Leaders came together to discuss how to clean up the environment, while transforming the area and boosting the local economy (Martin 2009). The city opted for buses powered by natural gas, which could be supplied via the proposed pipeline (Ericson 2005). However, plans for the pipeline later fell through due to financial concerns (Martin 2009). Still enamored by the potential of gas, the city decided that the public transport system should run on locally-produced biogas (Berglund et al. 2011). The fuel is suitable for the city context as it can easily be collected from wastewater treatment plants and landfills. Also, it doesn’t require extensive fuelling infrastructure, which means it can be introduced in stages and doesn’t require as significant an investment (Ericson & Grahn 2010).

The main objective of the initiative was to reduce the pollution caused by public transport and provide a high quality environment for the citizens of Linköping (Barbero 2011). Key aims were to develop an integrated system of turning waste into biogas, which would connect rural and urban areas and fuel city buses (Barbero 2011). It was envisaged that over a number of years, the entire bus fleet would be replaced by bio-methane buses (Berglund et al. 2011).

Implementing the biogas transport system

In 1991 Tekniska Verken (TVAB), the municipal services provider, set up a pilot project of 5 buses powered by methane collected from the wastewater treatment plant (Barbero 2011).  Close collaboration between TVAB and Linköping University helped to speed up the development of biogas knowledge and production (Barbero 2011). Project evaluation revealed that the wastewater treatment plant would be unable to provide sufficient methane to power the entire bus fleet. It concluded that a separate production plant should be built, to control the input of feedstock and increase the output of biogas (Berglund et al 2011).

The source of feedstock was then expanded to include waste from the local slaughterhouse owned by Scan-Farmek. The Federation of Swedish Farmers (LRF) also came on board to supply feedstock in the form of crop residues and manure (Martin 2009). LRF agreed to purchase the digested residue (a by-product of the methane manufacturing process) as it is a valuable fertilizer (Ericson 2005). To solidify their co-operation, the three stakeholders started an associated company with shared ownership called Linköping Biogas AB (now Svensk Biogas) in 1995. The company received government funding to build a €140 000 methane production facility, completed in 1996 (Ericson 2005). The plant can treat 100,000 tonnes of waste per year, and produces 4.7 million m3 of upgraded biogas per annum (IEA 2005). The newness of the biogas concept made it too risky for the city to shoulder the financial and intellectual burden alone. Additional funding and expertise came from the municipality of Linköping, the county, the regional bus authority, LITA and TVAB (Berglund 2011).

The overhaul of the city’s public transport began in earnest in 1997, when 27 buses were replaced (Berglund et al 2011). In 2001, the sources of feedstock were again expanded to include waste from local restaurants. By 2002, all buses in the fleet were bio-methane driven, and in 2005 the world’s first biogas train became operational in Linköping (IEA 2005).

Impact on resource flows in Linköping

The transition from a fossil-fuel driven public transport system to one powered by biogas has improved more than just air quality in the city (Barbero 2011). Using biogas as a fuel results in very few hazardous emissions and greenhouse gases (Svensk Biogas 2011). The biogas from the plant replaces about 5.5 million litres of petrol and diesel each year, decreasing the need to import fossil fuels (IEA 2005). Carbon dioxide emissions have been reduced by more than 9,000 tonnes per year since 2002, lessening the city’s contribution to global warming (IEA 2005).

The production of biogas means that a waste product is turned into a resource – reducing the need for environmentally-destructive landfills and waste incinerators, and creating circular rather than linear resource flows (Ericson 2005). Specifically, the project has cut the volume of waste sent for incineration in Linköping by 3,422 tons annually (Svensk Biogas 2011). A by-product of the biogas process is biological fertiliser, which is purchased by the farmers’ association to replace energy-intensive, fossil-fuel based fertilisers.  As bio-fertilisers are made from a waste product, nutrients such as phosphorus are able to cycle through the economy, returning to nourish farmlands (Svensk Biogas 2011).

The project has also contributed to the city’s economic sustainability. Including local farmers in the production of biogas and sale of bio-fertilisers has increased their competitiveness and kept financial flows within the local economy (Ericson 2005).

Factors aiding and limiting success

It would not have been possible to implement such a novel project if there hadn’t been strong political support (Ericson 2005). Long-term co-operation between the city, farmers’ association, Linköping University, transit authorities, and other actors has arguably been the most significant factor contributing to success (Berglund et al. 2011). Stakeholders were involved early on in the project, and were allowed to make important decisions and raise difficult questions, encouraging their dedication (Barbero 2011). This involvement was so extensive as to be thought of as co-design. Most of the people involved were from the region, and were well-acquainted with Linköping’s ecological, social and economic situation.  Sufficient funds and a good measure of courage amongst decision-makers also helped the project come to fruition (Barbero 2011).

Despite strong political and social support, the project faced several challenges. Biogas production in Linköping was not considered profitable enough, and the company decided to expand regionally and also supply to the private transport market (Berglund et al. 2011).  The decision to expand was not unanimous, however, and Scan-Farmek and LRF sold their shares in the company to TVAB, which became the sole owner (Berglund et al. 2011). This move is likely to have increased rather than decreased economic inequality in the region. The expansion could have included small-scale biogas plants connected to a biogas grid rather than focus on large-scale production plants. This could have allowed greater coverage, reduced material handling costs and stimulated local economic development (Barbero 2011). Infrastructure issues, vehicle limitations, and legislation continue to limit biogas development in the region (Martin 2009).


The transition to a biogas public transport system has improved air quality for the citizens of Linköping. Co-operation between the city and local industries has helped to reduce waste and produce renewable fuel, while boosting the role of local agriculture. The potential for a biogas grid and the inclusion of smaller-scale production plants present significant opportunities for the expansion of sustainable transport.



Barbero, S. (2011) Systemic Design in Energy Sector: Theory and Case Studies. Acta Technica Corviniensis. Bulletin of Engineering. Tome IV. ISSN 2067-3809.

Berglund, B., Ersson, C., Ekland, M. & Martin, M. (2001) Challenges for developing a system for biogas as vehicle fuel – lessons from Linkoping, Sweden. World Renewable Energy Congress 2011 – Sweden Bioenergy Technology (BE) 8-11 May 2011, Linköping, Sweden.

Ericson, J. (2005) Svensk Biogas AB in Linköping (Sweden). Osmose. Available: http://www.osmose-os.org/documents/5/CaseStudyBiogasLinkoping(SE)2.pdf. Accessed online: 3 August 2011.

Ericson, J. & Grahn, M. (2010) Biogas as fuel for transport in Linköping (Sweden). Eltis. Available: http://www.eltis.org/index.php?id=13&study_id=2733. Accessed online 30 July 2011.

IEA. (2005) 100% Biogas for urban transport in Linkoping, Sweden. Available: http://www.iea-biogas.net/_download/linkoping_final.pdf. Accessed online 28 July 2011.

Martin, M. (2009) The “Biogasification” of Linköping: A Large Technical Systems Perspective. Environmental Technology and Management, Linköping Universitet. Available: http://www.iei.liu.se/envtech/forskning/forskningsprojekt/synergibiodrivmedel/1.187129/BiogasificationofLinkopingLTSFINAL.pdf Accessed online: 30 July 2011.

Svensk Biogas. (2011) Biogas – for a sustainable society. Available: http://www.svenskbiogas.se/sb/Biogas-Sustainable-society_eng_webb.pdf. Accessed online: 30 July 2011.



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