Decision-making and decision support connected to biogas use in Sweden

Sammanfattning: Human activities cause many sustainability challenges in the world, which need to be dealt with. One way to decrease the negative impacts related to those challenges is by replacing currently dominating technologies with better, alternative technologies. However, such shifts are not easy to achieve – for example, each new user has to make a decision to start using the technology.The aim of this thesis is to contribute to a greater understanding of what the decisions to use alternative technologies are based on and how the decisions can be supported. In order to achieve this aim, the thesis focuses on the decisions of private companies’ and public organizations in Sweden of whether or not to use biogas in Sweden. The thesis is based upon six appended papers, which are used for addressing three research questions: How do biogas compare to other potential alternatives? Why do decision-makers in Sweden find it interesting to use biogas, and what makes them hesitant? And, how can decision support be used in decision-making to deal with complexities connected to biogas decisions?It is concluded that biogas has environmental and social advantages compared to several other renewable alternatives, but that it can be more expensive. The technical maturity of biogas use depends partly upon the usage area – biomethane buses is a mature area while heavy trucks is less mature. Biogas is perceived by decision-makers as a good environmental option and a better long-term solution than several other renewable alternatives since there are investments done and since the policymakers seem positive towards biogas. Public organizations tend to look at the broader positive aspects of biogas, such as energy security and nutrient recovery, while private companies tend to be more focused on biogas as an environmental action that can benefit the image of the company. However, decision-makers can be hesitant towards biogas due to economic or policy aspects or a lack of technical maturity. The decision-makers can also experience a lack of knowledge that makes them uncertain about biogas. Decision support can help the decision-makers in different ways, with different tools being more suitable for different parts of the complexities connected to biogas decisions. Multi-criteria assessments can help the decision-maker focus on several impacts at once and making the decision process transparent for trade-offs, while socio-technical scenarios can help the decision-maker understand how the wanted changes can be realized.