How actors choose between alternative technologies in sustainability transitions: Insights from the decarbonisation of heavy-duty road transport

This thesis studies how manufacturers, policymakers and the general public choose between different alternative fuel vehicle technologies in the transition to net-zero, with a particular focus on the heavy-duty vehicle sector. The technological substitution of diesel trucks is a key element in achieving greenhouse gas emission reductions, but so far none of the multiple developed alternatives, ranging from bio- and synthetic gas trucks to fuel cell and battery-electric trucks, have reached a substantial number of registrations in the EU (ACEA, 2022d). Different choices be-tween these alternatives will have different consequences for the speed of the transition and the likelihood of achieving the EU’s net-zero targets. As policies target actors rather than technologies directly, knowledge about the motivations of the key actors involved in this selection process is necessary for policymakers to effectively incentivise those low- or zero-carbon alternatives that better meet societal goals while disincentivising others (Kemp, 1994).
The later phases of transitions, from take-off through acceleration, as well as actor behaviour at the micro level, have received limited attention in transition studies so far (Markard et al., 2020; Upham, Bögel, & Dütschke, 2020). As a consequence, less is known - in comparison to the build-up of multiple niches - about the process of "narrowing down" a variety of alternative technology options and about the motivations of actors in this process. The aim of this PhD thesis is therefore to gain a better understanding of the selection process between alternative fuel technologies for heavy-duty vehicle, with a particular focus on motivations and decision-making behaviour of the actors involved. From a review of the transitions literature on technology substitution, three groups of actors with a key role in technology selection were identified: manufacturers, policy-makers, and individual citizens as recipients and part of the public discourse represented in the media. For each actor group, a research question was developed and addressed in a separate re-search paper with a distinct set of theories and methods.
Paper I analyses the strategic technology choices of European heavy-duty vehicle manufacturers and identifies four alternative fuel vehicle (AFV) innovation strategy trajectories: proactive di-versifier, focused leapfrogger, initial incrementalist, and diverse follower. The results show that these trajectory differences can be partly explained by firm-level factors, such as the manufacturers’ presence in different markets, previously established competencies, and expectations. For policymakers, these results show that a lack of early and clear policy signals can lead to firms, especially comparatively smaller ones, to initially follow a more incremental path or to wait for others to take up the risk of moving towards more disruptive technologies. Such incrementalism may be a barrier to accelerating the transition in question.
Paper II focuses on policymakers' choices between two alternatives for charging battery-electric heavy-duty trucks in eight European countries and at the EU level. The paper finds that policy-makers’ support for dynamic charging was closely linked to the evaluation of the technology by industry actors involved in the consultation and policymaking process as well as their expectations of policy developments in other countries and at the supranational level. The case for dynamic charging was further complicated by changing interests, in particular in relation to the increasingly realistic option of covering long-haul transport with stationary charging, the lack of a clear new narrative, the cross-sectoral and line infrastructure characteristics of the technology, which would require greater cooperation between previously unrelated actors, and the timing of EU infrastructure policy initiatives before relevant field trials had been completed. Consequently, the results show that with the charging discourse in Germany and the EU dominated by vehicle manufacturers who have a greater interest in stationary charging, and without clear cross-country institutional cooperation and commitment, the future of dynamic charging remains unclear despite seemingly technology-neutral policies.
Paper III examines the effect that public discourse, as represented by the media, can have on technology choice. To this end, it examines the technology attitudes of individual German citizens towards AFV technologies and finds that positive media portrayal of battery-electric vehicles (BEV) can positively influence public attitudes towards this technology. For the more overarching approach in the final paper of the thesis, the empirical context was extended to include both heavy-duty and passenger transport. In addition to the effect on attitudes, the paper also shows that, while the majority of the coverage has focused on BEVs, the media portrayed the relationship between different AFV technologies and in particular between BEVs and fuel-cell electric vehicles (FCEVs) as uncertain, alternating between whether they were synergistic or competitive and whether one or the other would dominate in the future. Correspondingly, individual citizens had different expectations about which technology or technologies would prevail in the future. The results show that the public discourse, in which the researched strategies of manufacturers and policymakers are centrally manifested alongside the opinions of other societal actors, influences the evaluation of alternative technologies, which can, potentially feed back into decision-making through the different roles that these citizens take up in society. Policymakers need to be aware of these self-reinforcing cycles and, especially when designing technology-neutral policies, need v to take into account that both managers in manufacturing firms, the wider public, and policymakers themselves are recipients of a public discourse that can influence their attitudes beyond a purely technical comparison of the available technology alternatives.
Taken together, the studies reveal three main insights into how and why actors choose certain technology alternatives over others in the decarbonisation of heavy-duty road transport. To decide between alternatives, actors first assess the fit between alternative technologies and their own and collaborating actors’ competencies and interests. Technologies that better match these interests at a given point in time are more likely to be supported, even if their systemic contribution to the net-zero goal is not the highest. Second, actors do not focus only on the vehicle technologies themselves to make this assessment, but extend the comparison to other technologies, such as key component technologies or complementary infrastructure. For example, if the provision of infra-structure for one technology proves feasible for industry actors while another requires a government commitment that has not yet been made, as in the case of stationary versus dynamic charging infrastructure, manufacturers have an interest in building vehicles that match the infrastructure they can actively secure in order to meet relevant policy goals. Third, actors coordinate and collaborate directly with other actors to deal with uncertainties in decision-making – both through concrete joint technology development and by influencing and taking into account collective expectations.
The thesis thus contributes to the call for a more detailed study of actors in transitions and supports the previously observed importance of assuming heterogeneity of actors even within the same group, such as manufacturers or policymakers. Actors’ individual characteristics or previous experiences can result in different strategies and behaviours and thus support or hinder a transition. The thesis also adds to the literature on technology interactions in sustainability transitions from an actor perspective. The results show that even if the theoretical preconditions for choosing one technology are given in a selection environment, the preference for another alternative can effectively rule out this solution, especially when selection pressures become higher in the take-off phase of a transition. I suggest adding the conceptual layer of perceived and communicated inter-actions to account for the active ways in which actors influence technology choice, e.g. by framing two technologies as competing versus synergistic.
The results on technology choice also point to the importance of timing. If the innovation development stage of a technology is aligned with the current transition phase, the technology can more easily take advantage of windows of opportunity, such as policy changes, more readily while other technologies that can potentially contribute more (efficiently) to the net-zero goal but are not as well aligned, have a harder time being selected. The timing of actors' decisions in a transition may therefore put technologies at an advantage or disadvantage, depending on their individual level of development at a given point in time. Based on these results, I argue that future studies should conceptually and empirically distinguish more clearly between innovation and transition phases in order to better understand the factors working for or against certain technologies.
The thesis thus illustrates how an evolutionary perspective on sustainability transitions can benefit from an analysis of micro-level processes in which actors make their decisions based on both past experiences and expectations for the future, in constant interaction with the technologies they observe and other actors with whom they are connected. This complexity makes it clear that in order to understand and steer technology choices towards a net-zero future, an understanding that goes beyond the characteristics of the technology and towards the broader socio-technical system is crucial.