The process of climate change mitigation and the transition toward low-carbon energy systems associated with it are probably the greatest collective action problems humankind has ever confronted. According to the conventional theory of collective action, rational agents pursuing their own interest will not participate in collective efforts because they have incentives to free-ride on the constructive behavior of others. More recently, various authors have argued that complex collective action problems faced by large groups, such as climate change mitigation, are often decomposable into social dilemmas at a smaller scale, some of which are more easily surmountable given pre-existing social norms and trust networks. Accordingly, community-based energy (CBE) projects have been perceived as ideal institutional models to foster pro-environmental attitudes and behaviors. However, the analytical scrutiny of CBE projects is scarce. The main purpose of this dissertation is thus to assess the potential roles CBE projects may play in a low-carbon transition, focusing on the case of renewable energy (RE) cooperatives. First, the thesis examines how cooperative membership relates to three outcomes of interest: financial investments in cooperatives, attitudes toward RE and wind energy technologies, and electricity consumption behaviors, based on quantitative empirical evidence from Flanders. Regarding financial investments in the organizations, the results show that several categories of members with different motives and levels of engagement can be distinguished. This heterogeneity is explained by contrasts in terms of institutional settings, spatial patterns and attitudes to the diffusion of institutional innovations. In addition, social identification to the cooperative and a dense social network structure have a significant positive effect on financial contributions. Regarding attitudes toward renewable energy technologies and onshore wind energy in particular, our results suggest that the main difference between members and non-members is that the latter are not more opposed to wind energy than the former, but are actually more indifferent. Significant differences among cooperative members are also highlighted, illustrating their heterogeneity. As for energy consumption practices, it is shown that electricity consumption is positively related with cooperative membership, suggesting that high use consumers have greater incentives to join a community-based organization which provides assistance and advice on the adoption of green technologies and energy efficiency measures. Second, the thesis seeks to analyze how the direct institutional and physical contexts influence cooperative members’ decisions and behaviors. The distinction between ‘mutual’ and ‘public’ benefit organizations and the spatial patterns of the projects developed by cooperatives are emphasized. The findings reveal that an orientation toward mutual benefit is associated with lower social identification to the cooperative and weaker ties between members as compared to an orientation toward public benefit. Spatial patterns also play a significant role. Indeed, members who are more spatially concentrated have more social interactions with fellow members, identify more strongly to their cooperative and are more pro-environmentally oriented. Third, the research connects these empirical findings at the local level with perspectives at higher levels in order to shed some light on the conditions of emergence of RE cooperatives. A qualitative comparison between Belgium, the UK, Germany and Denmark emphasizes the contextual factors that facilitate or hinder the creation and development of RE cooperatives at the national level. The comparison highlights a double-edged phenomenon: prevailing and growing hostility towards cooperatives, on the one hand, and, on the other, strategic reactions to this evolution. What comes out indeed is that, throughout most of these countries, the emergence of some coordinated inter-organizational actions among cooperatives enables them to survive in their critical environment.