Individual households, responsible for 25% of total energy consumption in Europe, are crucial actors in the energy transition. Although various policies and energy choices are available for such actors (e.g., individual solar photovoltaic or community energy systems), they are usually restricted to municipal governance, and public opinion towards national energy policy is not strongly presented. This study explores and describes the influence of the availability of alternative energy choices on different levels of governance to facilitate households' energy transition. An agent-based model is conceptualised through multi-level governance, the institutional analysis and development framework and the social value theory. To also address the ongoing energy crisis, the study focuses on the Dutch thermal energy transition and the thermal energy communities as a collective action for generating, distributing, and consuming renewable thermal energy and, therefore, three layers of energy choice alternatives are provided for households: national level (i.e., sources of natural gas), municipal/ community level (i.e., collective renewable energy technologies), and individual level. The results delineated the importance of the availability of alternative energy choices in the suggested multi-level governance collective action system. Such systems consumed only 12% natural gas, while they covered their thermal demand by increasing the capacity of collective thermal energy systems (83% on average) and adopting more individual thermal energy systems (heat pump, approximately 85%). Although the performances on voluntary blackouts/ discomfort (2.7% on average) and CO₂ emissions (85% reduction approximately) were also positive, this was reflected in a significant price increase.

In community energy systems, the energy demand of a group of households is met by collectively generated electricity and heat from renewable energy sources. What makes these systems unique is their collective and collaborative form of organization and their distributed energy generation. While these features are crucial to the resilience of these systems and are beneficial for the sustainable energy transition in general, they may at the same time undermine the security of energy within these systems. This paper takes a comprehensive view of the energy security of community energy systems by considering dimensions such as energy price, environment and availability, which are all impacted by decentralized and collective means of energy generation and distribution. The study analyses community energy systems' technical and institutional characteristics that influence their energy security. An agent-based modelling approach is used for the first time to study energy security, focusing on thermal energy communities given the considerable share of thermal energy applications such as heating, cooling, and hot tap water. The simulation results articulate that energy communities are capable of contributing to the energy security of individual households. Results demonstrated the substantial potential of energy communities in CO2 emissions reduction (60% on average) while being affordable in the long run. In addition, the results show the importance of project leadership (particularly regarding the municipality) concerning energy security performances. Finally, the results reveal that the amount of available subsidy and natural gas prices are relatively more effective for ensuring high energy security levels than CO2 taxes.