Energy communities (EnCs) are increasingly promoted as a means to support the decentralisation of energy systems and the integration of renewable energy sources, yet lack popularity and wide adoption. At the same time, demand flexibility is an important mechanism that can support EnCs by bringing additional benefits. Nonetheless, these concepts are often addressed separately or incoherently in policy and research, so the benefits of integrating them remain unclear. This paper aims to bridge these concepts and analyse their interaction. First, it sets the context by analysing legal and policy developments and the research landscape. It presents a systematic literature review of recent peer-reviewed publications, consolidating findings across three thematic areas: benefits and challenges for EnC members and system operators, approaches to enhance flexibility, and enabling factors, such as technical issues and data availability. The paper also outlines suggestions where further research is required to better understand and operationalise demand flexibility at the community level. The review shows that demand flexibility can significantly enhance the economic, environmental, and system-level benefits of EnCs but its integration remains fragmented and uneven. In particular, the complex interactions between internal and external incentives, stakeholder perspectives, technologies, and data availability are still insufficiently explored.

Active customers play a critical role in the successful implementation of support schemes, paving the way for the emergence of an energy community. This analysis explores the cooperation among active customers and the implications for developing energy communities. Furthermore, the motivations for consumers becoming active customers in the context of Latvia are illuminated, while also exploring the broader context of navigating the complex regulatory landscape to promote self-consumption. In contrast to prior studies, which often focus on individual or homogenous group participation, this analysis uniquely examines collaborative frameworks that incorporate varied customer categories and profiles. This approach not only underscores the role of tailored regulatory structures in fostering self-consumption, but also presents practical policy insights for incentivizing community-based energy models. The findings reveal that individual participation of active customers in support schemes only achieves the minimal self-consumption threshold in 47% of cases. In contrast, membership in an energy community significantly increases this rate, reaching 84%. These encouraging results underscore the importance of promoting energy community membership among active customers, which subsequently demonstrates substantial potential when promoted across diverse load profile categories. Additionally, the integration of photovoltaic and wind turbine technologies consistently improves self-consumption values.