The Baltic countries are exploring diverse ways to achieve renewable energy objectives, with a particular emphasis on utilizing photovoltaic (PV) technologies in urban areas. Despite the northerly geographical location, PV energy has proven effective, particularly in individual households under the net metering scheme. Energy communities (EC) in urban areas have the potential to support sustainable energy transition by promoting local generation and increasing resilience. However, the broader adoption of rooftop PV systems faces numerous challenges, including technical limitations and legislative gaps. This study examines challenges encountered by community energy projects in residential apartments through a case study in the Latvian context. The paper provides a comparative analysis of PV community implementation scenarios across the three types of typical apartment buildings. The study demonstrates a number of fundamental obstacles that hamper the development of ECs in apartment buildings. The results indicate that the economic benefits of ECs largely depend on electricity market price, and that selection of optimal community design is the key aspect for minimizing investment risks amid market and legislative uncertainty. Results indicate that individual households may have limited motivation to form ECs under current policies. Finally, the insights provided help shape suggestions for future research.

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.