This article examines the interaction between centralized and decentralized energy systems, and more specifically the evolving role and regulatory model of transmission electricity grids in facilitating the deployment of distributed energy resources (DERs). The central electricity grid is essential for ensuring security of supply, but it faces new challenges when more decentralized, intermittent renewable energy and flexible demand are added to the energy system. The total blackout that occurred on 28 April 2025 in the Iberian Peninsula illustrates these challenges. In this new transmission-DER nexus, a fundamental question is whether central electricity grids should be considered a common good, and if so, what this entails in terms of regulatory model and legal requirements. After a brief introduction, the article reviews the definition of common goods and explores the extent to which it applies to the transmission electricity grid and the consequences thereof. Gaps in existing regulatory model under European Union (EU) law are identified, discussing the role of transmission system operators with respect to decentralized actors and vice versa, focusing on five specific areas of interaction: grid planning, grid investment regulation, grid capacity management and system costs, balancing duties, and resource adequacy. As operations become more complex, the use of digital tools for DER management systems is raised. The conclusion presents the possible legal approaches to address the identified shortcomings in the central grid regulatory model.
European Energy and Environmental Law Review