Review, Definition and Challenges of Electrical Energy Hubs
Giacomo Bastianel, Jan Kircheis, Merijn Van Deyck, Dongyeong Lee, Geraint Chaffey, Marta Vanin, Hakan Ergun, Jef Beerten, Dirk Van Hertem
TL;DR
This paper addresses the need for a robust, operation-focused definition of offshore, high-capacity grid projects that aggregate GW-scale generation and interconnect multiple control areas. It proposes a formal definition of Electrical Energy Hubs (EEHs) as multifunctional nodes that aggregate local generation and provide multiple interconnections, managed separately from existing control areas. It analyzes technical challenges across control, planning, and protection, and maps these to EEH functionalities, including issues of grid congestion, loss-of-infeed limits, high DC fault currents, fault detection, and interoperability. By classifying current and planned offshore grid projects against the EEH definition, the work identifies which projects qualify as EEHs and highlights implications for grid codes, permitting, and funding, offering a structured framework to accelerate large-scale offshore HVDC development.
Abstract
To transition towards a carbon-neutral power system, considerable amounts of renewable energy generation capacity are being installed in the North Sea area. Consequently, projects aggregating many gigawatts of power generation capacity and transmitting renewable energy to the main load centers are being developed. Given the electrical challenges arising from having bulk power capacity in a compact geographical area with several connections to the main grid, and a lack of a robust definition identifying the type of system under study, this paper proposes a general technical definition of such projects introducing the term Electrical Energy Hub (EEH). The concept, purpose, and functionalities of EEHs are introduced in the text, emphasizing the importance of a clear technical definition for future planning procedures, grid codes, regulations, and support schemes for EEHs and multiterminal HVDC (MTDC) grids in general. Furthermore, the unique electrical challenges associated with integrating EEHs into the power system are discussed. Three research areas of concern are identified, namely control, planning, and protection. Through this analysis, insights are provided into the effective implementation of multi-GW scale EEH projects and their integration into the power grid through multiple interconnections. Finally, a list of ongoing and planned grid development projects is evaluated to assess whether they fall within the EEH category