The North Sea plays a pivotal role in Europe’s energy transition, offering vast potential for offshore wind energy expansion. One promising approach to harness this potential is the hub and spoke concept, in which offshore wind farms connect to energy hubs that distribute electricity to surrounding countries and other hubs. Despite the strategic importance of this approach, there remain significant uncertainties regarding the system's design, including decisions about installed capacity, hydrogen integration methods, and future electricity demand.
This study addresses these uncertainties by first identifying the offshore wind generation goals of the countries surrounding the North Sea. Next, it evaluates various methods for integrating hydrogen production into the energy system. Based on the findings, multiple scenarios were designed to represent a spectrum of future system arrangements.
A scenario-based energy flow model was created to simulate and compare the behavior of different network designs under varying assumptions about electricity demand and hydrogen inclusion. The analysis reveals that electricity demand has a major impact on system design. Higher demand reduces the availability of surplus electricity, thereby limiting both hydrogen production and the cable capacity needed to transport electricity across the network. The results also show that onshore hydrogen production requires approximately 11% more cable capacity than offshore hydrogen production, although it avoids additional offshore infrastructure costs.

This study concludes that the North Sea hub and spoke energy system could serve as a foundational element of a flexible, robust, and integrated European energy system. However, to support effective planning and implementation, several critical areas require further research. These include the development of a time-based optimization model that incorporates real weather data and demand profiles to reveal seasonal and daily performance patterns. Moreover, there is an urgent need for more accurate projections of future electricity and hydrogen demand, as these will heavily influence infrastructure decisions. Lastly, detailed economic assessments must be conducted to better understand the investment requirements, market dynamics, and potential policy interventions needed to make this vision feasible.
By clarifying key design choices and highlighting critical next steps, this research contributes to a more informed and coordinated development of the North Sea energy system, advancing Europe’s transition toward a sustainable, carbon-neutral future.