Wind-Resource Complementarity and Cross-Border Energy Security in the North Sea: A Data-Driven International Legal Framework for Offshore Wind Cooperation

The North Sea is becoming a shared renewable energy space in which offshore wind deployment, grid planning, market operation and environmental governance increasingly cross borders. This article asks how wind-resource complementarity can inform legal and institutional design for cross-border offshore wind cooperation. It combines a five-year representative-point wind-resource screening analysis using NASA POWER hourly data from 2021 to 2025 with functional legal–institutional analysis. The empirical analysis covers seven offshore or near-offshore representative screening points, hub-height correction to 100 m and 150 m, a wind-power proxy and wind-power-density proxy, low-wind frequency and low-wind event duration, monthly and interannual variability, pairwise correlation, CWCI and weighting sensitivity. The representative-point results suggest a mean 100 m corrected wind-speed range of 8.52 to 9.88 m/s, 4 m/s low-wind frequencies of 8.69% to 12.64%, and a maximum 4 m/s low-wind event of 173.0 h at NO_SOUTH. The baseline CWCI screening identifies DK West–BE Coast, DK West–FR Channel and UK East–FR Channel as leading within-sample pairs. The legal analysis uses these results as screening evidence for questions of data compatibility, hub-height assumptions, low-wind consultation, hybrid offshore grid governance, market coordination, cumulative environmental assessment, investment regulatory space and crisis dispute prevention. The article proposes an operational five-pillar framework with institutions, instruments, implementation steps and compliance pathways. It should be read as an exploratory evidence-to-law screening analysis, not a definitive wind-resource assessment, turbine-output model, capacity-factor estimate or grid-dispatch simulation.