Presentations

Abstract

The Netherlands has set ambitious targets for offshore wind energy, aiming for 21 GW installed capacity by 2032 as part of its transition to a carbon-free energy supply. Achieving these goals requires a large expansion of wind energy power plants across the North Sea, for which robust wind resource assessment and a deep understanding of wind conditions across the Dutch North Sea is needed. Since 2014, TNO has been conducting a long-term, continuous measurement campaign at strategically chosen offshore locations on behalf of the Dutch Ministry of Climate Policy and Green Growth. The measurement program entails state-of-the art lidar technology deployed on the five offshore platforms Lichteiland Goeree (LEG), Europlatform (EPL), K13-A, L2-FA-1 and F2-A-Hanze. This selection of platforms provides a broad spatial coverage of the Dutch North Sea, especially at locations earmarked for future wind farm development. The measurement data is publicly accessible and valuable for wind farm developers and researchers. This study presents an overall analysis of wind resource characteristics between 2014 and 2025 derived from high-resolution lidar data to establish long-term wind speed trends, and quantify spatial correlation and variability across the North Sea. It is also illustrated by case studies and current developments in the wind energy sector what are the insights gained of the long-term measurement program, both as a wind resource assessment method prior to wind farm development, but also for its monitoring potential during the operational lifetime of installed wind farms. When continued accordingly, the long-term data set will be able to shed a light on the effect of installed wind farms on the wind energy resource at the North Sea. This can be further used to validate wake models. A case study used to illustrate this is the updated investigation of wake effects from the Borssele offshore wind farm, operational since 2020. By comparing wind speed ratios at EPL and LEG before and after Borssele’s commissioning, and validating with TNO’s in-house wake simulation software FarmFlow, the study quantifies wake-induced wind speed reductions of up to 9% at distances of 26–43 km away from the wind farm. The annual average wind speed reduction due to wakes is estimated at 0.03 m/s for EPL and 0.05 m/s for LEG, corresponding to 0.35% and 0.51% of the mean wind speed, respectively. This example only looks at one specific wind farm cluster but sets an example for what further studies can be enabled by the measurement data. This contribution offers valuable insights for developers, policymakers, and researchers, demonstrating how comprehensive measurement and analysis can stimulate the success of offshore wind energy deployment in the North Sea. Furthermore, the availability of high-quality wind data also opens new opportunities for research in fields such as ecology, climate studies, and environmental impact assessment. TNO will share their lessons learned from the measurement program so far and highlight its future perspectives.