Periodic Reporting for period 1 - ShareWind (Shared anchors for floating wind turbines)
Reporting period: 2023-07-01 to 2025-06-30
Floating offshore wind energy is a critical component of the EU’s strategy to achieve climate neutrality, as outlined in the European Green Deal and the SET Plan. However, the high cost of current technologies hinders its widespread adoption. Mooring systems, which secure floating turbines to the seabed, account for a significant portion of these costs. ShareWind project was designed to address this economic barrier by exploring a more efficient anchoring solution: shared anchors.
The overall objective of the project was to reduce the cost and environmental footprint of floating offshore wind farms by providing the scientific and engineering foundation for the use of shared anchors in clay seabeds. The project aimed to fill a critical gap in the state of the art, as there was previously no experimental data on how shared anchors perform under the complex, multidirectional loads generated by multiple floating turbines.
The project's pathway to impact was structured around three core activities:
- Defining realistic conditions for loads, anchor geometry, and seabed characteristics.
- Conducting physical model tests in a geotechnical centrifuge to generate benchmark - data on anchor performance.
- Developing and validating advanced numerical models to create reliable design guidelines for industry.
The expected impact of ShareWind is twofold. Technologically, it de-risks a key innovation in offshore wind, with the potential to reduce mooring costs by approximately 16%. Societally, by making renewable energy more cost-competitive, the project contributes directly to Europe's energy transition, enhances energy security, and supports the long-term goal of a sustainable economy. The project’s commitment to Open Science ensures that its results will be widely disseminated, fostering further innovation across academia and industry.
The overall objective of the project was to reduce the cost and environmental footprint of floating offshore wind farms by providing the scientific and engineering foundation for the use of shared anchors in clay seabeds. The project aimed to fill a critical gap in the state of the art, as there was previously no experimental data on how shared anchors perform under the complex, multidirectional loads generated by multiple floating turbines.
The project's pathway to impact was structured around three core activities:
- Defining realistic conditions for loads, anchor geometry, and seabed characteristics.
- Conducting physical model tests in a geotechnical centrifuge to generate benchmark - data on anchor performance.
- Developing and validating advanced numerical models to create reliable design guidelines for industry.
The expected impact of ShareWind is twofold. Technologically, it de-risks a key innovation in offshore wind, with the potential to reduce mooring costs by approximately 16%. Societally, by making renewable energy more cost-competitive, the project contributes directly to Europe's energy transition, enhances energy security, and supports the long-term goal of a sustainable economy. The project’s commitment to Open Science ensures that its results will be widely disseminated, fostering further innovation across academia and industry.
The project successfully executed its research plan, which was structured across several interconnected work packages, to investigate the performance of shared anchors for floating offshore wind turbines.
The initial phase of the project established the foundational parameters for the entire study. This involved a comprehensive analysis of load conditions, suitable anchor geometries for clay seabeds, and anchor installation considerations. This work, conducted in collaboration with the Norwegian Geotechnical Institute (NGI), resulted in a detailed set of prototype conditions that ensured the subsequent experimental and numerical studies were representative of realistic offshore environments.
The core of the experimental work was an extensive physical modeling campaign using the geotechnical centrifuge at Université Gustave Eiffel. A specialized experimental setup was designed to simulate the complex, multidirectional loading that shared anchors experience. A series of four centrifuge tests were conducted on 12 anchor models installed in reconstituted clay beds that replicated offshore soil conditions. This campaign produced a unique, high-quality dataset on the soil-anchor response under cyclic loading. From this data, experimental failure envelopes were developed, defining the load combinations that lead to soil failure and providing crucial stability contours for anchor design.
In parallel, numerical simulations were conducted using the Finite Element Method (OpenSees) to model the behavior of the anchors. These numerical models were carefully calibrated and validated against the high-quality data obtained from the centrifuge experiments. A significant achievement was the development of a fully validated set of numerical models capable of accurately predicting the stresses and deformations of the soil-anchor system. The project also implemented an innovative methodology using mobile photogrammetry to create Digital Twins, or virtual replicas, of the centrifuge models, enhancing the visualization and analysis of the experiments.
Finally, the validated numerical models were used to conduct extensive parametric analyses. These simulations explored a wide range of variables, including different anchor geometries and soil conditions. This work led to the project's main practical outputs: design guidelines and refined failure envelopes for shared anchors. These results have been consolidated into two peer-reviewed scientific articles, which are currently under review. The load data representative of shared anchor systems was also processed and made available in an open repository for use by other researchers and engineers.
The initial phase of the project established the foundational parameters for the entire study. This involved a comprehensive analysis of load conditions, suitable anchor geometries for clay seabeds, and anchor installation considerations. This work, conducted in collaboration with the Norwegian Geotechnical Institute (NGI), resulted in a detailed set of prototype conditions that ensured the subsequent experimental and numerical studies were representative of realistic offshore environments.
The core of the experimental work was an extensive physical modeling campaign using the geotechnical centrifuge at Université Gustave Eiffel. A specialized experimental setup was designed to simulate the complex, multidirectional loading that shared anchors experience. A series of four centrifuge tests were conducted on 12 anchor models installed in reconstituted clay beds that replicated offshore soil conditions. This campaign produced a unique, high-quality dataset on the soil-anchor response under cyclic loading. From this data, experimental failure envelopes were developed, defining the load combinations that lead to soil failure and providing crucial stability contours for anchor design.
In parallel, numerical simulations were conducted using the Finite Element Method (OpenSees) to model the behavior of the anchors. These numerical models were carefully calibrated and validated against the high-quality data obtained from the centrifuge experiments. A significant achievement was the development of a fully validated set of numerical models capable of accurately predicting the stresses and deformations of the soil-anchor system. The project also implemented an innovative methodology using mobile photogrammetry to create Digital Twins, or virtual replicas, of the centrifuge models, enhancing the visualization and analysis of the experiments.
Finally, the validated numerical models were used to conduct extensive parametric analyses. These simulations explored a wide range of variables, including different anchor geometries and soil conditions. This work led to the project's main practical outputs: design guidelines and refined failure envelopes for shared anchors. These results have been consolidated into two peer-reviewed scientific articles, which are currently under review. The load data representative of shared anchor systems was also processed and made available in an open repository for use by other researchers and engineers.
ShareWind project has produced results that advance the state of the art in offshore geotechnical engineering, providing a new foundation for the design of cost-effective mooring systems for floating wind farms.
The project's most significant achievement is the creation of the first-ever experimental dataset on the performance of shared anchors in clay seabeds under complex, multidirectional loading. Prior to this project, no such data existed, forcing engineers to rely on conservative and unverified assumptions. This high-quality dataset, now openly available, serves as a crucial benchmark for the entire scientific and industrial community. It allows for the calibration and validation of advanced numerical models with a level of confidence that was not previously possible.
Building on this unique dataset, the project developed and validated a set of advanced numerical models capable of accurately predicting anchor behavior. This provides the industry with a reliable tool to optimize anchor design, moving beyond theoretical models to simulations grounded in physical evidence. Another key innovation was the integration of 3D photogrammetry to create Digital Twins of the physical experiments, offering new possibilities for analyzing soil-anchor interaction and enhancing research methodologies.
The primary potential impact of these results is economic. By enabling the confident use of shared anchors, the project's findings can reduce the capital expenditure on mooring systems for floating wind farms by an estimated 16%. This significant cost reduction makes floating offshore wind a more competitive energy source, directly supporting the EU's Green Deal objectives and accelerating the transition to renewable energy.
Key Needs for Further Uptake and Success
To ensure the successful uptake of the project's findings and to move the technology from its current Technology Readiness Level (TRL) 4 towards commercial application, the following steps are needed:
- Further Research and Demonstration: While the project has validated the concept in a laboratory environment, further research is needed to investigate performance across a wider range of soil conditions and anchor types. The next logical step would be to advance to a higher TRL through a large-scale demonstrator or pilot project in a real sea environment.
- Commercial Partnership: Stronger collaboration with industrial partners, including offshore wind farm developers, engineering consultancies, and anchor manufacturers, is required. These partnerships will facilitate the transfer of knowledge and ensure that the project’s outputs are directly applied in the design of the next generation of commercial floating wind farms.
The project's most significant achievement is the creation of the first-ever experimental dataset on the performance of shared anchors in clay seabeds under complex, multidirectional loading. Prior to this project, no such data existed, forcing engineers to rely on conservative and unverified assumptions. This high-quality dataset, now openly available, serves as a crucial benchmark for the entire scientific and industrial community. It allows for the calibration and validation of advanced numerical models with a level of confidence that was not previously possible.
Building on this unique dataset, the project developed and validated a set of advanced numerical models capable of accurately predicting anchor behavior. This provides the industry with a reliable tool to optimize anchor design, moving beyond theoretical models to simulations grounded in physical evidence. Another key innovation was the integration of 3D photogrammetry to create Digital Twins of the physical experiments, offering new possibilities for analyzing soil-anchor interaction and enhancing research methodologies.
The primary potential impact of these results is economic. By enabling the confident use of shared anchors, the project's findings can reduce the capital expenditure on mooring systems for floating wind farms by an estimated 16%. This significant cost reduction makes floating offshore wind a more competitive energy source, directly supporting the EU's Green Deal objectives and accelerating the transition to renewable energy.
Key Needs for Further Uptake and Success
To ensure the successful uptake of the project's findings and to move the technology from its current Technology Readiness Level (TRL) 4 towards commercial application, the following steps are needed:
- Further Research and Demonstration: While the project has validated the concept in a laboratory environment, further research is needed to investigate performance across a wider range of soil conditions and anchor types. The next logical step would be to advance to a higher TRL through a large-scale demonstrator or pilot project in a real sea environment.
- Commercial Partnership: Stronger collaboration with industrial partners, including offshore wind farm developers, engineering consultancies, and anchor manufacturers, is required. These partnerships will facilitate the transfer of knowledge and ensure that the project’s outputs are directly applied in the design of the next generation of commercial floating wind farms.