
Floating offshore wind
Floating offshore wind sector: a market with promising development
Floating offshore wind technology makes it possible to envisage the deployment of offshore systems in areas inaccessible to bottom-fixed wind turbines due to water depth of more than 60 m. Its proven efficiency also for shallow waters makes it a competitive alternative to the use of piles or gravity foundations. Developing this technology would allow better exploitation of offshore wind fields. The first pilot farms show an average load factor of 65% to 70% when the bottom-fixed wind turbines have a load factor of 40-45% offshore and 22% onshore. The distance from the coast offers a more constant wind with a higher average speed, but represents a strong constraint for the export of the power produced. The market is emerging, with development supported by several pilot farms, some of which are already in operation. Knowing that 80% of the offshore wind energy available in Europe is located in depths suitable for floating technology and that the additional operating costs compared to bottom-fixed wind turbines are lower than expected, the sector anticipates very rapid development. This is confirmed by the performance of current prototypes, which is better than initially forecast.
Reliability and performance issues
The main challenges for the deployment of floating offshore wind sector in France and internationally are :
- The reliability of mobile systems over 20 to 25 years in a hostile marine environment,
- A gain in performance conditioned by the minimisation of production losses linked to floating structure movements,
- The reliability and robustness of the dynamic part of the power export cable,
- The integration of future commercial farms with existing marine activities,
- The setting up of an industrial sector and dedicated port areas,
- The construction of an installation and maintenance chain with adapted means,
- The economic attractiveness that requires achieving an average cost of energy produced that is competitive with other sources of decarbonated energy,
- Applicable regulations and the acceptability of projects that can cause significant delays that then limit the deployment of technologies.
In France, calls for tenders for four pilot farms were awarded in 2016. The first productions are expected in 2022. In the framework of the law on multiannual programming of energy published in 2020, the French State announces commercial farms to be awarded as early as 2021. These elements underline the need to provide rapid responses to the challenges of floating offshore wind sector.
Wind resource, system design and environmental impact
France Energies Marines contributes to providing solutions for the floating offshore wind sector, mainly through collaborative R&D projects that enable :
- Reducing uncertainties on the characterisation of wind resources and thus contribute to the optimisation of production (ARCWIND and CARAVELE projects);
- Better characterising the physical environment, particularly wave fields, while taking into account the impact of breaking waves on floating structures (DIME and DIMPACT projects);
- Evaluating mooring solutions that reduce investment costs while guaranteeing a system payback, thus increasing performance, and propose adapted design standards (POLYAMOOR and MONAMOOR projects);
- Improving the prediction of the service life of dynamic export cables and mooring lines in order to propose adapted monitoring solutions and optimise the maintenance plan and conservative design costs to cover uncertainties (OMDYN2, MHM-EMR, ABIOP+, POLYAMOOR and MONAMOOR projects);
- Optimising environmental, societal and economic impact studies by proposing original models integrating the ecosystem in the broadest sense to support the acceptability of projects (TROPHIK, APPEAL and WINDSERV projects);
- Supporting the choice of locations and future impact studies, in particular by proposing appropriate means and methods for data acquisition (GEOBIRD, ORNIT-EOF, ECOSYSM-EOF, SEMMACAPE and OWFSOMM projects);
- Studying the potential environmental effects of the systems by assessing the effect of electromagnetic fields from submarine cables (SPECIES project), passive acoustic monitoring of benthos (BENTHOSCOPE and BENTHOSCOPE2 projects) or the quantitative assessment of metals released into the marine environment from galvanic anodes (ANODE project).
Recommendations for the evolution of current standards
The various studies to which the Institute contributes aim to provide the sector with validated models, adapted measurement methods, representative data and recommendation reports based on recognised expertise. An ongoing project on biofouling (ABIOP+ project) thus provides decisive elements for the design of mooring lines and dynamic cables by qualifying and quantifying the growth of biocolonisation in the vicinity of future farms and measuring its effect on the behaviour of these critical components. The results of this project reinforce the confidence of developers in taking biofouling into account by proposing to standardise the characterisation protocol for this influential parameter. The work carried out as part of our dimensioning and in-service monitoring activity is conducted in the presence of certifying bodies and produces recommendations intended to develop current standards.
Photo credit: Naval Energies
Projects
In progress
APPEAL
Socio-ecosystemic approach to the impact of floating wind farms
In progress
CARAVELE
Wind characterisation for offshore renewable energies applications
Closed
MHM-EMR
Mooring health monitoring for offshore renewable energy systems
Closed
ABIOP
Accounting for biofouling through established protocols of quantification
In progress
ABIOP+
Consideration of biofouling using quantification protocols useful for engineering
Closed
ANODE
Quantitative evaluation of metals released into the marine environment from the galvanic anodes of ORE structures.
In progress
ARCWIND
Adaptation and implementation of floating wind energy conversion technology for the Atlantic Region
Closed
BENTHOSCOPE 2
Understanding and monitoring of ORE impacts on the benthic compartment via a measurement platform dedicated to passive acoustic
In progress
CASSIOWPE
Characterising the atmosphere and sea surface interactions for the deployment of offshore wind in the Gulf of Lion
Closed
COASTWAVE
High-resolution local analysis of wave and breaking variability from satellite imagery
In progress
COME3T
Committee of experts for offshore renewable energies environmental issues
In progress
DIME
Design and metocean: modelling and observations of extreme sea states for offshore renewable energies
In progress
DIMPACT
Design of floating wind turbines and impacts of energetic steep and breaking waves
In progress
DUNES
Dynamics of hydraulic dunes and impact on ORE projects
In progress
DYNAMO
Dynamic cable monitoring
In progress
ECOSYSM-EOF
Prefiguration of an observatory of marine ecosystems in interaction with floating offshore wind farms in the Gulf of Lion
In progress
ECUME
French working group on cumulative effects of ORE projects
Closed
EOLINK
Proof of concept for an innovative floating wind turbine
In progress
LIF-OWI
Environmental, socio-economic and technological challenges for life cycle assessments of offshore wind farms
Closed
LISORE
Innovative and cost-effective offshore substations for ORE by 2025
In progress
FOWRCE SEA
Future offshore wind research center at sea
In progress
GEOBIRD
Development of an innovative geolocation tag for seabirds
Closed
MEDSEA CHECKPOINT
Assessment of the Mediterranean observational data system for targeted applications
In progress
MONAMOOR
Monitoring of polyamide mooring lines
In progress
MOSISS
Monitoring strategies for innovative substations
Closed
OMDYN
Dynamic umbilicals for offshore renewable energies
In progress
OMDYN2
Dynamic umbilicals for floating marine renewable energies technologies - Phase 2
In progress
ORNIT-EOF
Prefiguration of an observatory of the Gulf of Lion birdlife in interaction with floating offshore wind farms
In progress
OWFSOMM
Offshore wind farm surveys of marine megafauna: standardisation of tools and methods for monitoring at farm scales
In progress
POLYAMOOR
Durable and flexible polyamide moorings for offshore renewable energies
In progress
SEMMACAPE
Monitoring and study of marine megafauna in wind farms by automatic characterisation
In progress
SPECIES
Subsea power cables interactions with environment and associated surveys
In progress
SUBSEE 4D
A digital twin to facilitate the operation of floating wind farms
Closed
TROPHIK
Modelling the role of offshore wind farms in modifying the functioning of coastal food webs and cumulative impact
Closed
VALARRAY
Optimisation software for tidal and floating offshore turbine arrays: state of the art, comparison and new tools specification
In progress
VALEF
Hydro-aero-elastic modelling of floating offshore wind turbines
In progress
WINDSERV
Towards a multi-model approach of indicators of ecosystem services
Services
Coordination and participation in expert panels on ORE
Design and in-service monitoring of power cables and moorings
Ecosystem approach of the impact of offshore wind farms
Marine life monitoring
MEMOFLOW, the permanent Mediterranean observatory for floating offshore wind sector
Offshore renewable energies farm optimisation
Resource and site characterisation
Training in the field of offshore renewable energies
Interlocutors

Guillaume Damblans
Design and Monitoring of Systems R&D Manager

Herveline Gaborieau
Head of Development and Valorisation
News

Published on 21/12/2020
COME3T, phase II
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Published on 03/12/2020
PhD – Analogue forecasting of geophysical systems
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Published on 11/12/2020
MEMOFLOW: deployment of new instruments
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Published on 10/12/2020
PhD – Biofouling and fatigue damages of mooring lines
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Published on 08/12/2020
Public report from the ANODE project
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Published on 16/10/2020
FEM Tribune – ORE integration webinar
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Published on 21/09/2020
FEM Tribune – Array optimisation webinar
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Published on 06/10/2020
FEM Tribune – Influence of biofouling webinar
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Published on 10/06/2020