WILLOW | Wholistic and Integrated digital tools for extended Lifetime and profitability of Offshore Wind farms

Wind farms must deliver output power following the needs of grid operators, as electricity generation has to match demand in real time. This implies producing less power than available. Optimally matching supply to demand and the impact of these actions on the equipment are complex, while insights are lacking. The European project WILLOW aims to achieve an integrated system that will provide a health aware curtailment strategy to the offshore wind farm operators.

Context

In the day-ahead market, wind energy production is maximised by adjusting the output of other dispatchable electric sources to accommodate the variability of wind power. However, this approach has been questioned. Instead, wind farms (WFs) should deliver a commanded output power that meets the grid operator's needs, rather than always producing the maximum possible power. This means wind farms may need to downregulate and produce less power than they are capable of generating.

How is it done today? 

Today, wind farms manage power output regulation primarily through two methods:

• Stopping a few turbines: a select number of turbines are stopped, allowing the remaining turbines to operate at maximum power.
• Downregulating each turbine: each turbine is downregulated by the same amount, which can negatively impact fatigue life.

Both methods aim to balance power production with grid demands, but they come with distinct operational challenges and potential drawbacks. There has been a lack of success in implementing new decision-making schemes for wind farm regulation due to several factors:

• Complexity of component degradation and grid integration: the intricate nature of managing wear and tear on wind farm components while ensuring seamless integration with the grid poses significant challenges.
• Offshore degradation rates: offshore wind farms face additional degradation issues, including:
  • Corrosion: increased moisture and salinity accelerate corrosion of components.
  • Additional loads: waves, tides, and currents impose extra mechanical stress, further complicating maintenance and operation.

Objectives

The project aims to develop open-source, data-driven tools to reduce operational energy costs, increase wind farm output and evaluate operational risks. By introducing advanced digital and physical tools, operators will make better-informed decisions for optimising wind farms, extending their lifetime, and planning decommissioning. These innovations will help reduce the ‘Levelised Cost of Energy’ (LCOE) by extending the ‘Remaining Useful Lifetime’ (RUL) of wind farm substructures, aligning with SET Plan targets.

Expected impacts

• Lower maintenance costs – A reduction of 50% on the inspection costs
• Optimised design & operation life - 20% of lifetime extension in wind farms designed with 25 years of lifetime
• Environmental impact - Expectation of reducing noise pollution by 4%.
• Levelised cost of energy (LCOE) - Up to 10% reduction of LCOE, between 3.5 and 4.5€/MWh

Approach

Global Structural Health Monitoring (SHM) integrates loads, accelerations, images and thickness losses, to assess fatigue, pitting corrosion and coating degradation. This approach utilises both physical and virtual sensors combined with machine learning (ML) techniques. By combining SCADA and SHM data with physical models and ML methods, advanced prognosis tools can predict the consumed lifetime and remaining useful life of wind farm components. Additionally, a decision-making support tool aids in smart power dispatch during curtailed conditions and optimises operation and maintenance (O&M) scheduling. This comprehensive strategy ensures enhanced reliability, efficiency, and longevity of wind farm operations.

Target group

Industry: wind farm operators (WFOs) and electric utilities as final users, electricity network operators (TSOs, DSOs) which will provide better informed curtailment set points to WFOs, manufacturers of offshore wind structural components, suppliers of windfarm controllers, companies providing services and products for wind turbine and windfarm O&M.

Policy makers

RTOs: research centres, universities, to further develop the tools and provide the services

Society: public awareness.

Funding

WILLOW is fully funded by the European Union
EU Grant: ~5.8 M€ (100% funding ratio)

• Framework
  • Call: HORIZON-CL5-2022-D3-03 (Sustainable, secure and competitive energy supply) 
  • Topic: HORIZON-CL5-2022-D3-03-04 
  • Type of Action: HORIZON-RIA

Sirris expertise

Access to offshore test site
Sirris has a standing collaboration with the Blue Accelerator for the performance of offshore testing. We have a data acquisition system on site, as well as the experience and collaboration protocols in place to perform offshore exposure tests.

Coating degradation Lab
Sirris has a laboratory dedicated to accelerated coating degradation tests (salt spray, QUV, humidity chambers, cyclic testing, immersion testing), as well as coating application and evaluation (coating hardness, dolly pull-off, scratch testing, electrochemical testing).

Corrosion Lab
Sirris has a laboratory dedicated to accelerated corrosion testing (electrochemical testing, immersion, salt spray, pitting corrosion tests, chemical laboratory) and corrosion evaluation (optical and electron microscopy, SEM-EDX, penetrant testing, pit depth measurements).