CleanWinTur: An ultrasonic system for anti-fouling and condition monitoring of offshore wind turbines
As existing offshore wind turbines age and new OWTs are situated in deeper waters and further from the shore, maintenance costs become increasingly important in determining OWT lifetime and achieving levelised cost of energy (LCoE) targets set by the government. In particular, dealing with biofouling and corrosion in OWTs' substructure and splash area through traditional means (i.e. divers, coatings, and ROVs) becomes increasingly challenging, costly, dangerous and ineffective. CleanWinTur will address both issues by developing an ultrasonic system that performs continuous condition monitoring and effective anti-fouling thereby enabling the implementation of predictive and/or condition-based maintenance and reduce maintenance costs by 50%. As a result CleanWinTur will help reducing OpEx by 30% while enabling CapEx reductions by allowing less conservative substructure designs. CleanWinTur has therefore the potential of saving the industry millions while generating £38,7M in profits for the consortium and creating 387 jobs 5 years after commercialisation. The project is backed by a prestigious consortium including NDT Consultants, the European Marine Energy Centre, 3-Sci, InnotecUK, Alpha Electro Technology and Brunel University London.
Offshore wind energy has been instrumental in reducing greenhouse gas emissions and rendering the UK less dependent on imports to cover its energy needs. As such, large investment programmes and favourable legislation have been driving growth in the sector with overall capacity doubling every five years, a trend that is set to continue by 2030. However, offshore wind energy costs remain high and the increasing depth and distance from the shore continue to drive maintenance costs up, particularly those associated to the substructure, limiting the sector's growth potential. In particular, dealing with marine growth and corrosion through traditional means (i.e. divers) becomes increasingly costly, challenging, dangerous, and ineffective.
CleanWinTur will automate this process with a permanently installed system that uses power ultrasound to prevent marine growth on the substructure while periodically monitoring the integrity of the structure. This way manual inspection and maintenance will be cut to half, reducing respective costs and dangers. This will eventually translate to a 7% decrease on energy costs, helping to boost offshore wind growth.
CleanWinTur will combine cutting-edge innovative ultrasonic technologies to improve OWT resilience and lower overall lifetime costs. The aim is to further develop and demonstrate a novel anti-fouling, defect-detection system that remains effective in diverse marine environments, targeting an operational lifetime of at least 10 years. The technical approach consists of: Permanently attached ultrasonic transducers on the surface of the substructure, emitting ultrasonic waves at different frequencies (30-40 kHz for anti-fouling and 20-100 kHz for condition monitoring).
i) Within the anti-fouling mode, ultrasound will prevent micro-organisms growth by creating acoustic cavitation on the outer surface of the substructure.
ii) For the condition monitoring mode, the system will monitor and detect changes in wall thickness (with accuracy down to 5% cross sectional area loss) indicating the effects of corrosion or scour across the substructure.
An autonomous system drawing power directly from the OWT using custom-made electronics for low cost and low power consumption (targeting 0.1 kW/m2 and assuming average width 4.5m, depth 20m and a 6MW OWT, consuming <1% of the turbines power output). A non-toxic solution to bio-fouling prevention, effective for static offshore structures (in contrast to coatings). Crucially, the CleanWinTur ultrasound operating modes are non-destructive unlike mechanical methods like hosing and helps protect cathodic anticorrosion systems which often get damaged by biofouling.
- Innovative Technology and Science Limited
- N.D.T. Consultants Limited
- REECE Innovation Centre Limited
- 3-Sci Limited
- The European Marine Energy Centre Limited
- E.On Climate & Renewables UK Limited
- Brunel University London