The company behind an innovative blade inspection concept that combines drones flown from ships with artificial intelligence is looking at similar services for other parts of an offshore wind turbine
At the end of January 2019, EWPL Ocean confirmed it has been awarded a contract to undertake a full-scope offshore blade inspection and damage assessment on an as yet unnamed offshore windfarm on behalf of Dutch utility Eneco.
The company did not provide details about which windfarm the contract was for or provide details about the value of the contract or its duration, but Eneco owns two offshore wind projects in the Dutch sector of the North Sea, 129-MW Eneco Luchterduinen and 120-MW Prinses Amaliawindpark.
The latest deal is important because it confirms commercial acceptance of the innovative blade assessment concept developed by EWPL Ocean, a partnership between Esvagt and Wind Power LAB to provide operations and maintenance (O&M) services for offshore windfarms. It could be one of many such contracts for EWPL Ocean, which is already considering expanding the range of cost-saving services it offers asset owners in the offshore wind industry and has undertaken a number of blade inspections covered by non-disclosure agreements.
The companies launched their blade assessment service in 2018. Drones flown from vessels owned and operated by Esvagt will provide high resolution photography to which artificial intelligence techniques will be applied by Wind Power LAB to provide asset owners with a detailed report and analysis of blade condition and repairs that may be needed.
Speaking at the 2019 OWJ Conference in London in early February, EWPL Ocean chief executive Anders Ropke said the company’s business strategy brings together two concepts that are becoming increasingly important in the offshore wind industry: using unmanned aerial vehicles or drones as they are commonly known, and digitalisation. The aim is to industrialise offshore windfarm inspection and bring about significant cost reduction. Inspecting turbine blades is expensive, laborious and can be an imprecise process that requires good weather and specialist personnel.
Mr Ropke highlighted that one of the key advantages of the EWPL Ocean concept is that, apart from removing humans from the equation, the company can undertake blade inspections in winter and provide asset owners with a detailed report on which to base maintenance campaigns in summer. This greatly reduces the number of ‘access events’ required to inspect blades, reduces costs and enhances safety because windfarm technicians need only access turbines with blades in need of attention.
Mr Ropke said the drones flown from Esvagt’s vessels were robust unmanned aerial vehicles able to operate in wind speeds of up to 30 m/second. “We can finalise a maintenance campaign in around a quarter the time it would normally take,” he told delegates at the OWJ conference. “Once repairs have been undertaken in the summer months, when weather conditions allow for ease of access, we can conduct another campaign in autumn to validate the repairs.”
Artificial intelligence techniques developed by Wind Power LAB are used by the EWPL Ocean team for defect detection. Mr Ropke said AI techniques are applied to around 500 images of every turbine taken during an inspection campaign.
“Our core service is to provide blade defect assessments to our customers that form the basis of repair recommendations. This is true data-driven maintenance,” said Mr Ropke. “Our defect assessment reports cover the entire surface of a blade; details on defects are categorised and are available from the report we produce after a survey is carried out. Working this way is much less expensive, faster and more precise than conventional visual inspection. We provide intelligent asset management rather than annual inspections of the type that are usually used.”
Mr Ropke told the conference that EWPL Ocean is already looking at providing a range of complementary services to blade inspection. These could include inspecting wind turbine towers for corrosion and nacelle inspections. In due course, the company could also offer underwater services using unmanned underwater vehicles to assess the state of foundations.