We are sure many of you have come across the really tragic incident that happened in the Netherlands in 2013, where two young engineers died when a fire broke out below the wind turbine they were working maintenance on.
According to news reports, four technicians were at a height of 67 metres in a gondola next to the wind turbine when the flames overwhelmed them. They could not escape in time.
One of them jumped and was found in the field next to the turbine, while the second victim was trapped in the blazing flames. Two other technicians were able to reach the ground safely during a rescue operation carried out by a special firefighter team.
People were still feeling their way around drone technology during that time, and a few years later, we think it is good that the smart people in the industry have figured out the best ways to these offshore jobs safer.
With the world pivoting away from fossil fuels for their unfriendly effects on global warming, renewable energies are gathering momentum and organisations are setting up more offshore wind energy generators with the passage of time.
It is therefore a really welcome development that such energy companies are adopting drone deployment in an increasing number of operations, which include data collection, monitoring and cargo delivery.
One such company is Vattenfall, a Swedish multinational energy company that – beyond its home base – generates power in Denmark, Finland, Germany, the Netherlands and the United Kingdom.
The company has now introduced drone operations for its offshore power generation sites, and the below article – gleaned from Reve - explains how they are going about it.
Artificial intelligence combined with drones offers significant advantages for offshore wind. Advanced AI technologies not only enhance safety and efficiency of offshore activities but also reduce emissions and lower operational costs.
AI-equipped drones perform complex inspections, maintenance, and cargo delivery, enabling wind turbines to perform at their peak.
New applications and capacities of drones frequently surpass existing regulations, requiring ongoing adjustments in legislation.
For instance, regulations for Beyond Visual Line of Sight (BVLOS) operations, where the operator has no direct visual sight of the drone and other airspace users, are evolving. Similarly, autonomous vessels must comply with the regulations set by the International Maritime Organisation (IMO) to guarantee safety and environmental protection.
AI-equipped drones can work independently, find their required flight path and avoid obstacles. Aerial drones are used in Vattenfall’s offshore activities for the inspection of wind turbine blades and are being tested for spare part delivery, while unmanned vessels are used for seabed surveys and for the inspection of foundations below the water level.
Some drones are piloted by a nearby pilot, while others are piloted from a remote-control centre, which can even be located in another country.
Data and images collected by inspection drones are merged and analysed by machine learning algorithms to detect cracks, erosion, dirt, and other anomalies. The data is stored in the cloud, categorised by severity, compared with historical data and finally reports are generated for maintenance teams. This enables proactive maintenance planning, which can prevent major repairs.
Testing drone technologies
By contributing technical expertise, Vattenfall is supporting the AIRTuB-ROMI initiative in the Netherlands, to improve offshore wind maintenance using in-blade monitoring and drone-crawler robots.
The project, supported by the Dutch Ministry of Economic Affairs and an industry-academic collaboration, will evaluate three different sensor technologies in turbine blades.
When the sensors detect an anomaly, AI algorithms help to predict the potential damage and its location. A drone-crawler is automatically deployed from its offshore docking station within the wind farm to perform a further inspection.
“After take-off of the drone, it will autonomously capture high-resolution images of the blades from different angles,” explains Tomas Jansen, product manager O&M Automation for Vattenfall Offshore Wind in Germany.
“The drone will then land on the blade to conduct an ultrasonic scan of the potentially damaged area, giving us complete information of the structural health of the blade. With this detailed information, the maintenance team can initiate repair planning as needed.”
Spare parts delivery
Thanks to advanced sensors and AI-powered software, cargo drones can fly safely in complex offshore environments, avoid obstacles and adapt to changing weather conditions.
They can transport materials and equipment from a service operation vessel (SOV) to wind turbines, reducing the need for vessels to go back and forth. The use of an unmanned air vessel (UAV) speeds up the delivery of materials, saves time, and reduces carbonemissions by eliminating the need for a crew transfer vessel (CTV).
This innovation was recently tested in Vattenfall’s offshore wind farms DanTysk and Sandbank in the German North Sea. A collaboration between offshore service provider Ampelmann, Dutch Applied Scientific Research Institute TNO, and Vattenfall demonstrated the use of cargo drones in the offshore environment.
“The innovation we showcased included using UAVs for rapid deliveries and pre-loading spare parts and tools to the turbine’s nacelle,” said Roddy Douglas, an automation engineer at Vattenfall Offshore Wind in the UK, who was involved in the test.
“This is especially beneficial when a part is needed unexpectedly, allowing the on-site team to work efficiently, without waiting for a ship, minimising downtime and revenue loss at wind turbine generators. For sites closer to the coast, cargo can be transported directly from the service centre, where operators use automated drones to deliver essential cargo even in challenging weather conditions.”
Underwater inspections and surveys
Uncrewed vessels and remote-controlled drones enhance employee safety during inspections at sea and ensure environmentally friendly operations.
During installation works at offshore wind farm Hollandse Kust Zuid in the Dutch North Sea, Vattenfall deployed Blue Essence, a twelve-metre-long uncrewed surface vessel equipped with an electrical remotely operated vehicle (eROV) for inspections and seabed mapping.
Developed in close collaboration with partner Fugro, this innovation reduces the reliance on crewed vessels, speeds up inspections and minimises environmental impact. The uncrewed vessel with eROV features advanced sensors, sonar, and high-definition cameras that provide real-time data on cable and foundation conditions.
Both the uncrewed vessel and eROV can operate 24/7, withstand wind speeds of up to 38km per hour (wind force 5), and handle wave heights of up to one and a half metres. They are remotely operated from Fugro’s control rooms in Aberdeen, Scotland.
As offshore wind projects move further into the sea, the advantages of remote-controlled vessels become increasingly significant. Initial operations have shown that uncrewed vessels emit approximately 95 percent less CO2 compared to traditional survey vessels. Additionally, their smaller size reduces the impact on marine life.
Fit for the future
Upcoming developments in AI are set to significantly improve the capabilities of drones in offshore wind operations. With more advanced AI algorithms, drones could become even more autonomous, capable of making independent decisions during complex inspections and early-stage damage detection without human intervention.
“AI-equipped drones have the potential to free up valuable offshore working time,” Jansen said.
“Given the scarcity of skilled technicians in the offshore wind industry, this is an important advantage. The drones can, for example, perform recurring lightning protection tests on large wind farms, allowing technicians to focus on solving specific issues identified by the drones.”
Roddy Douglas underscores the positive outcomes of tests in the offshore environment with cargo drones and AI-technology; “The results of our recent demonstrations in our wind farms provide a glimpse into the future of automated and intelligent offshore transport solutions and we have already planned additional tests.
“In collaboration with our partners, we are dedicated to further exploring promising developments to meet the increasing demand for wind energy, both now and in the future.”