Robotic Inspection: An overview of their use in supporting safer & more productive Wind assets.
Author: Andrew Johnston
Wind power's future development represents a significant opportunity to provide low-carbon energy all over the world. Over the next three years, Europe is expected to install an average of 23 GW of new wind farms per year, for a total of 116 GW. Wind turbines have undergone design changes to become larger, better, and more durable, improving the sector's competitiveness. There have been reports, for example, of 120m-long blades and offshore wind farms being installed in harsher environments further out at sea.
Energy asset operators are working to improve turbine uptime and productivity while reducing or eliminating safety risks and addressing maintenance and repair costs.
However, inspection and maintenance of critical offshore assets in the offshore renewable energy, oil and gas, or other industrial sectors can be expensive, with approximately 65% of costs being operational. It's not surprising that the industry is looking to adopt and collaborate with robotic and autonomous technologies to mitigate some of these impacts.
Picture: Innovair Engineer Inspecting a Offshore Wind Turbine Monopile by Drone
How are robotics being used?
Existing solutions are already saving the wind industry money by improving efficiency in routine and
non-routine inspections. Drones and robots can help operators and owners collect data to assess the current state and operational performance of wind farms while also providing information for maintenance decisions and reducing downtime and costs. All of these factors contribute to a wind farm's and its associated assets' operational lifespan being extended.
More than 80% of the cost of offshore wind operations and maintenance is a function of accessibility
Furthermore, the technology and processes being used are significantly reducing the number of mobilisations required for inspection campaigns, resulting in a significant reduction in the carbon footprint of these operations by using fewer vehicles or SOV/CTV time. According to the Crown Estate, more than 80% of the cost of offshore wind operations and maintenance is a function of accessibility, such as getting technicians to sites via SOV or CTV during tasks such as inspection. The ability to reduce the number of mobilisations through the use of robotics has clear financial benefits for operators as well as a reduction in the carbon footprint of works.
Robotics and autonomous solutions (RAS) have become an essential part of wind farm operations and maintenance processes for understanding the state of the wind farm and efficiently planning required repairs and maintenance. These solutions can be applied to wind assets throughout their entire lifecycle, including installation, end-of-warranty inspections, in-service, and decommissioning. Some RAS applications in the wind industry are detailed below.
The incorporation of autonomous technologies provides significant advantages for repeatable inspection data collection, such as increased safety, efficiency, and reduced overall environmental impact. One example is performing blade inspections with autonomous drones, which use onboard LiDAR sensors to navigate around blade and turbine components and capture accurate and high-quality repeatable data sets for each blade inspected. This data can be consolidated on cloud-based portals, allowing stakeholders to easily access and collaborate with their blade assets and repair teams. When managing a large portfolio of wind turbines, having all inspection data organised by severity at your fingertips can save a lot of time.
Drone inspection adds significant value by lowering risk and costs, particularly when working at heights. By replacing traditional methods such as rope access with drones, inspection time per turbine is reduced, resulting in less production downtime. For example, shutting down a 6 MW wind turbine generator (WTG) can result in a loss of revenue of approximately £1,000 per hour. A rope access team can inspect one turbine per day, taking the turbine offline for up to 8 hours, whereas a drone team can inspect a turbine in less than an hour, saving up to 90% of the revenue lost due to downtime.
Picture: Innovair completing Autonomous Blade Inspection on an offshore wind turbine.
Although most blade inspections are performed from the outside, it is also critical to inspect the blades internally, as the internal condition of a blade may differ significantly from the external condition and, if left untreated, can lead to undetected damages or failures. Inspecting the inside of a blade is difficult because it requires a technician to enter the relatively small, confined space inside the blade through the hub. Remote inspection technologies (RITs) like confined space drones or robotic crawlers provide a safe alternative for inspecting blade internals.
Lightning protection systems (LPS) are an important safety component on turbine blades, and they are typically inspected or tested using traditional methods such as rope access or lifting aids. Contact drones equipped with specialised probes, on the other hand, can now easily complete this task, increasing the number of LPS systems that can be checked in a shift. When combined with external and internal visual inspections, this provides a thorough examination of the blade to aid decision-making.
Due to harsh environments, such as the splash zone, inspecting offshore wind farms can be difficult. In these conditions, conventional techniques like rope access and diving might be too risky, time-consuming, and expensive when compared to alternate techniques.
Operators, who must inspect a variety of assets including foundations, monopiles, jacket structures on substations, and more, face a significant challenge in automating the method for accessing target components and delivering cost-effective non-destructive testing (NDT) campaigns on assets at heights or subsea.
Innovations like magnetic crawlers and climbing robots can be used in subsea as well as dry environments to support operations that are quicker, more effective, and safer. These systems can be remotely controlled, require little in the way of resources or platform space, and enable personnel to work safely without the need for a support vessel.
These robots can also carry out tasks like cleaning marine growth, scanning the seabed, and weld inspections in addition to visual and NDT inspections.
Picture: Offshore Wind Turbine Monopile Structure with marine growth
The next generation of subsea hybrid autonomous underwater vehicles (HUAVs) are already making a splash in the energy sector. These intelligent vehicles operate from docking stations and carry out various routine and non-routine tasks underwater. They were created with "subsea residency" in mind. Being a "resident," where the vehicle stays docked or connected to a subsea docking station for charging and data transfer, will provide carbon-zero solutions for survey, inspection, maintenance, and repair that will enhance sustainability, effectiveness, safety, and decision-making for subsea operations.
HAUVs are often designed to be more flexible and adaptable than other types of autonomous underwater vehicles (AUVs), as they can switch between autonomous and remotely controlled modes depending on the needs of the mission. This allows them to operate in a wider range of environments and perform a greater variety of tasks.
The industry will save a lot of money by implementing this technology and promoting a strong marine autonomy solution, which will also lower the costs and environmental impact of topside vessels.
Picture: ROV inspecting an offshore subsea structure
Summary - The Future is remote
The UK is a major player in onshore wind and currently leads the world in offshore wind capacity installed. The widespread use of robotic and autonomous systems (RAS) technology has already and will continue to have a positive impact on the wind industry.
RAS is an area of innovation that is here to stay because operators are always looking for new ways to improve performance and cut down on the amount of time technicians spend offshore. Robotic systems also play a crucial role in reducing risks to personnel health and safety, completing labour-intensive inspection tasks in challenging environments. Throughout the lifecycle of wind farms and their assets, RAS will continue to contribute to safer assets and improved performance.
A message from the author
"Thanks for taking time to read this blog on robotic inspection. The collective knowledge and expertise within the Innovair team has been developed during hundreds of inspection work scopes for some of the largest energy companies across the globe.
Reliable, innovative and experienced, we hope to become your go-to team for trusted inspection advice, support & solutions.
If you would like to organise a discovery session, get in touch below."
Andrew Johnston BEng, MInstNDT LEP