Published on 12-Dec-2023

Exploring Autonomous Solutions for Wind Turbine Inspection and Repair

Exploring Autonomous Solutions for Wind Turbine Inspection and Repair

Table of Content


Introduction

The shift from manual to autonomous wind turbine inspection marks a pivotal change in renewable energy.

Nearthlab, a Seoul-based company, deploys AI-driven drones for Non-destructive Testing (NDT) of turbine blades and nacelles, reducing risks and downtime. 

These drones, equipped with AI and laser tech, swiftly capture over a thousand images, detecting defects efficiently.

In just 15 minutes, they accomplish what takes a day for human inspections, minimizing operational halts and improving productivity. 

This tech holds promise for offshore wind farms, eliminating risky human inspections.

Initiatives like the MIMRee project by OREC envision autonomous maintenance and repair.

Thales' mothership robot, aided by BladeBUG's blade crawler, exemplifies this cutting-edge collaboration in wind turbine maintenance. 

Despite concerns, this technology complements job growth in wind turbine services, allowing technicians to focus on tasks requiring human intervention while automated drones handle inspections. This convergence of robotics, AI, and autonomous systems signifies a transformative phase in renewable energy.

What is a Wind Turbine Inspection and Why is it Important?

Wind turbines are renewable energy structures harnessing wind to generate electricity.

They work by capturing wind energy through aerodynamic rotor blades, converting it into rotational motion that drives an internal generator to produce electricity.

As wind blows through the blades, it creates lift, which causes the rotor to rotate.

The rotation triggers a gearbox and generator to produce electricity.

Their uniqueness lies in their ability to generate clean, sustainable power without emitting greenhouse gases or relying on finite resources like fossil fuels.

Ideal inspection involves drones equipped with AI and laser tech capturing high-resolution images of turbine blades and nacelles.

Wind turbine inspection is crucial to identify defects early, ensuring operational efficiency and preventing potential catastrophic failures.

Lack of inspection can lead to undetected damages, compromising turbine functionality and safety.

Without inspections, defects like blade cracks or structural issues could escalate, resulting in costly repairs or even turbine failure.

Special Features of Wind Turbines

The special features of wind turbines include:

1. Vertical Axis Rotation:

Unlike traditional propeller-style turbines, modern designs have a vertical axis of rotation for more efficient energy capture across different wind directions.

2. Three Blades:

Using three blades allows for smoother airflow and improved efficiency during low wind conditions.

3. Hub Height Adjustment:

Increasing hub height (the distance between ground level and the rotor) maximizes exposure to higher-altitude wind currents.

Inspection Procedures Performed on Wind Turbines

There are different levels of inspection that can be performed on Wind Turbines, which include:

1. Surface Inspection:

This method involves examining the external components like blades and nacelles for visible damage or wear.

High-resolution cameras are mounted on drones or handheld devices to facilitate close-up visual inspections.

Crucial for detecting surface-level defects and assessing the overall condition of the turbine's exterior.

2. Sub-Surface Inspection:

Utilises technologies like thermal imaging or acoustic sensors to detect anomalies beneath the surface.

Thermal cameras or sensors can identify variations in heat or sound that indicate potential issues.

Helps detect hidden defects or structural abnormalities not visible to the naked eye.

3. Internal Inspection of Wind Turbines:

Involves accessing the internal components like the gearbox or generator for inspection.

Specialised inspection tools and equipment such as borescopes or robotic systems are used.

Allows for a detailed assessment of critical internal components for maintenance or repairs.

The different techniques that are available for inspection

1. Visual Assessment:

To examine the entire structure, including the tower, blades, hub, and foundation, looking for signs of damage or wear.

Sensors & Monitoring Systems: These are used to check the functioning of sensors monitoring temperature, vibration, noise, and other parameters to detect any abnormalities early on.

2. Aerodynamic Analysis:

This uses data collected from anemometers and wind tunnels to evaluate performance and identify areas for improvement.

3. Rope Inspection:

Here, technicians use ropes and harnesses to manually inspect turbine components.

Basic inspection tools and safety gear are employed during the ascent.

This is a traditional method for surface inspection but can be time-consuming and risky.

4. High-Resolution Cameras:

Cameras with high zoom capabilities are used to capture detailed images of turbine surfaces.

Drones or mounted cameras are used for close-up visual assessments.

This provides clear visuals for surface-level inspections, aiding in defect identification.

5. Manual Drone Inspection:

Drones equipped with cameras or sensors are manually flown around the turbine.

Remote-controlled drones with visual or sensor technology are used for inspections.

This offers flexibility in accessing different parts of the turbine for inspection.

Each method serves a specific purpose in wind turbine inspections, addressing different aspects of surface, sub-surface, and internal evaluations to ensure the turbine's proper functioning and maintenance.

Importance of Inspecting Wind Turbines

Inspection of wind turbines is imperative because of the following reasons:

1. Ensuring Efficient Energy Production:

Regular inspections maintain optimal performance and avoid unexpected downtime resulting in lost revenue.

Safety Considerations: Identifying defects or weaknesses in the structure helps prevent accidents caused by structural failure or malfunctioning components.

2. Compliance with Standards:

Periodic assessments ensure adherence to regulatory requirements and help maintain certifications necessary for operating a wind farm.

3. Frequency of Wind Turbine Inspection:

Wind turbines are often inspected annually, but the frequency can vary based on factors like manufacturer recommendations, environmental conditions, turbine age, and regulatory requirements.

A manual wind turbine inspection takes a full day, skilled technicians, and a lot of downtime.

AI-based drones are changing the game and reducing inspection time and risk, while producing more detailed data-based reports. 

Nearthlab is a Seoul-based company that uses drones equipped with artificial intelligence and laser technologies to help pinpoint potential damage to wind turbine blades and nacelle and reduce the chance of accidents during human inspections.

Autonomous drones are programmed to navigate wind towers using artificial intelligence (AI).

At the top of the tower, they take more than a thousand photos of the turbine's blades and nacelle—housing for the gearbox and brakes—to scan for potential defects and estimate the size and depth of cracks.

Using AI, the company analyses photographs to identify damage.

The drones work quickly:

they take 15 minutes to inspect a tower, compared with the day it takes a human technician to do the same using ropes and a harness.

The towers have to be idled for the duration of the inspection, so the faster, the better. 

This technology is expected to be especially useful as offshore windfarms continue to grow, eliminating the need for human technicians to conduct dangerous routine and spot inspections.

Other projects are working to go beyond inspection to use drones for repair and maintenance.

A recent study found that wind farms designed for maintenance by robots only will be possible by 2050.

The MIMRee (Multi-Platform Inspection, Maintenance, and Repair in Extreme Environments) project was funded by Innovate UK and led by OREC (Offshore Renewable Energy Catapult).

“Today, conditions at sea make human-only missions subject to safety risks, delays, cancellations, and extensive turbine downtime.

This will not be a feasible way of running the super-sized offshore power stations of tomorrow that lie in deep waters hundreds of miles from shore,” said Ben George of OREC.

For the MIMRee project, an autonomous mothership robot, produced by robotics pioneer Thales, uses an onboard inspection system to find defects in wind turbine blades. The inspection system can even scan turbine blades while they’re still spinning.

Once a defect is found, the mothership sends signals to the turbine to stop spinning and launches a specially adapted drone to the problem turbine. This drone carries a six-legged “blade crawler” robot that latches onto the blade and carries out the repair. UK start-up, BladeBUG, supplied the blade crawler robot to the project. The project developed this robot to be more effective at repairing blades and trained it using an advanced simulation.

“Increasingly, we are seeing the technologies around robotics, autonomy sensing, and AI providing solutions enabling activities involving harsh environments to be undertaken using unmanned systems,” said Dr. Paul Gosling, chief technical officer for Thales.

The Obligatory Job Discussion

As often happens when drones are brought in to do a task previously completed by a human, the industry wants to know the impact on jobs. 

Wind turbine service technicians being the fastest-growing job category in the U.S. The Bureau of Labor Statistics expects employment to grow about 60% over the decade that began in 2019.

While it might seem as though automated drones would put a damper on that growth, Bjorn Hedges, plant manager for two Washington State wind farms inspected by Nearthlab, said he isn’t too worried about the technology becoming a threat.

“With more wind turbines being built, the workload is increasing,” says Hedges, who works for NAES Corp. “There’s going to be little shortage of jobs.” The facilities’ technicians are now free to focus on performing tasks the drones can’t. 

These technologies clearly have the wind at their backs.

The Difference between Traditional and Modern Inspection Methods

1. Traditional Inspection Methods:

Relies on manual Visual Inspections conducted by technicians.

Often involves the operators climbing using ropes and harnesses.

A time-consuming process, taking up to a full day per turbine.

Limited NDT Inspection coverage due to human access constraints.

Higher safety risks for technicians working at heights.

2. Modern Inspection Methods:

Utilizes advanced NDT Technologies like AI-driven drones for inspections.

Enables high-resolution imaging and data collection.

Swift and efficient, reducing inspection time to minutes per turbine.

Comprehensive coverage of turbine components using autonomous drones.

Minimizes safety risks by eliminating the need for human ascent.

Vital Features of Autonomous Wind Turbine Inspections

The features of autonomous wind turbine inspections include the following:

1. ‘Click of a button’ operations:

This method Initiates automated Drone Inspections with ease and precision.

Enables quick and effortless deployment of inspection routines.

2. Asset Mapping:

In this technique, detailed maps and visual data of turbine components are generated.

This provides a comprehensive overview of the turbine's condition and potential issues.

3. Time Savings:

The inspection time is significantly reduced compared to manual methods.

It enhances operational efficiency by minimizing turbine downtime.

4. Reduced Risk:

Wind turbine inspection mitigates safety hazards associated with human-led inspections at heights.

It ensures safer working conditions for maintenance and inspection tasks.

5. Actionable Insights:

This method utilizes AI-driven analysis to provide detailed reports on turbine conditions.

It offers actionable information for maintenance and repairs, based on collected data.

Potential Issues Without Proper Maintenance

There are a number of obstructions that a process may face if proper maintenance and inspection aren’t carried out.

Some of them include:

1. Reduced Power Output:

Neglected turbines may experience decreased energy production due to worn parts, damaged blades, or obstructive debris.

2. Structural Damage:

Ignoring visual cues or sensor readings can lead to the catastrophic collapse of critical components like the blade root or tower foundation.

3. Fire Hazards:

Overheating or sparking due to faulty wiring or bearing failures can cause significant damage and put people nearby at risk.

4. Noise Pollution:

Malfunctioning turbines can emit excessive sound levels beyond acceptable limits set by environmental regulations.

Final Words

Autonomous drone inspections are revolutionizing the health and efficiency of wind turbines across industries.

By integrating Non-destructive Testing (NDT) techniques, these drones offer a comprehensive assessment of turbine components, ensuring optimal functionality and longevity.

These cutting-edge inspections utilize advanced AI-driven drones equipped with high-resolution cameras and NDT Technologies tailored for wind turbines.

They surpass traditional manual inspections, covering vast areas in a fraction of the time while providing intricate details of the turbine's health.

The impact of autonomous drone inspections extends beyond the renewable energy sector, benefiting various industries reliant on wind turbines.

Precision-driven assessments facilitate early detection of defects, structural anomalies, or wear, averting potential failures and costly repairs.

Additionally, these inspections contribute to enhanced safety measures by minimizing human exposure to risks associated with manual inspections conducted at heights.

By harnessing the power of autonomous drone technology, industries can ensure proactive maintenance, thereby maximizing the operational efficiency and lifespan of their wind turbines. 

Key Takeaways

Autonomous drone inspections revolutionize wind turbine health, integrating NDT for comprehensive assessments.

These NDT Inspections surpass manual methods, utilizing AI-driven drones to cover vast areas swiftly with detailed analyses.

They benefit various industries reliant on wind turbines, ensuring early defect detection and enhanced safety measures.

FAQs

1. How much is a wind turbine drone inspection?

A: The cost of a wind turbine Drone Inspection can vary based on factors such as the size of the turbine, the extent of inspection required, and the technology used. However, generally, drone inspections offer cost-effectiveness compared to traditional NDT Methods due to reduced downtime and increased efficiency.


2. How do you evaluate a wind turbine? 

A: Wind turbine evaluations involve various assessments, including Visual Inspections of external and internal components, data analysis from sensors monitoring temperature, vibration, and other parameters, as well as comprehensive checks for structural integrity and performance efficiency.


3. What 3 main factors determine the efficiency of a wind turbine? 

A: The three main factors determining wind turbine efficiency are the wind speed at the turbine's location, the rotor size (blade length), and the turbine's height above the ground.

These factors collectively impact the amount of energy a turbine can harness from the wind.


4. What is wind turbine reliability? 

A: Wind turbine reliability refers to the turbine's ability to operate continuously and consistently over a specified period without breakdowns or failures.

It encompasses the turbine's durability, performance, and ability to function optimally under various conditions.


5. What is the formula for MTBF of a wind turbine? 

A: The Mean Time Between Failures (MTBF) of a wind turbine is calculated using the formula: MTBF = Total Operating Time / Number of Failures.

This formula determines the average time interval between successive failures of the turbine, indicating its reliability and performance.



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