Engineering challenges in the maintenance of offshore wind farms

Mayuly Rodríguez.

November 24, 2023

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Author: Ing. Mayuly Rodríguez, November 24, 2023.

Introduction

Offshore wind farms are impressive structures and examples of advanced engineering and sustainability, which face challenges in their construction, operation and maintenance. It is an important source of renewable energy that represents an excellent energy alternative to achieve decarbonization objectives.

Its success depends on methodological planning and execution. In this context, maintenance management faces major problems, particularly due to the adverse conditions of the marine environment and the demand for advanced technologies for effective management. Furthermore, its success is also linked to specialized technical knowledge, given that it is a relatively new energy option in the field of clean energy.

In 2022, global offshore wind installed capacity reached 39.2 GW, an increase of 27.5% from the previous year. This trend is expected to continue in the coming years, due to the series of advantages that offshore wind farms offer over other renewable energy sources.

General challenges of offshore wind engineering

The global offshore wind energy industry is in constant development as it advances and is presented as a great opportunity for industrial economic development, being the European continent with the greatest progress. This industrial sector faces serious engineering problems, both currently and in the future:

Determine optimal locations that maximize energy production
Make development decisions based on detailed and strategic information
Streamline and facilitate development approval processes
Minimize investment uncertainty and risks
Ensure the robustness of the foundations against the aggression of waves and wind
Increase safety and efficiency in operations
Carry out maintenance that is effective and safe
Repower or dismantle projects efficiently and sustainably

Importance of maintenance on marine assets

Offshore wind farms are particularly subject to degradation due to salt-laden air, high wind speeds and continuous exposure to solar rays; In this sense, maintaining them is of utmost importance for the maritime industry. Effective maintenance management guarantees the safety of structures and personnel in adverse conditions, in the same way it improves operational efficiency, reduces downtime and maximizes production.

This discipline contributes to prolonging the useful life of offshore equipment and infrastructure, preventing costly failures and promoting environmental sustainability. Furthermore, it drives adaptation to new technologies and practices, effectively addressing current challenges in the marine environment.

Challenges and alternatives available in the maintenance of wind farms

During the operational period of an offshore wind farm, a series of scheduled and unscheduled maintenance tasks are performed to keep the turbines operating under reliable conditions, thus ensuring continuous power generation.

Keeping these systems in optimal conditions not only maximizes their efficiency, but also generates profitability for investors. These structures, located in the unforgiving marine environment, face problems; which must be resolved with the inclusion of accessible alternatives:

Access and logistics on the high seas: The transportation of personnel and equipment to offshore wind farms is a relevant challenge, they are expensive and logistically challenging, these are carried out using ships and helicopters. Remote locations, unpredictable weather patterns, and limited resource availability are obstacles to maintenance operations.

An effective solution: Integrated Wind Solutions subsidiaries have collaborated to develop an innovative operation and maintenance concept for foundations and offshore substations. Integrating IWS Fleet service vessels, IWS Services supply chain management and ProCon in-house maintenance skills into a single service package. With a suite of maintenance services that eliminates the need for multiple sub-suppliers and interfaces, they have hybrid vessels equipped with a novel gangway system for safe and easy access to the offshore foundation, and a team of specialized technicians with the skills necessary maintenance¹ .

Accessibility in adverse conditions: Access to offshore turbines, both in the aerial and submerged parts, is complex and dangerous, especially during bad weather, which makes any maintenance operation difficult, whether scheduled or unscheduled.

An innovative idea: A European project, ATLANTIS, uses robotics to perform remote inspections and maintenance in difficult conditions. The combination of intelligent software and robots increases the working hours of maintenance vessels by 35%, optimizing operations even in adverse weather conditions.

Another relevant alternative is the integration of remote maintenance operations through the use of robotics and autonomous systems, which today are effective options to minimize access to marine parks when conditions are unfavorable.

Security risks: These environments are complex and require strict security measures. The activities demand rigorous strategies because they involve working at high altitudes, confined spaces and underwater environments; which increases the risk of accidents and injuries. The protocols are strict to protect workers. The use of specialized technology and equipment is necessary to guarantee safety in all operations.

High costs: They are due to the technical and logistical complexity of working on the high seas, requiring strict security measures and specialized logistical resources. Additionally, challenges include increased risk of equipment failure. These factors, combined with the need for specialized training of personnel, contribute to increased maintenance costs.

A novel proposal: Emobi Industries, through its subsidiary Inbersa, has signed an agreement with Esteyco to manufacture the ATOMS prototype, an innovative project financed by the European Commission that seeks to transform the maintenance of offshore wind turbines. ATOMS involves the design of a steel platform that facilitates maintenance, eliminating the need for large vessels, reducing operating costs. This development is a step forward in the European Union’s decarbonization and energy transition efforts, and its success could mark a major shift in the offshore wind industry globally. It will begin manufacturing at the end of 2023, and will be awarded in Gran Canaria during the summer of 2024 and if successful, it will have a global commercial outlet ² .

Fault detection and repair: Due to the remote location and adverse conditions, accurate remote fault diagnosis is complicated. The size of the turbine, both its aerial and submerged parts, influences the response time in the event of maintenance. .

The use of digital twins creates virtual replicas of physical assets, facilitating real-time monitoring and predictive maintenance, improving decision making. This approach, aligned with Industry 4.0 standards, allows for more effective management of the life cycle of wind turbines.

The use of underwater drones makes maintenance more efficient and profitable. These remotely operated vehicles (ROVs) replace the costly and dangerous inspection process by divers, being able to perform inspections and maintenance more safely, equipped with cameras and sensors.

Using advanced data analytics and machine learning algorithms, operators can predict potential failures based on historical data and current operating conditions.

Complexity in repairs: Any offshore maintenance operation is called complex, and requires specialized equipment and personnel, and appropriate time to execute the activity efficiently.

Precise solutions: Rope Robotics, launches the first robot for wind turbine repairs, is the first to offer commercial repairs; It is four times faster than the manual method at half the cost, safety for technicians; test repairs are being carried out on marine turbines; Danish company will incorporate AI into its offshore wind turbine blade maintenance robot and is planning its commercial launch for 2024³ .

Implementation of digital technologies: Integrating digital strategies represents a significant challenge due to several factors. First, the integration of advanced systems such as data analytics and artificial intelligence requires a rigorous infrastructure resistant to marine conditions. Additionally, ensuring reliable and secure connectivity for continuous monitoring and predictive maintenance is complex.

Alternative solutions: Advances such as digitalization, artificial intelligence , and hybridization with storage systems have been incorporated. These technologies improve the operation of the parks and optimize maintenance.

The offshore wind energy maintenance market is developing varied and innovative proposals to overcome various challenges and become one of the most important in the naval industry. Collaboration between offshore wind farm operators, maintenance companies and equipment manufacturers is essential to drive development and solve common challenges.

Main types of maintenance in an offshore wind system

When offshore wind energy production operations and maintenance services are effectively optimized, the best long-term performance of these assets is achieved. Wind turbine operators use corrective, preventive and predictive maintenance to maintain operational continuity of their machines.

Corrective maintenance: These are repairs of breakdowns or execution of unscheduled emergency maintenance. Data analysis and control of the equipment involved in these maintenance is necessary to provide comprehensive services to offshore wind and identify possible incidents in real time. To minimize the impact of these corrective actions, a stock of spare parts and critical components must be maintained.

Predictive maintenance: These are strategies based on predictive actions such as oil analysis, vibration measurements and thermography to anticipate any malfunctions that develop slowly and minimize unforeseen breakdowns. In this maintenance, sensors are used to monitor the various elements of a turbine, including speed, temperature and vibration. Software programs analyze this data and recommend whether a turbine needs repair.

Preventive: Refers to all the actions that are scheduled in the maintenance manual of offshore wind turbines (periodic inspections, routine maintenance that is carried out once or twice a year, which can last up to one day per wind turbine), which are necessary to guarantee that operate in optimal conditions throughout their life cycle.

How does poor maintenance management affect an offshore wind farm?

This action has direct and significant impacts on the performance and availability of clean energy generation systems. The main effects are the following:

Decreased energy production: Inadequate maintenance or lack thereof causes failures in wind turbines, reducing energy production. In some cases, breakdowns can be so serious that they cause the turbine to be disconnected from the electrical grid.
Increased costs: Inefficient or outdated maintenance increases operating costs. These cause more frequent and severe breakdowns and failures, which in turn require urgent repairs or even the replacement of critical components. They cause prolonged downtime, increasing indirect costs.
Reduction in the useful life of turbines: Component wear is accelerated, structural fatigue is generated, and materials are degraded. This accelerated deterioration results in the premature need to replace key equipment, leading to a significant reduction in the expected life cycle of the turbines.
Major contributing factors include: Lack of planning and organization, lack of resources, inadequate maintenance equipment, and lack of staff training. To avoid the negative effects of poor management, it is important to establish an effective program that includes the following elements: A preventive plan that establishes a schedule of inspections and repairs, a qualified team and a rigorous maintenance management system, which allows monitoring of tasks and the identification of any adverse situation.

Conclusion

Offshore wind energy is a fundamental technology to drive the decarbonization of the global economy. Although maintenance experts face several tests, they continue to push the boundaries of innovation to overcome these challenges in offshore wind farms . With greater advancements in technology, environmental considerations and stakeholder engagement, the maintenance efficiency of these mega structures is addressing the best solutions to efficiently maintain operational continuity while ensuring safety.