Why Offshore Wind Maintenance Is Risky - and How Smarter Tech Can Help

As global demand for clean energy surges, offshore wind power has emerged as a pivotal force in the transition to renewable energy. According to international forecasts, offshore wind capacity is expected to grow exponentially over the next two decades, particularly in Europe, Asia, and the United States. Taiwan, as a key player in Asia's offshore wind sector, has been actively pushing forward its first and second phase offshore wind farm projects, aiming to meet long-term net-zero goals.

The inherent difficulty of servicing turbines located miles offshore in harsh marine environments creates numerous operational hurdles. Maintenance crews contend with unpredictable weather, rough seas, and limited access windows, all of which increase the risk of accidents and delays. Traditional maintenance methods—relying heavily on manual inspections, diving operations, and crewed vessels—are not only labor-intensive but also constrained by safety regulations and environmental factors. These limitations lead to extended downtime, higher operational expenses, and can ultimately impact the reliability and energy output of wind farms.

This article delves into why offshore wind maintenance remains a persistent challenge despite the sector’s rapid growth. It also highlights how emerging smart technologies—such as remotely operated vehicles (ROVs), artificial intelligence (AI), and real-time monitoring systems—are beginning to transform maintenance practices. By enhancing operational safety, improving efficiency, and reducing costs, these innovations offer promising solutions to optimize maintenance workflows and support the sustainable expansion of offshore wind energy worldwide.

The Offshore Wind Farm Lifecycle: Construction, Maintenance, and Decommissioning

An offshore wind farm has three key lifecycle phases: Construction, Operation & Maintenance (O&M), and Decommissioning. Each phase relies on inspecting and servicing underwater infrastructure, but the O&M phase is the most time-consuming, hazardous, and costly.

1. Construction Phase: Laying the Foundation

Construction begins with geological surveys and environmental assessments, followed by installation of turbine foundations (e.g., monopiles or jackets), subsea cable laying, and turbine assembly. This phase involves heavy engineering vessels, cranes, and professional dive teams, with real-time monitoring via sonar and underwater imaging systems to ensure stability and accuracy.

2. Operation & Maintenance Phase: The Longest and Riskiest Stage

Once operational, offshore wind farms enter a 20–25 year O&M phase. Key maintenance tasks include:

• Monitoring subsea cables and trenches
• Inspecting turbine foundations for corrosion and cracks
• Observing and preventing seabed scour
• Servicing nacelles and blades
• Biofouling removal and anti-corrosion treatments

These tasks often involve manned vessels equipped with underwater instruments for inspection and data collection. While some operators are transitioning to smart technologies like remotely operated vehicles (ROVs), but some maintenance operations remain dependent on human labor and diver-based methods. Limited weather windows further constrain scheduling, driving up labor costs and increasing turbine downtime—ultimately impacting overall energy output. 

3. Decommissioning Phase: Safe Removal and Environmental Restoration

When turbines reach end-of-life or are retired for economic reasons, the decommissioning phase begins. This involves dismantling turbines and foundations, recovering subsea cables and electrical systems, and restoring seabed conditions. While shorter than other phases, this stage still requires thorough structural evaluations and pollution risk management.

Why Offshore Wind Maintenance Operations Are Especially Hazardous

Offshore wind maintenance faces higher technical barriers and safety risks compared to onshore operations. Complex logistics, severe environments, and tight scheduling windows contribute to these dangers.

1. Harsh Sea Conditions and Weather Constraints

Most offshore wind farms are located more than 20 km from shore, facing strong winds, currents, and waves year-round. Limited weather windows—an average of only 120–150 suitable days annually, mostly in summer—tighten scheduling and delay repairs.

2. High-risk Transport of Personnel and Equipment

Technicians and equipment must be transported via Crew Transfer Vessels (CTVs) or Offshore Support Vessels (OSV), with personnel transferring using walk-to-work systems or cranes. In wave heights above 1.5 meters, transfers become dangerous, risking falls, collisions, or injuries. Improperly secured equipment may corrode or sustain damage in transit, reducing repair effectiveness.

3. Limited Diving Capabilities and Safety Hazards

Despite technology, many underwater tasks still require divers. But at depths over 30 meters, dive time drops below 20 minutes, and decompression procedures are required. Divers face fatigue, hypothermia, and decompression sickness, especially in low visibility and turbulent currents near turbine foundations.

4. High Costs and Elevated Risks

Offshore maintenance costs are roughly double those of onshore due to insurance, training, vessel deployment, and safety gear. Unexpected faults—like blade damage or foundation cracks—require emergency response teams, driving up costs and downtime, and severely impacting revenue.

The Limits of Traditional Maintenance Methods

Despite the rapid expansion of offshore wind capacity worldwide, many operators continue to rely on outdated maintenance models that prioritize reactive responses and labor-intensive inspections. 

While this approach may reduce short-term maintenance expenditures, it often results in unplanned turbine shutdowns, costly emergency vessel mobilizations, and disruptions to the broader maintenance schedule. The unpredictability of such failures forces operators to respond on short notice, often under suboptimal weather conditions, which not only increases risk but also prolongs downtime. 

This, in turn, leads to revenue losses and higher cumulative repair costs. Given that operation and maintenance can account for 15 to 25 percent of a wind farm’s total lifecycle cost, relying on reactive strategies poses a substantial financial burden.

While there is a global trend shifting towards the use of ROVs for subsea inspection, a small number of sites still use human divers for simple visual assessments of turbine foundations, subsea cables, and scour protection systems. These human-led methods introduce avoidable risks and inefficiencies are in need of change. 

Dive operations are constrained by weather, depth, and time limits, while poor underwater visibility and strong currents can reduce the accuracy of data collected. The process is slow, often requiring multiple trips to collect adequate footage, analyze results, and plan remedial actions. Moreover, diver safety remains a concern, adding a layer of liability and complexity to routine inspections.

Even in wind farms equipped with sensors and digital monitoring tools, fragmented data management remains a significant obstacle. Many systems operate in silos, with performance and condition data distributed across separate platforms or subsystems. This lack of integration makes it difficult to identify patterns or detect early signs of equipment degradation. Without centralized analytics or real-time diagnostic tools, operators face delays in diagnosing faults, prioritizing interventions, and coordinating responses. As offshore wind farms scale up in size and technical complexity, these delays can result in greater operational inefficiencies and missed opportunities for cost savings.

To remain competitive and sustainable, the offshore wind industry must evolve beyond traditional maintenance models. This means embracing more integrated, data-driven approaches that reduce reliance on manual inspections and improve responsiveness to emerging issues. Transitioning away from reactive strategies is not just a matter of improving uptime—it is essential for optimizing long-term asset performance and ensuring the economic viability of offshore wind at scale.

Managing Offshore Wind Operation and Maintenance Costs Through Proactive Strategies

Offshore wind energy has emerged as a key player in the global transition to clean energy. With the potential to generate large-scale renewable power, offshore wind farms are becoming increasingly popular among governments and energy companies alike. However, while these projects bring long-term environmental and economic benefits, they also come with high upfront costs and complex operational demands. One of the biggest challenges in ensuring long-term profitability lies in controlling operation and maintenance (O&M) expenses. 

According to data from Weather Guard Wind, the average commercial wind turbine costs between US$2.6 million and US$4 million to install. While this figure is substantial, it’s only part of the total cost of ownership. Operation and maintenance alone can account for 15% to 25% of a wind farm’s total lifecycle costs. This makes efficient O&M strategies critical—not only for maximizing turbine performance but also for protecting return on investment.

Routine maintenance of above-water turbine components—like blades, nacelles, and towers—is relatively well-established. These parts are often monitored through sensors that track temperature, vibration, oil condition, and other performance indicators. When issues arise, they are typically addressed through scheduled inspections and planned interventions, usually during optimal weather conditions. This helps minimize disruptions and reduces the need for costly emergency repairs.

However, the real complexity begins below the waterline. Subsea foundations, inter-array cables, and scour protection systems are constantly exposed to aggressive marine conditions including strong currents, saltwater corrosion, and biofouling. These factors accelerate wear and make underwater inspections and repairs particularly challenging. Accessing these assets requires specialized vessels and equipment such as divers or remotely operated vehicles (ROVs), along with highly trained personnel. The underwater environment limits visibility and complicates diagnostics, often extending repair times and increasing costs. Additionally, subsea failures can have cascading effects on the entire wind farm’s stability and power transmission, making timely detection and intervention crucial.

Maintenance for offshore wind farms, especially subsea infrastructure, has often been reactive—triggering costly, risky emergency mobilizations in difficult weather. These unplanned repairs result in longer downtimes and lost energy production. In contrast, a proactive approach uses real-time sensor monitoring and predictive analytics to detect early signs of wear on above-water turbines before issues escalate. Below the surface, operators increasingly rely on remotely operated vehicles (ROVs) for regular, detailed inspections, enabling faster and safer identification of potential problems. 

This shift from reactive to proactive maintenance helps reduce downtime, lower costs, and improve overall reliability. By combining data-driven insights with advanced technologies like ROVs, operators can better plan maintenance activities, reduce dependence on emergency interventions, and ultimately extend the lifespan of both surface and subsea infrastructure. This approach not only lowers lifetime O&M costs but also improves the reliability and energy availability of offshore wind farms.

Smart Tech is Transforming Offshore Wind Maintenance

The offshore wind industry is undergoing a digital transformation. New technologies are enabling faster, safer, and more cost-effective maintenance. Key innovations include:

1. Remotely Operated Vehicles (ROVs): Reducing Diver Reliance

ROVs are underwater robots controlled from the surface, capable of carrying out inspections, measurements, and minor repairs. They provide high-definition video, sonar mapping, and real-time feedback without the need for human divers. Advanced ROVs can operate at greater depths and in more hazardous conditions than human crews, drastically reducing risk.

In Taiwan, companies like DWTEK are pioneering ROVs adapted to local waters. These models are designed for wind farms and feature interchangeable modules, simplifying maintenance workflows.

2. Autonomous Underwater Vehicles (AUVs) and Drones: Efficient Data Collection

AUVs operate without tethering, using pre-programmed routes to collect subsea data, such as scour patterns or cable positions. Drones can inspect turbine blades and nacelles without climbing equipment or scaffolding. Together, they enable faster data collection, reduce technician exposure, and support frequent condition assessments.

3. Real-Time Monitoring Systems and IoT Integration

Sensors embedded in turbines, foundations, and cables continuously collect data on vibration, temperature, corrosion, and fatigue. These IoT-connected systems stream data to centralized platforms for remote monitoring, fault detection, and trend analysis.

Operators can detect anomalies early, schedule repairs proactively, and allocate resources more efficiently. This minimizes downtime and improves turbine uptime.

4. AI and Machine Learning: Smarter Decision Making

AI models trained on historical and real-time data can forecast equipment failures, identify inefficiencies, and optimize scheduling. For example:

• Anomaly detection algorithms can spot subtle signs of corrosion or fatigue.
• Predictive analytics can recommend optimal inspection intervals.
• Machine learning improves over time, reducing false alarms and maintenance redundancies.

Together, these technologies enable a shift from reactive to predictive maintenance, boosting safety and profitability.

How ROVs Make Subsea Maintenance Safer - DWTEK in Action

Offshore wind farms are a vital pillar in the global transition to clean energy. However, the complexities of subsea maintenance continue to pose significant challenges. Traditional inspection methods, which rely heavily on human divers, are constrained by limited operational depth, restricted mobility, and considerable safety risks in unpredictable underwater conditions. As offshore infrastructure grows in both scale and technical sophistication, these limitations become even more pronounced—highlighting the urgent need for safer, faster, and more reliable inspection solutions.

In response, offshore wind operators are increasingly adopting advanced technologies to enhance maintenance efficiency and reduce risk—particularly in demanding subsea environments. Among these innovations, Remotely Operated Vehicles (ROVs) have emerged as a transformative answer to these challenges. These unmanned systems eliminate the need for human intervention in hazardous environments and enable real-time diagnostics with enhanced precision. Equipped with integrated sonar, high-definition cameras, and LED lighting, ROVs can inspect monopile foundations, subsea cables, and scour protection structures regardless of water visibility or sea state. 

DWTEK, Taiwan’s first homegrown ROV manufacturer, has become a driving force behind the offshore wind transformation. DWTEK’s modular ROV systems are designed specifically for marine conditions and can be quickly adapted with tools such as Pan & Tilt, ROV cameras, ROV lights, and cleaning arms etc. This level of flexibility ensures that mission requirements—whether structural inspection, environmental monitoring, or post-storm assessment—are met with efficiency and accuracy.

In addition to its ROV systems, DWTEK also provides the personnel and operational expertise needed to carry out offshore maintenance inspections—including experienced ROV pilots, technicians, and project operators. This all-in-one service model is especially valuable in offshore wind, where operators frequently face limitations in vessel access and lack in-house ROV operation capabilities. DWTEK closes this gap by offering a complete package: ROV equipment, crew, and operational support.

One recent example highlights the impact of this approach. DWTEK Pilots deployed customized ROV systems to an offshore wind farm in Asia to carry out a range of tasks, including monopile inspections, cable trench evaluations, and post-typhoon asset condition assessments. The project was completed in half the scheduled time with zero diver exposure. 

High-quality visual and sonar data were made available to remote stakeholders, enabling rapid planning for follow-up maintenance. The result was a significant improvement in both safety and operational readiness.

Through continuous innovation and extensive real-world deployment, DWTEK is redefining the standards of offshore wind maintenance. Its ROV systems go beyond advanced inspection technologies; they act as critical strategic assets that significantly enhance safety, accuracy, and operational efficiency. By enabling operators to move away from hazardous, diver-dependent inspections toward intelligent, data-driven maintenance frameworks, DWTEK is pioneering a safer, more dependable, and environmentally sustainable approach to subsea wind farm upkeep.

Final Thoughts: Safer Maintenance Is the Future of Offshore Wind

Offshore wind is a cornerstone of the global energy transition, but its long-term success hinges on overcoming the challenges of operations and maintenance (O&M). Harsh marine environments, limited personnel access, and high-risk conditions make every repair a costly and complex task. Whether it's underwater structural inspections or emergency turbine fixes, any delay or oversight can lead to unplanned downtime, rising costs, and even safety hazards. That’s why building a safer, more stable, and predictive maintenance strategy is critical for sustainable offshore wind operations.

Fortunately, with technological advancements, intelligent O&M solutions are no longer theoretical—they’re available today. Tools like AI-driven analytics, automated monitoring sensors, digital wind farm platforms, and advanced ROVs (remotely operated vehicles) are transforming how we manage offshore wind infrastructure. Specifically, ROVs equipped with sonar and imaging systems are replacing risky manual underwater inspections, setting a new standard for unmanned, high-efficiency, real-time maintenance.

Predictive maintenance is also revolutionizing the field. By collecting and analyzing long-term operational data, these systems can forecast equipment wear, detect anomalies early, and recommend scheduled maintenance—well before failure occurs. This not only improves turbine uptime and performance but also reduces the number of costly, last-minute repairs. Most importantly, it minimizes the need to send workers into offshore conditions, enhancing both safety and efficiency.

As Taiwan’s leading developer of underwater technologies, DWTEK is committed to helping operators meet these challenges with smart, localized solutions. We design and build ROV systems, integrated inspection tools, and real-time data platforms that meet the specific needs of the marine environment. Our focus is on reducing risk, increasing efficiency, and ensuring front-line worker safety throughout the O&M cycle. Explore DWTEK’s full ROV range or contact us to get more information.