How Pitch Bearing Monitoring Is Transforming Wind Farm Maintenance

Wind power generation is one of the pillars of the global energy transition. Estimates from the International Energy Agency (IEA) point to an annual increase of over 100 GW until 2030. With the growth of new wind farms and the maintenance of existing ones, the challenges related to the operation and maintenance (O&M) of wind turbines are gaining even more prominence.This is because the main objective of the O&M sector is to maximize the availability and efficiency of wind turbines while minimizing failures and operational costs.Regarding failures and operational costs, one of the most critical and sensitive components of these systems are the pitch bearings, which connect the blades to the turbine hub and enable pitch control.

These bearings are subjected to high mechanical loads and severe environmental variations, such as salinity, dust, water, etc. When they fail, they can cause severe shutdowns, high replacement costs, and risks to the structural integrity of the turbine.With this in mind, AQTech developed an innovative solution: the application of a Condition Monitoring System (CMS) for pitch bearings, installed in the hub of the wind turbine.

The Challenge of Traditional Maintenance

Traditionally, the inspection of these bearings is carried out manually, with periodic inspections by the maintenance team inside the turbine hubs. Although widely used, this approach presents several limitations:

• Inspections provide only a “snapshot” of the blade clearances at the time of analysis and can only be carried out with the turbine shut down;

• The frequency of inspections tends to increase for turbines with recurring problems, requiring more manual activities by specialized labor;

• Failures are not always detected in time. Often, the bearings already show damage by the time of inspection, requiring corrective actions;

• Corrective actions require long downtimes, lasting from months to years;

• Operational costs grow significantly.

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It was this scenario that motivated the comparative study conducted by AQTech.

Case Study: 200 Turbines in Northeast Brazil

The study focused on a wind farm with 200 turbines installed in Northeast Brazil. Two scenarios were compared:

• Scenario 1: Semiannual manual inspections of all turbines, with additional monthly inspections on units where faults were detected.

• Scenario 2: Permanent CMS installation on all turbines, eliminating manual inspections.

Main Results

➤ Scenario 1 – Manual InspectionIn this scenario, the combination of semiannual inspections and monthly corrective actions for turbines with detected failures led to an accumulated downtime of 120 days per year for turbines requiring corrective actions.The total annual cost for bearing replacements reached €1,352,443.20.

➤ Scenario 2 – Permanent CMSThe adoption of CMS, despite requiring a higher initial investment, brought significant advantages:

• Reduction of downtime to 60 days per year. Greater predictability and real-time monitoring of failures, enabling better planning for preventive and corrective actions;

• Reduction of annual replacement costs to €579,312.00;

• Investment payback already achieved in the second year;

• Accumulated savings over 10 years with a 50% reduction in costs due to unplanned downtimes.

Furthermore, the CMS provides continuous data on bearing health, enabling more precise maintenance planning and avoiding unexpected failures.

Qualitative Benefits for O&M Teams

• Greater predictability and planning of interventions;

• Elimination of risky inspections at height;

• Data-driven and continuous decision-making;

• Optimization of resources and spare parts inventory;

• Cost reduction and better predictability for the Supply Chain sector.

Conclusion

The implementation of CMS for pitch bearings represents a significant advancement in the predictive maintenance of wind turbines. It reduces downtime, avoids unnecessary costs, and improves operational safety.AQTech’s solution has proven to be strategic in increasing the reliability and profitability of wind farms.

With this case study, AQTech reaffirms its commitment to technological innovation applied to the energy sector, strengthening Brazil’s role as a protagonist in the transition to a cleaner and smarter energy matrix.