Wind Turbine Service Inspections
Comprehensive scheduled maintenance performed according to OEM requirements and operator specifications. Annual, semi-annual and periodic inspections ensuring optimal turbine performance and regulatory compliance.
Maximising turbine availability through systematic inspections
Scheduled maintenance is the foundation of reliable wind turbine operation. Regular inspections allow early detection of wear and potential failures, minimising unplanned downtime and extending component service life.
We perform maintenance according to OEM schedules – annual, semi-annual and periodic inspections tailored to specific turbine models and operating conditions. Each inspection follows manufacturer-defined checklists while incorporating operator-specific requirements and local regulatory standards.
Maintenance cycles tailored to OEM requirements
Annual Service Inspection
The most comprehensive inspection type, covering all turbine systems and components. Performed once per year according to the OEM maintenance schedule.
Scope includes:
• Complete drivetrain inspection – gearbox, generator, main bearing
• Full electrical system review – all cabinets, connections, protection systems
• Hydraulic system – pumps, cylinders, accumulators, brake system
• Pitch and yaw systems – motors, gearboxes, bearings, encoders
• Safety systems – emergency stops, overspeed protection, sensors
• Tower and foundation – visual inspection, bolt torque checks
• Blade inspection – surface condition, leading edge, lightning protection
Duration: 2–3 days per turbine (team of 2 technicians)
Semi-Annual Service Inspection
Intermediate inspection focusing on critical systems and wear components. Performed 6 months after the annual inspection.
Scope includes:
• Drivetrain visual inspection and oil level check
• Electrical connections – thermal imaging, torque verification
• Hydraulic system – pressure checks, leak inspection
• Pitch system – greasing, functional test
• Yaw system – brake pad inspection, greasing
• Safety system functional tests
• Filter replacements as required
• CMS data review and trending analysis
Duration: 1–1.5 days per turbine (team of 2 technicians)
Periodic Inspections
Additional inspections scheduled according to operating hours, specific OEM service bulletins, or operator requirements.
Types include:
• Quarterly inspections – visual checks, greasing schedules
• Monthly inspections – basic operational checks
• Post-event inspections – after grid faults, extreme weather
• Service bulletin implementations – OEM-mandated checks
• Pre-warranty expiry inspections
• Condition-based inspections – triggered by CMS alerts
These inspections complement the standard annual/semi-annual cycle and address specific operational requirements or manufacturer recommendations.
Duration: Variable depending on scope
Systematic coverage of all turbine systems
• Gearbox – oil level, temperature, vibration, visual inspection
• Generator – bearing condition, cooling system, connections
• Main bearing – greasing, temperature monitoring
• Brake system – pad wear, disc condition, hydraulic function
• Yaw system – gearbox, motor, bearing, brake pads
• Pitch system – gearbox, motor, bearing, battery backup
• Couplings and shafts – alignment, wear indicators
• Control cabinets – connections, thermal imaging, dust removal
• Power cables – visual inspection, terminations
• Converter – cooling, capacitors, connections
• Transformer – oil level, temperature, connections
• Switchgear – contact condition, operation test
• Sensors and encoders – calibration verification
• Lightning protection – continuity, earth resistance
• Aviation lights – function test
• Emergency stop system – all E-stops functional test
• Overspeed protection – sensor calibration
• Vibration monitoring – sensor function, thresholds
• Fire detection – sensor test, alarm function
• Tower access – ladder, platforms, fall protection
• Rescue equipment – inspection, certification dates
• Safety signage – condition, visibility
• First aid equipment – inventory check
Structured approach to maintenance delivery
Each scheduled maintenance follows a structured procedure ensuring completeness, safety compliance and clear documentation:
1. Pre-service preparation
Review of previous service reports, CMS data analysis, preparation of required materials and spare parts, coordination with site operator
2. Site mobilisation
Safety briefing, LOTO procedures, work permit activation, equipment setup
3. Systematic inspection
Execution according to OEM checklist, component-by-component verification, measurements and functional tests
4. Servicing activities
Greasing, filter changes, torque checks, minor adjustments, consumable replacements
5. Documentation and handover
Complete service protocol, photo documentation, findings report, recommendations for follow-up actions
Complete records for compliance and planning
Every inspection is documented according to industry standards and operator requirements:
Service protocol
• Completed OEM checklist with all inspection points
• Pass/fail status for each component
• Measured values where applicable
• Technician signatures and timestamps
Findings report
• Identified issues ranked by severity
• Photographic evidence of wear or damage
• Recommended corrective actions
• Estimated timeframes for repairs
Operational recommendations
• Suggested monitoring parameters
• Optimisation opportunities
• Planning input for future maintenance
All documentation is delivered in digital format compatible with common CMMS systems.
Maintenance for turbines from leading OEMs
Certified team for comprehensive service delivery
All scheduled maintenance is performed by personnel holding:
• GWO Certifications
BST, BTT, ART – complete Global Wind Organisation training package required for wind turbine work
• Electrical Qualifications
Certified for work on LV, MV and HV installations according to local regulations
• Mechanical Qualifications
Certified for drivetrain and rotating equipment work
• OEM Training
Manufacturer-specific training including Vestas certified courses
• HSE Compliance
Full compliance with site-specific safety procedures and operator requirements
Ready to schedule your turbine maintenance?
Contact us to discuss your maintenance requirements. We offer flexible scheduling, competitive rates and reliable service delivery across Central and Western Europe.