After ten to twenty years of operation, wind turbines often reach the point where central components reach their wear limits. Large components such as gearboxes, main bearings, generators or rotor blades are particularly affected. Replacing them poses technical, logistical and economic challenges for operators – but at the same time offers the opportunity to significantly extend the service life and cost-effectiveness of existing systems.
The following article explains which components are typically affected, how a large component replacement works, what risks and planning requirements exist – and why this measure is increasingly becoming a key factor for the safe and sustainable continued operation of wind turbines.
1. Introduction
Wind turbines are subject to a technical
Lifespan of about 20 to 25 years. But like any complex
technical system, they are subject to natural wear and tear. Particularly strong
the large, central assemblies – the so-called
Large components. If they fail or show clear signs of
material fatigue, operators have an important role to play in
Decision before: Repair, replace or shut down the plant?
Replacing large components is usually time-consuming, expensive and logistical
demanding. At the same time, it can increase the service life of a wind turbine by
many years and the availability is restored to a high level
bring. For many operators, the exchange is therefore a key issue in continued operation
and lifetime management of their systems.
This guide explains in a practical way when a large component replacement
which components are affected, what the process looks like,
what challenges can arise and when such an intervention
Worth.
2. What does "large component replacement" mean?
A large component replacement is understood to mean
replacement of one or more central mechanical or electrical
Main assemblies of a wind turbine. These components are large, heavy,
expensive and often only with special cranes, transport vehicles and specialist personnel.
handle.
Typically, large component replacements are not routine maintenance, but part of the
major maintenance measures, which are usually carried out after a defect, severe
wear or in the context of service life extensions.
The goal of a large component replacement is to:
- ensure the operational readiness of the plant,
- extend the service life,
- and consequential damage caused by continued operation with defective or
worn parts.
3. Which components are affected?
The following components are considered to be
classic "large components", the replacement of which typically requires the largest
effort and the highest costs:
Blades: They are among the largest and most expensive components. Damages
are caused by cracks, lightning strikes or erosion.
Main bearing: Carries the entire rotor mass. Typical damages: Pitting,
Wear, vibrations.
Transmission: Gear – prone to tooth chips, bearing damage,
Oil contamination.
Generator: Converts mechanical energy into electrical energy – often affected
due to overheating and insulation damage.
Rotor shaft: Transmits rotational motion, highly stressed by torsion.
Transformer / power electronics: damage caused by thermal stress or
Overvoltage.
Gondola frame and hub: Rare exchange, but relevant for structural
Damages.
4. Typical causes and damage patterns
Large component damage rarely occurs
sudden. Common causes:
- Material fatigue due to load changes and turbulence
- Wear and Lubricant Aging
- Vibrations and imbalances
- Temperature changes
- Corrosion and moisture
- Thunderbolt
- Improper maintenance
Signs are vibration, temperature rise, oil particles in the transmission oil or
conspicuous noises. Condition monitoring systems (CMS) help to prevent damage
at an early stage.
5. Challenges of large component replacement
A large component replacement is technically
complex. Challenges include:
- Logistics: Transport of parts weighing up to 60 tonnes
- Crane work: expensive, weather-dependent, sensitive to wind
- Accessibility: Paths must be sustainable
- Spare parts availability for older systems
- Coordination of many trades
- Security requirements and insurance issues
6. Procedure for a large component replacement
Typical course of events in six phases:
- Diagnosis and planning: damage analysis, spare parts procurement, scheduling.
- Preparation: Shutdown, fuse, construction site equipment.
- Dismantling: Removal of the defective component with cranes.
- Transport: Removal and delivery.
- Installation: Assembly and calibration.
- Commissioning: Functional test, documentation, acceptance.
Advantages of a professional large component replacement
A professional exchange offers:
- Service life extension by 5-10 years
- Restoration of availability
- Cost control through planned measures
- Sustainability through refurbished components
- Technical optimizations through newer assemblies
8. For which systems is the large component replacement
meaningful?
A large component replacement is usually worthwhile
for investments between 10 and 20 years with good substance and economic
Operation. Ideal for continued operation option or secondary market sale.
9. Manufacturers and plant types – practical examples
Enercon: gearless, exchange of
Generator bearings, pitch systems, rotor blades. (Enercon E40, Enercon E44, Enercon E48, Enercon E58, Enercon E66, Enercon E70, Enercon E82)
Vestas: frequent gearbox or main bearing changes (Vestas V52, Vestas V80, Vestas V90).
Siemens / Gamesa: modular design, typical gearbox exchanges,
Yaw systems.
Nordex: frequent bearing and gearbox replacements (Nordex N60, Nnordex N80, Nordex N117).
GE: Need for replacement of gearboxes (1.5 MW, 2.5 MW series).
10. Conclusion
The replacement of large components is a central
Part of the life cycle management of wind turbines. It extends the
service life, increases availability and contributes to the cost-effectiveness and
sustainability of existing wind farms.
