How is a Wind Turbine Tower refurbished?
The tower is the largest and heaviest element of a wind turbine. The transport and assembly of the tower accounts for a large proportion of the costs, in economic terms, about 15 to 25 % of the total costs of a wind turbine.
Wind turbine towers are subject to extreme stresses and environmental influences: wind, sun, salty air, frost and even waves and up to ten million load-strain cycles. And these environmental influences and dynamic loads can cause damage to the tower and/or to the connection between the tower and the foundation.
Most wind turbine towers are made of steel. They are welded together from a number of segments each of which can be 20 to 30 meters long. Corrosion most often occurs at the welding seams. Routine inspections can identify and repair such damage at an early stage to avoid later, more serious damage. When wind turbines are refurbished:
- Any existing corrosion on the tower, the weld seams and fundament anchors is thoroughly removed
- Corrosion protection is applied
- Flanged connections are sealed with a flexible sealing strip
Normally, tower refurbishing involves the application of a paint corrosion protection coating. However, instead of paint, corrosion protection film can also be used to protect the tower against corrosion. Compared to painted coatings, films offer numerous advantages. Apart from a longer service life and greater environmental friendliness, films are quick to apply and there are no drying times to be considered.