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How Long Do Wind Turbines Last Before Needing to Be Replaced?

Governments use the expected output of wind turbines over the course of their lifetime to make predictions about where their energy will come from in the future. For this reason, it's important to have accurate estimates of turbines' longevity. Although turbines are intended to last for around 20 years, there is some evidence that their functional lifespan is much shorter than this.

Design Lifetime
- Wind turbines are designed to last for 20 years. Engineers design and build turbines with the aim that no part will fail in this time span. This is because some parts of the turbine are too expensive to build for a longer lifespan, and it is more economical to simply replace these parts. However, this design lifetime does not mean that turbines will break exactly 20 years after being put into operation and a report by the Intergovernmental Panel on Climate Change notes that 25 years is the most commonly suggested operational lifetime.
Economic Lifetime
- A study conducted at the University of Edinburgh analyzed data from 1,105 wind turbines in Denmark and the United Kingdom. The results suggested a drastic decline in output of around a 33 percent after 10 years of operation. The study notes the probable reason as wear and tear of the components. This suggests that although the turbines may last until their intended design lifetime, reductions in output may make large overhauls necessary after 10 to 15 years.
Refurbishment
- Different components of the wind turbine have different life expectancies. Moving parts such as the blades and the gear box have a higher failure rate than static parts, such as the tower. Likewise, exposed parts of the turbine are expected to fail more quickly than internal parts that are shielded from wind, rain and sun. Because of this, it may be possible to overhaul the more sensitive components to extend the lifespan of the turbine beyond its economic lifetime without replacing the entire unit.
Factors Affecting Lifespan
- The better quality the materials used to build the turbine are, and the better the build quality, the longer it can be expected to last. There are also several environmental factors that might affect the turbine's lifespan. The most obvious is the wind itself. Although the turbine is designed to last in the face of wind impact, the greater turbulence onshore versus offshore might affect lifespan. Air density, seismic factors and humidity may also play a role.

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