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Onshore wind

Wind energy

Wind turbine manufacturing and components

WindTech refurbishes 3 secondhand 50 Hz wind turbines into new 60 Hz wind turbines

23. February 2021

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WindTech A/S
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Today the wind industry is progressing faster than ever before.

Every year more and more turbines are installed both offshore and onshore. These modern wind turbines are often several times more efficient than their predecessors. But it's still important to remember the old wind turbines built 20 years ago. These older wind turbines are often replaced with newer and more efficient models and afterwards discarded.

This is despite the fact, that a complete refurbishment can often revitalize and modernize an older wind turbine. This can in turn extend the life expentancy to upwards of 20 additional years!


At the end of 2020, the Canadian firm, Free Breeze, bought 3 Italian secondhand Vestas V47 wind turbines from 2004. These turbines, which would have otherwise been discarded, would be given a full refurbishment in Denmark and shipped to a Texas wind turbine park, owned by an American energy corporation.

After Free Breeze contacted WindTech and chose us to perform the refurbishment, WindTech received the old Vestas V47 wind turbines from Italy. The extensive refurbishment project was estimated to run approximately 8-12 weeks. During this time, WindTech would disassemble the nacelles completely to access the main components. The main components are usually subject to extensive wear and tear during their use. Because of this, the main components were subjected to thorough tests and measurements.

After the preliminary tests were done, the real work began. Disassembling and refurbishment is nothing new to WindTech. The main challenge in this project however, was that the refurbishment included the transformation of the original 2004 50Hz turbines, into the standard 60Hz turbines used in the US. Not only is this kind of refurbishment incredible extensive, but it is also very complex.

Since the 50Hz EU wind turbines and the 60Hz US wind turbines are incompatible, some parts must be replaced to work with the US energy infrastructure. This process primarily involves replacing or renewing the gearbox, the motors, and the control system. After the complete disassembly of the nacelle and its main components, WindTech cleaned and washed every component. After this, the components were ready for inspection for wear and tear damage. Some parts were refurbished, and some components had to be replaced with the new 60Hz parts. WindTech always uses high-quality bearings and components in our refurbishment process. Afterwards, the components were reassembled and painted, and the final tests were initiated. Finally, the nacelle was reassembled and the whole process was checked thoroughly.

Once the project was done and the nacelles had been completely refurbished, transformed, and assembled, they were shipped to their destination. In this case, to Houston, Texas. The nacelles are expected to reach the US around the end of July.