Recently, there have been many discussions behind the scenes about potentially setting a limit on the height of wind turbines. A height limit should stabilize the development and manufacturing process and allow for more sustainable operations. A workgroup on the issue recommends a maximum height of 1,000 feet, or 305 meters, for new wind turbines. Hans Rijntalder, chairman of Pondera Group and NWEA’s offshore committee, is closely involved with this development.

The energy transition is in full swing, and with it come the developments of wind turbines. Because tall wind turbines catch more wind and thus generate more electricity, new wind turbine models increase in height. However, this development has started to create problems, for example with supply companies. Hans Rijntalder discusses the tricky situations that arise: ‘It can now happen that a contractor orders an installation ship and by the time it is built, the ship has already become too small to install the turbines being built at sea. By comparison, a ship normally easily lasts about 20 to 30 years before it needs to be replaced.

Standardization

In other words, the almost exponential growth of wind turbine size poses problems for the supply, installation and reliability. In addition, turbine manufacturers are facing high costs as they are forced to invest heavily in developing new turbine models to compete. Rijntalder: “Standardization of turbine height can increase the stability of the industry – wind turbines and suppliers – and this in turn leads to a better investment climate for developers and investors. Ultimately, this will bring the energy transition to fruition faster. An additional benefit could be that more attention and money is invested into using sustainable materials and making turbine blades circular.’

It is also important for nature preservation objectives that turbines are not significantly different from each other; similar turbines make it easier to monitor and compare the impact of wind turbines on ecology and species over several years and projects.

1000 ft

So where does the 305 meter limit come from? Rijntalder: “1000 ft is a well-known measure of airspace; for example, an aircraft should not fly less than 1000 ft above buildings. Because it’s a known order of magnitude, it increases the likelihood that countries will adopt it internationally.’

And it is critical that the limit is adopted internationally as the proposed strategy is not risk-free. If only the Dutch industry limits itself to 305-meter turbines, there will be a disparity between the Dutch market and the broader European market. This could mean a worse business case for the Dutch market and difficulty for Dutch ports with facilitating larger turbines for other countries. In addition, it is expensive and inefficient for producers to produce both models for the Dutch market and for countries without a height limit. Therefore, it is crucial that the proposal also receives attention and is discussed at the European level. “It seems that the European initiative is going to support the Dutch initiative. The intial indications appear to be positive,” Rijntalder said.

The current proposal has a deadline until 2037 with an evaluation round scheduled for 2028.