In Germany, more and more wind turbines are being dismantled. The reason: subsidies are running out, the material is worn out or it is simply more profitable to replace old wind turbines with new ones. The dismantling, however, is extremely complex and expensive.
This German wind turbine was toppled after 19 years of service, photo dpa
Across Germany, there are more than 25,000 wind turbines. A disfigurement of the landscape, say some; a symbol of the transformative power of Germany towards a power supply from renewable energy sources, say others. Germany experienced its first wind power boom long before Angela Merkel proclaimed the energy turnaround in 2011 and sealed the end of the nuclear reactors.
Already in the mid-1990s, wind turbines were built on a large scale in the Federal Republic. Because of this, many of the turbines have now reached a critical age. In the coming year, more than 7,000 turbines will be older than 15 years. Wind turbines are only designed for a limited service life. After 20 years of operation, they have to be shut down and dismantled – unless the owner can prove that stability and fatigue strength are passed.
“Most systems can easily be operated for several more years,” says Torsten Bednarz from the TÜV-Rheinland. The tests and certifications, which the TÜV carries out at wind installations, show repeatedly that often only minor repairs are needed at many locations in order to ensure the continued operation. Thus it is not so much the alleged disrepair of the turbines – which led to 544 of them being removed last years alone – as the question of whether their operation still makes economic sense.
After 20 years, the guaranteed feed-in tariffs for wind power expire. Without this fixed support, many systems are simply no longer profitable. In addition, it may already be beneficial to replace wind turbines that are only ten years old with new ones, says Dirk Briese, Managing Director of the Bremen market research company Wind-Research. “Today, there are entirely different technologies than there were a decade ago,” analyzes Briese. The performance of the turbines have multiplied, the turbines are also more efficient than before.
For offshore park decommissioning funds must be set aside
It is foreseeable that the dismantling of old wind turbines will increase rapidly in the coming years. But how can the turbines, which weigh more than one hundred tons and are 160 meter high, be taken apart anyway? “Amateurs blow them up or fell them like a tree,” says Alexander Brehm, project manager for large components at PSM. The company specializes in the maintenance, repair and dismantling of wind turbines. Per dismantled turbine the company charges up to € 30,000.
In fact, the dismantling of wind turbines is at least as complicated as their installation. With two cranes, every turbine is dismantled piece by piece. Turbines, rotor blades, tower houses and other components from discarded German wind farms are in great demand in Poland, Italy and Russia. At the second-hand market, they can obtain good prices.
Those who simply topple windmills, on the other hand, must firstly accept the loss of still valuable parts. Secondly, remainders of engine oil and heavy metals might pollute the soil. Even more complex is the decommissioning of offshore wind farms. After all, the steel pillars, which were rammed into the seabed, must be brought ashore again. The additional expenses due to the fact that all components must be shipped back on land are gigantic.
So gigantic actually that the operators of offshore wind farms have to hold millions of euros in provisions for the dismantling of offshore windmills. Unlike on land, the dismantling issue in the open sea will only come up in a few years because the first offshore wind farm in German waters went into operation only in 2010.
Translation Philipp Mueller