Dismantling of wind turbines

Why do wind turbines have to be dismantled?

On closer inspection, operators have to deal with the topic of dismantling even before commissioning their wind turbine or wind farm, even though there are still many years and gigawatt hours of electricity ahead of their project. The reason lies in the legal regulations that apply to dismantling. Usually, wind turbines are erected in the so-called outdoor area, where they may be operated as "privileged projects" according to § 35 para. 1 no. 5 BauGB. A little further in the text of the law is the decisive passage (§ 35 para. 5 sentence 2 BauGB) on the subject of demolition:

„Für Vorhaben nach Abs. 1 Nr. 2 bis 6 ist als weitere Zulässigkeitsvoraussetzung eine 

Verpflichtungserklärung abzugeben, das Vorhaben nach dauerhafter Aufgabe der 

and to remove soil sealing [...]."

This means that in order to obtain a building permit for the project at all, the operator(s) must commit to the complete dismantling of the wind turbines, including the foundation. With the dismantling obligation, provisions or a security deposit must also be deposited, for example in the form of a dismantling guarantee. On the one hand, this prevents the dismantling from being financially covered in the event of insolvency or a change of operator and the costs from being borne by the general public or the property owner. On the other hand, the wind turbine should not remain in place after its intended service life as a monument to the energy transition and the site should be restored to its original state. ↑[top]

What factors determine the costs of dismantling a wind turbine?

Each wind project is built under individual conditions and influencing factors, which in turn has an impact on dismantling costs. Among other things, the question of location is important here. Is the site easy to reach for cranes, heavy transport, etc.? How much effort is required for the access road? To what extent will earthworks and renaturation be carried out? Is it a single turbine or a connected wind farm? In the latter case, further costs would then be incurred for the dismantling of ancillary buildings, for example a substation or a transfer station. Where wind turbines are dismantled, disposal costs are also incurred, which can vary from region to region. The amount of proceeds from scrap metal and electronic waste, which is used to partially compensate for the dismantling costs, is also very dependent on the economic situation.

Possible changes in legal requirements can also sometimes have an impact on disposal costs and thus on the overall dismantling costs. And last but not least, it depends on the system itself that is to be dismantled: Which model is it? What hub height does it have? What components do the components to be dismantled consist of? After all, it makes a difference in terms of scrap revenues whether the plant has a steel, concrete or hybrid tower, not to mention the different amounts of steel, copper, aluminum and electronic waste depending on the model.

The amount of steel produced during dismantling is not to be sneezed at

Overall, the costs for the dismantling of wind turbines can be roughly summarized as follows:

• Crane costs (mobilization costs and costs per working day)
• Carriage
• Costs for shredding and disposal of rotor blades and nacelle (up to 30% of total costs)
• Disposal costs for hazardous waste materials
• Costs for foundation dismantling, disposal and backfilling with topsoil
• Costs for earthworks (crane parking areas, access roads, renaturation)
• Personnel costs

On the other hand, there are revenues from:

• Steel
• Copper
• Aluminium
• E-waste

According to a frequently cited rule of thumb, dismantling costs of around €30,000 per megawatt of nominal output are expected in the onshore sector. Operators therefore benefit from good cost compensation for dismantling if they have found a buyer for their used wind turbines or can at least sell individual components on the secondary market. ↑[top]

How high do the provisions have to be and how is the security deposit calculated?

For the calculation or the amount of the provisions that must be formed in the course of the dismantling obligation, guideline values apply, which are calculated differently from state to state.

In Brandenburg , the security deposit is one tenth of the shell construction sum, which in turn is set at 40 percent of the construction costs. This ultimately corresponds to four percent of the construction costs.

The wind energy decree of North Rhine-Westphalia states in point 5.2.2.4:

'Unless otherwise demonstrated, a security deposit in the amount of

 6.5 percent of the total investment costs can be assumed. In individual cases,

the construction of the wind turbine results in a higher or lower safety performance."

In Schleswig-Holstein , the amount of the provision is calculated from 10 percent of the shell construction costs or four percent of the construction costs including VAT.

No permit without dismantling obligation and security deposit

According to the dismantling decree of the state of Hesse , on the other hand, a formula is used to calculate the security deposit, namely the hub height of the wind turbine in meters multiplied by 1,000. The appropriate security means are also discussed here:

"The unconditional and indefinite, self-imposed (i.e. limited to the

rede der Vorausklage wird verzichtet) - Bank-, - Versicherungs-, - Kautions- oder - 

Group guarantee on first request."

In justified exceptional cases, security deposits in money or fixed-interest securities (e.g. savings account), fixed-term deposit accounts (termination only by licensing authority, notice period < 6 Monate) oder Verpfändung von Gegenständen und Rechten (zum Beispiel einer Grundschuld) zulässig.↑[top]

When does the dismantling of a wind turbine have to be carried out?

In principle, the estimated operating life of a wind turbine is 20 years, at which point the EEG subsidy usually expires. If it is not continued to be operated or replaced, dismantling is already pending. However, it is not uncommon for turbines to be replaced by more powerful models as part of the repowering process and therefore dismantled correspondingly earlier. Between 2013 and 2015, for example, the average age of a decommissioned or repowered wind turbine in this country was about 16 years.

However, there are also many cases in which wind turbines continue to be operated beyond 20 years and are far from being scrapped. One example of this is the Danish "Tvind" – the oldest large wind turbine in the world and in operation since 1975. Despite their proud age, dismantling is likely to take a few more years. Usually, however, 25 to 30 years of service is the feasible average with good care before it is finally dismantled. If, on the other hand, a plant is hit by a fire or an accident, dismantling ends up on the task list rather unexpectedly and earlier than planned. ↑[top]

Which companies are involved in the dismantling of wind turbines?

What work has to be done during dismantling?