UBA study considers environmental aspects of the recycling of old wind turbines
More than 27,000 onshore wind turbines (WTG) are currently in Germany. At the end of 2020, facilities earning the 20-year subsidy under the Renewable Energy Sources Act (EEG) will no longer be covered for the first time. Depending on local conditions, older plants may be replaced by more powerful and more efficient new plants to allow for a higher yield at the site (so-called repowering). Also the continued operation of plants could come into question, if they are deemed less viable either technically or economically. So far there is very little experience with this issue. The Federal Environment Agency (UBA) has therefore examined the state of the art of decommissioning. In an extensive research project (see here or download from this page), UBA calculated recycling volumes and considered the financial cost of tearing down the facilities. The study found there are bottlenecks in the recycling capacities for the fiber-reinforced plastics of the rotor blades and risks to humans and the environment during improper dismantling. In addition, the provisions of the operators for dismantling may not be sufficient. According to Maria Krautzberger, President of the Federal Environment Agency, "The federal and state governments should quickly develop guidelines for the dismantling of wind turbines. We need clear targets for dismantling and removal methods in order to protect people and the environment and to recycle valuable materials."
The decommissioning forecast calculated the anticipated waste quantities during decommissioning from the year 2021 and onward. It was assumed that the average life expectancy of a system would be 20 years - and the possibility of continued operation was not taken into account. Under this assumption, concrete (above 5.5 million tonnes per year) and steel (just under one million tonnes per year) will be the main components of the decommissioning, as are copper and aluminum. However, these quantities are easily processed by the existing recycling infrastructure. There is uncertainty iregarding the recycling of the rotor blades. For composite materials including the blades, small quantities of waste are initially expected by around 2024. From 2025 onwards, relevant quantities of waste containing CFRP are expected to rise steadily in subsequent years and reach a maximum value of 73,500 tonnes in 2038. The composite material is more difficult to recycle. So far in Germany, there is only one recycling plant for GRP / CRP waste. Among other things, the study therefore recommends examining whether the introduction of specific elements of waste management product responsibility for rotor blades could make sense in order to create additional recovery capacities.
Operators of wind turbines have to build up monetary funds for dismantling. The study also calculated the expected cost of dismantling. This shows that, especially from the middle of the twenties, significant funding gaps are imminent: For the year 2038, a gap of more than 300 million euros is forecast. The study therefore recommends reviewing the basis of calculation of the funding and having the funds regularly audited by an independent expert to determine if they still reflect the state of the art and the expected costs.
The study also examines which regulations should apply to the dismantling of wind turbines. During decommissioning, environmental, occupational and noise protection have a high priority. When decommissioning and the removal of operating fluids and gases appropriate expertise must be present. Dismantling should always take place sequentially - blasting or demolition plowing should only be used in exceptional cases. Foundations, cable routes and paths should be completely dismantled. For sawing work on site, the dust load for people and the environment should be minimized by enclosing and collecting dust-laden water.
The multitude of different plant models and locations makes it impossible to develop a single and uniform concept for the dismantling of wind turbines. Therefore, the study recommends measures that on the one hand ensure the high ecological standard of the industry and on the other hand offer largely technology-open development opportunities. It thus summarizes framework conditions and provides direction for operators, companies and supervisory authorities entrusted with dismantling and recycling.
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