When wind turbines retire

Whereas human beings are just reaching adulthood at 20, wind turbines tend to retire at that age. After two decades of service they are either sold on to the second-hand market or dismantled at the end of their useful life. While the tower and nacelle consist of concrete and steel, which are easily recycled, until recently it has been impossible to properly dispose of the rotor blades.

The blades are largely made up of glass-fibre-reinforced plastic (GFRP), which doesn't decompose in landfill sites, and cannot be burned either, as the fine fibres clog up the incinerator filters. So far the disposal of rotor blades hasn't been much of an issue, because the building boom in the wind power industry only started in the early 2000s. But around 2020 the first wind farms will be reaching the end of their useful lives, creating a growing demand for disposal solutions.

neocomp recycles glass-fibre-reinforced carbon

Hans-Dieter Wilcken is already preparing for that time. The managing director of disposal specialist Nehlsen, based in Bremen, set up the company neocomp GmbH, the only facility for glass fibre recycling in Germany. "The Federal Government/Federal States' Working Committee on Waste (LAGA) has awarded our process the status of best available technology – that is a very special accolade for us," he says proudly. Another acknowledgement came in the form of a prestigious environmental award, the GreenTec Award, which the two-year old company received in autumn 2017.

Securing market advantage

"Developing new processes in the waste management industry is very challenging," Wilcken goes on to explain. Competition is fierce, the price war is tough, and the legal entry barriers are high. New processes struggle to prevail over existing ones. According to Wilcken, a greater degree of environmental compatibility could just tip the scales. Manufacturers in the 'green' wind energy sector in particular are increasingly keen on ensuring an eco-friendly supply chain – including the disposal stage.

Rotor blade recycling: turning glass into cement

During a guided tour, Wilcken explains that neocomp employs 'brute force'. The centrepiece of the plant is a huge shredder, which gradually breaks down the glass fibre components until they are the size of shredded paper. Then they are mixed with paper production residue generated during waste paper recycling, such as plastic labels, plastic bands and packaging materials, all of which cannot be used in paper production. The mixture is turned into a fine granulate that makes an ideal additive for cement production. A cement factory in Lägerdorf, Schleswig-Holstein, processes the ingredients from Bremen. In the cement, the GFRP mixture becomes part of a chemical compound, with no discernible residues. Total recycling.

Facility is ready to meet national demand

At the moment, the young company with its six employees can process 30,000 tonnes of glass fibre annually. That is significantly more than is currently being produced by the wind power industry. "Our plant is ready to meet the nationwide demand over the coming years," says Wilcken. In order to operate economically, neocomp also accepts GFRP remnants from other sectors – such as the construction materials industry, engineering and vehicle manufacturing.

Making waves internationally

In the meantime, word has got around about the eco-friendly disposal of GFRP components. A Danish wind turbine manufacturer has chosen neocomp as their disposal partner – despite the costs being slightly higher than for the landfill option, which is available in Denmark. "In future, we are hoping to cooperate with all major manufacturers. To this end we offer professional dismantling on site, in addition to environmentally responsible disposal," says Wilcken.

Start-up character drives innovation at Nehlsen

For Nehlsen, setting up a start-up like neocomp is an important aspect of keeping one step ahead of the competition. "We can bring new processes to market very quickly, the start-up nature of our company helps us to be dynamic. Our aim is to ensure that we avoid waste – ideally altogether," Wilcken explains. And he already has his eye on the next material that presents a high level of difficulty at the disposal stage – carbon-fibre-reinforced polymers (CFRP).

More articles on wind power are also listed in our topics overview.

For more details on wind energy, please contact Dieter Voß, Senator for Economic Affairs, Labour and Ports, Department of Industry, Innovation, Digitalisation, tel: +49 (0)421 9600 328, dieter.voss@wah.bremen.de.