With numbers of wind turbines reaching the end of their useful life now moving into the thousands each year, industry is drawing up strategies to deal with the wave of waste. Blades are posing the biggest challenge
Article updated on September 13, 2018 If facing the reality and inevitability of death is a sign of maturity, wind turbine designers, manufacturers and operators have, as it were, well and truly reached old age. No longer is it hundreds of onshore turbines from the early years of wind energy entering their graves, but thousands as they reach the end of what for most is their useful 20 to 25 year lives. In Europe, wind turbine age data, which has been compiled for 69% of the continent’s 169 gigawatt (GW) installed capacity, shows that 3% of wind turbines are 20 to 25 years old, 15% are 15 to 20 years old and 23% are between ten and 15 years old, according to industry association WindEurope. In contrast, just 14% of the 89 GW wind fleet is over ten years old in the US, according to the American Wind Energy Association. Older wind turbines are being decommissioned and increasingly refurbished, prompting efforts by industry to work out what to do with disused parts. Turbine foundations, towers and gearboxes can be largely recycled, according to WindEurope, whereas blades pose considerable challenges. They are predominantly made of a combination of fibre and polymers, known as fibre reinforced polymer (FRP) or glass reinforced polyester, as well as various plastics, coatings, metal and wood. “These give the blades aerodynamic and structural characteristics such as high tensile strength and resistance to fatigue,” says Mattia Cecchinato of WindEurope. “But it is difficult to return these materials to their original form without consuming a lot of resources.” The association has set up a task force to deal with the issue of blade waste and in March 2017 published a discussion paper on the issue. This shows the wind industry is one of the fastest-growing consumers of FRP composite in the world. There was a three-fold increase in the amount of it used annually by the industry between 2000 and 2016, based on the assumption that turbines use 12 to 15 tonnes of it per megawatt of wind energy produced. WindEurope predicts the industry will use about 180 tonnes of FRP composite a year up to 2030. These projections mean the first large wave of blade waste is about to arrive, says Cecchinato. WindEurope is updating its blade waste estimates by cross-checking with wind farms.
Disposal methods
In Europe old blades are dismantled, removed and treated by waste contractors operating according to local regulations, says Cecchinato. According to the WindEurope paper, jaw cutters are the most commonly used machinery for chopping the blades into smaller sections, producing dust and fibre emissions. “It is also necessary to sanitise the area after completion. The sections are prone to emit dust and fibres during transport, which increases the demand for proper stowing and protection on lorries,” the report states. When not recycled, these sections of waste blades are buried in landfill sites or incinerated in Europe. In Germany and the Netherlands there is a landfill ban on composites, while in other countries the material is subject to landfill taxes. The cost and responsibility of decommissioning turbines falls to the wind farm developers, who are required to submit decommissioning plans at the permitting stage, says Cecchinato. “The decommissioning of wind turbines, if not correctly undertaken, can lead to environmental impacts,” admits the European Commission, the EU executive body. It does not, however, plan to present any initiatives related to wind turbine decommissioning since broader legislation such as that on waste and the end-of-life treatment of materials and guidance already exist.
Recycling options
“Recycling capacities have been increasing and recycling methods have been maturing in order to accommodate the expected amounts of blade waste,” says WindEurope’s discussion paper. “Further, waste policies and the demand for wider producer responsibility are also increasing.” Alla Swets and Cora Burger set up Demacq Recycling International in the Netherlands to deal with the burgeoning mountain of composite waste. The women have many years’ experience in the maritime and demolition worlds respectively. “We don’t believe in burning or in dumping,” says Burger. “The calories you get from burning it are quite low and as normal incinerators only reach 600-800 degrees [Celsius] they will burn the resin but not the glass fibre.” Demacq has found a way of recycling waste blade composite, without burning or applying chemical processes, enabling the so-called “recyclate” to be used again, though the company will not reveal its method. “We use mobile equipment which is a totally dust-free concept and completely safe,” says Burger. “It was specially developed because a lot of turbines are on farmers’ land and they don’t want particles flying around. The glass fibres can last for 500 years.” She adds: “I have seen pictures of how some people are cutting up old blades leaving a mess, soil that needs to be rehabilitated and creating dust which is a skin irritant. It is always better to prevent this.”
We need to get started with a system where the original factories that make the turbines take them back, in a similar way to used cars being returned to automobile manufacturers
Useful mobility
By using a mobile unit to break up the material onsite, Demacq cuts transport costs and associated emissions. “If an old blade needs to be moved intact the transport costs are the same as if it were new,” says Burger. “With our system we can get several blades in one normal truck which saves the environment.” The mobile unit also speeds up the reuse process. “We can recycle on the spot so reusers can pick up the recyclate straight away. We can process 50 tonnes an hour. There are no limitations. It’s simply a matter of upscaling.” The company is actively seeking to promote its solution internationally and has this year been in discussions with Djurs Wind Power and the port of Grenaa, both in Denmark. The reuse industry is a strong partner and the concrete industry in the Netherlands is enthusiastic about the testing it has done using Demacq’s recycled glass fibres for reinforcing concrete, says Burger. Recycled composite is also used for bridge building, river-bank protection and furniture making. “Composite river reinforcement saves on tropical hard woods, the maintenance is almost nothing and it will last for 50 years or more. That’s why this end-use of recycled composite can be considering up-cycling,” says Burger. She is spurred by a desire to create a circular economy. “We need to get started with a system where the original factories that make the turbines take them back, in a similar way to used cars being returned to automobile manufacturers.”
Circular economy
The push for circular economy principles is coming from the European Commission, says Mattia Cecchinato from WindEnergy. “The big challenge is how we can give blades higher resistance [to corrosion and fatigue, for example] while still being able to recover the materials at the end of their life.” WindEnergy will host a dialogue at the 2018 Wind Expo in Hamburg between blade designers, manufacturers, operators and waste recyclers, to discuss the challenge. “There needs to be a focus on blade design and material selection so that at the end of their life blades can be easily treated,” says Cecchinato. Indeed, optimising the life-cycle of wind farms is one of three priority programme areas for research funding called for by MegaVind, a Danish wind energy platform for research, innovation and technology. MegaVind has also identified the efficient re-use or disposal of blade materials as requiring significant research and innovation efforts if Danish industry is to stay competitive. “There’s a big market for companies that can develop systems and methods to reuse glass fibre,” agrees Glenn Aagesen of FairWind, a global provider of one-stop solutions for onshore and offshore wind turbines, highlighting the significant volume of old blades that will have to be dealt with. “There are already some prototypes in place and in the future this glass fibre will be used for something instead of just scrapping it for garbage.” As to requiring the original turbine manufacturer, if still in business, to take back their products when these reach end-of-life, Glenn Aagensen says: “Yes, why not? I think it’s an interesting thought.” Proof, surely, of the voice of a mature industry.
Writer: Iva Pocock
End-of-life turbines
Foresight Climate & Energy asked four of the world’s leading turbine manufacturers — Vestas, Siemens Gamesa, Goldwind and Nordex — for their response to the suggestion they could be responsible for turbines they manufacture when they reach the end of their lives, and whether this is something they are considering. Vestas said 80% of a turbine is recyclable and that disposing and recycling of end-of-life wind turbines rests with wind farm owners rather than manufacturers. “We work with industry organisations in collaboration with other manufactures to increase that percentage,” said the company’s Annika Balgård. “We provide documentation to our customers on how to ensure recycling of turbine materials and work on developing new sustainable materials that can be reused and replace non-recyclable materials.” Goldwind said traditional incineration and landfill of waste blade causes environmental pollution that cannot be ignored. “It is necessary to recycle old blades and other components after wind turbines are decommissioned,” said a spokesperson, adding the company has been recycling the permanent magnets used in its turbines by using the scrap magnet for smelting to make new ones. After investigating feasible disposal options the company considers the physical comminution of blades, by which they are cut into smaller pieces, as the most likely option to be commercialized. “Goldwind is actively exploring and promoting environmentally-friendly product design, full lifecycle wind farm services and possible applications for comminuted blades,” said the spokesperson. Nordex’s Ralf Peters said that legally, the current situation is absolutely clear. “When the turbines are sold, responsibility for dismantling them passes to the owner of the turbines. Even so, we feel responsible for the turbines we produce and, as the manufacturer, participate in efforts to find industry-wide solutions.” He added: “This concerns the extension of the operating period, heightened efficiency during operation and dismantling of the wind power systems, in other words the disposal and recycling of its components.” A spokesperson for Siemens Gamesa said manufacturers have a legal responsibility to provide information about the characteristics of the waste and the recyclable materials at the end of a product’s useful life. The company foresees more onerous regulation coming on stream in 2020 and is already working on the recycling of glass fibre, carbon and composites.
This article is part of a series published by FORESIGHT Climate & Energy in the lead up to Global Wind Summit 2018, held from 25-28 September in Hamburg, Germany.