Wind turbines are enormous constructions. The idea of wind-powered energy is not very modern, but wind turbines are the modern counterpart of the ancient mills. At first, it wasn’t used on large or industrial scales.
In the early 2000s, the very first industrial wind turbine was installed. Since then, many turbines have been installed to date, and many are gradually reaching their end of life.
These huge constructions would cause massive wastage if they cannot be reused or recycled. So, what happens to them after the end of their life period? Let’sLet’s see.
Wind Turbine and its structure
While discussing green energy, wind energy is the second most popular (the first one is solar energy). The use of wind energy for generating electricity is not a new technology; rather, it is the rediscovery of the ages-old tradition of harnessing wind power.
Wind turbines are the most convenient way to harness wind power to generate electricity. It’s a standalone unit of a wind farm, and one turbine can’t produce a sufficient amount of energy.
Still, a wind turbine is the best option when the requirement is smaller. For more extensive needs, it’s common to see groups of turbines in small farms and even multi-megawatt large wind farms. Turbines are manufactured in different sizes and alignments.
It has three different components the rotor, the generator, and the surrounding structure. The rotor includes the blades. The generator consists of an electrical generator, the control electronics, a gearbox, an adjustable speed drive, or a continuously variable transmission component.
The surrounding structure is the tower and rotor yaw mechanism. The tower is relatively high, and the blades are also large depending on the power. For example, an 80 meters high turbine containing the rotors assembly weighing nearly 22,000 kg can produce 1.5 MW of electricity. In the case of a turbine large like that, the base is almost 15 meters in diameter.
Why do we need to recycle them?
Wind turbines are generally massive constructions. They take many places to exist and work. The components are also larger accordingly to the energy generation capacity. These large components make vast piles of waste after the end of their lifespan.
So it needs a considerable place to dispose of those wastes. Also, generally, the materials have much life and strength left even after the wind turbine stops working. A large portion of the materials is different metals.
Reusing them can supply the massive demand of metal industries. If these structures are left unused, they won’t only fill a vast land area but will also be a huge waste of suitable quality metals and high-strength composite materials.
Especially the blades are powerful as well as light. So they can help make strong and durable constructions.
Why are wind turbines not usually recyclable?
Wind turbine blades are predominantly made of steel, fiberglass, and resin or plastic. They are a sandwich composed of fiberglass, sheets of balsa wood, and a chemical called epoxy thermoset resin.
They are made too strong so that they can withstand hurricane-force wind. Being so strong, they are hard to crush, recycle, and even reuse. The average lifespan of blades is 20 years.
After the end of their lifespan, they are being useless wastes and getting piled up. Also, they are huge in size. They end up in landfills o are burned. Besides this fact being true, we should also remember that technology is advancing.
And though the process of recycling blades is hard but isn’t impossible. Recycling specialized carbon composite materials is 20 times more expensive than recycling metals, making it challenging but not impossible.
Being that much huge, they are also difficult to carry and transport. Also, burning fiberglass emits pollutants that are a threat to the environment. The metal components are the easiest and safest to be reused.
The concrete ones still go through a significant loss in quality. The University of Strathclyde estimates that by 2050 there will be 2 million tonnes of wind turbine waste needing safe disposal globally.
What is the world thinking about recycling wind turbine blades?
I previously mentioned the materials that those blades are made of. To make them stronger and more sustainable, they aren’t made of pure metal. This is something that makes them hard to be recycled.
Anyway, there are still ideas to recycle and reuse them. In a pilot project, it was tried to grind them to dust, looking for chemicals to extract. One start-up, Global Fibreglass Solutions, developed a method to break down blades and press them into pellets and fibreboards that can be used for flooring and walls.
In Texas, there was another operation planned in Iowa. “We can process 99.9% of a blade and handle about 6,000 to 7,000 blades a year per plant”, said Chief Executive Officer Don Lilly. The company has accumulated an inventory of about one year’s worth of blades ready to be chopped up and recycled as demand increases.
One French research project (ZEBRA) aims to launch 100% recyclable wind turbine blades within the next three years. They consider all possible ways like new material development, blade manufacturing, operations, and decommissioning.
In the port city of Aalborg, they found an innovative idea of turning the old blades into bike shelters. This has been helpful as the Scandinavian climate can be hard on bikes, especially in winter. Also, bikes are a prevalent kind of transport there.
In Ireland, University College Cork plans to build a bridge on a greenway (across the Midleton to Youghal Greenway in East Cork) on the track of an old railway lineout of those decommissioned old turbine turbines blades.
They will have 11000 tonnes of those blades needed to be disposed of within the next four years, and that will be a huge waste if they cannot be reused by any means. This will be the second bridge in the world made of rotor blades.
Last October, the first one was built in western Poland and officially opened in early January.
How does Germany recycle wind turbine blades?
Wind energy being Germany’s most important power source, they need the process of recycling and reuse of the different components of wind turbines the most. Also, that process must not cause any harm to the environment.
To dismantle such a large quantity of turbines is really a challenge. According to the wind industry lobby group BWE, nearly 90% of the weight of a turbine can be recycled, especially the metal and concrete parts. Plastic, resin, or composite materials are still problematic to recycle.
Turbine deconstruction actually needs some tailored plans as wind turbines have a diverse range of installation and removal concepts. There is a range of govt. Cofounded projects aimed at improving and streamlining deconstruction and recycling procedures.
Turbines that are taller than 150 meters are difficult to dismantle. For example, construction cranes that can lift heavy machinery are rare in supply. So the deconstruction process itself becomes difficult or costly for them.
Those Govt. cofounded projects can hopefully put some light on this problem very soon. For example, cutting down the concrete towers will take one week rather than eight.
The towers can be torn down into several pieces or be made to fall with a targeted detonation. The foundation is then thrashed out from the ground and gets piled in place. Removing them can lead to unnecessary damage to the soil structure.
The concrete can be used in road constructions and other constructions. But reusing the concrete for other purposes is still tricky as the quality diminishes with time. Blades are removed then and mostly be cut on the spot. Fiber-enforced plastics are prevented to blown into the air as they can cause air pollution.
The metal parts and composite or plastic parts are then made separated. Metals like copper, steel, and aluminum are molten down. These same metals can be reused for such wind turbine construction and other purposes.
They are just the same as useful as they were earlier. So it’s no issue reusing them as no significant quality loss is noticed. Also, it ensures energy saving as reusing them doesn’t demand as much energy as the mining and production process and also is less expensive.
Reuse of wind turbine blades
The first I’ll like to say about the infrastructures made or planned to be made of wind turbine blades. Earlier I told you about bridges made of turbine blades.
They save the environment and find one sophisticated way to repurpose the blades and strengthen the infrastructure (blades are made to withstand tornados!).
It saves the energy required to make new construction materials. If one talks about the quality of materials, then we should know that blades often have left with decades of life left in them even after being decommissioned.
Siemens Gamesa blade factory in Aalborg, Denmark, has produced the world’s first 81-meter long recyclable blades for wind turbines that can be completely recycled after their lifespan.
Wind turbines with more than 200 GW of new offshore capacity are projected by the Global Wind Energy Council to be installed by 2030. Siemens Gamesa is introducing the technology with which separation of the materials in the blade is possible at the end of its lifetime. It’s a new milestone in the sustainability of green energy. (siemengamesa.com)
After four years of research, the NREL wind technology center introduced a new blade. The new blade uses most of the components similar to the old ones.
Still, it sandwiches them together with a thermoplastic resin (Elium, made by Arkema Inc.) instead of epoxy thermoset resin. It hardens the blades and can be set to shape at room temperature.
The materials can be regained after the end of their life by simply melting them into liquid. These can also be used for new blades, minimizing the waste problem.
CETEC has developed one new technology that aims the journey toward fully recyclable blades. The strong bond between epoxy resin and fiber is what makes it so difficult to regain the materials and reuse them.
With the novel technology of CETEC, it will be possible to capture the value represented by each material in a new circular value chain. This is a two-step technology. At first, the composite is dissembled into fiber and epoxy.
Then the epoxy is further broken up into its base materials through a novel chemical recycling process so that the materials can be used as virgin materials again.
Superuse Studios, a Netherland-based company, has developed interesting infrastructures and constructions of reused blades. They have done projects that designed playgrounds and benches out of turbine blades.
Nowadays, making pedestrian bridges or low traffic bridges of old turbine bridges is a hot idea. In many countries, many research projects and many engineers are working to make the idea or design of this kind of bridge more feasible and trustworthy.
There are ideas and designs under development to make outdoor furniture and playground infrastructures using old turbine blades. These are popular in different countries.
Can we recycle other parts of wind turbines?
Some parts of wind turbines definitely can be recycled. Nowadays, almost 85% of components of a wind turbine are recyclable. With the growing technology, we hope the percentage to increase.
Most of the parts that are made of concrete, steel, copper, and cast iron are easy to recycle. The foundation, tubular steel towers, gearbox, generator, etc., are parts that can be recycled.
As we know, wind turbines vary in size depending on their intended application. There are both large industrial scale models and small domestic models.
Large models are more difficult to recycle than domestic ones. But there are certain parts in those domestic ones that are somehow difficult to dispose of.
How to recycle different parts of a wind turbine?
To withstand the high speed of the wind, the base structure of wind turbines needs to be huge. The turbines’ foundations are engraved deep inside the ground, and the excavation is at least 10-feet for one standard size turbine.
It needs to be filled up with nearly 500 cubic meters of cement, and the fabrication of the reinforcing cage requires 68 tonnes of steel. These constructions can be reused when the wind turbine is no more useful.
Tubular steel towers
Towers of wind turbines are not just column-like shaped. Rather they are conical in shape, i.e., with more comprehensive bottom parts and narrower towards the top.
Large bottoms give greater stability, whereas narrower tops simply reduce the amount of steel required for construction.
So the towers contain a huge amount of steel that can be reused. Being high-quality steel, they are also very high-valued in the metal industries.
Each tower has several parts or pieces, and separating these parts from each other makes the transportation process easier. Each tower contains nearly 65-100 pieces rich in high-quality steel.
The gearbox is a component of a wind turbine that increases the rotational speed of shafts that connects to the generator.
Usually, they are made of metals like steel, aluminum, or brass. The gearbox is found between the blades and the generator.
There are different gearboxes, and each contains a good amount of metal. So, gearboxes can be recycled.
The generator is the component that converts mechanical energy to electrical energy. We need permanent solid electromagnets to construct this part.
Such high-strength magnets are typically constructed from rare earth materials like Samarium Cobalt, Neodymium iron, etc. Also, it contains coils to conduct electricity.
The wires and coils can be recycled as they are made of conducting metals, and those rare earth magnets are also recyclable.
Wind energy is one of the world’s fastest-growing renewable energy. But this too isn’t free of disadvantages. It is very crucial to scale the wind industry sustainably. Many research teams and companies are out there aiming to produce zero waste wind turbines.
Otherwise, it will be a significant barrier in the path of the growing wind industry. Wind energy has a great future in supplying the world’s massive demand for energy if we can clear the hindrances in the path.
One of the greatest hindrances is the blades piling up and having no other easier than dumping them in landfills. So the whole wind industry is now behind this thing and coming up with different ideas of recycling and reusing them or making recyclable blades. Now we can see there are several great ideas are there too.