Wind energy is green energy. It replaces dirty, fossil fuel derived electricity with clean, infinite wind power. Wind turbines can even be recycled! Well… mostly.
While the tower and generator can be recycled, it’s tough to find a second life for the blades. They’re made of materials that give it a lightweight and aerodynamic body, which is perfect for gliding in the wind, but hard to dispose of.
As the first generation of wind turbines starts to age out, wind energy experts are teaming up with manufacturers to figure out how to make future turbine blades more sustainable. Some organizations are even using the old turbine blades to make benches, playgrounds, and bridges.
What are Wind Turbine Blades Made of?
Most of the body of the wind turbine is made of reinforced steel, namely the tower. The generator and gearbox are also composed of several metal alloys. In contrast, the blades are made of a composite material consisting of glass fabric and carbon fiber infused with liquid plastic. This material gives the blades the special properties it needs to do its job.
The composite material is strong, lightweight, and has a low density. It can withstand the stress of constant rotation and speeds of over 100 miles per hour. It can also bend and warp when necessary but still has the tensile strength and stiffness to remain in its rotational plane. The composite material also gives the blades a low rotational inertia, meaning the blades can respond quickly to changes in wind speed, unlike higher density metal alloys.
The mix of materials changes depending on the size of the turbine, and their location (such as those on offshore wind farms requiring materials more resistant to salt). Larger turbines need stronger blades that can withstand higher speeds and avoid bending. This is because turbine blades that are too large can potentially bend out of plane and collide with the tower.
How Long do Blades Last?
Wind turbine blades don’t last as long as the turbine itself. Whereas wind turbines may last between 20 to 30 years, the blades may need to be replaced in 10 or 15 years. This depends on the local environment, as harsher conditions will cause faster degradation. Simple things like dirt, dust, and salt spray cause the leading edge of the turbine blade to erode, which lowers its aerodynamic properties. Storms also bring lightning, hail, and strong winds, which can cause microfractures in the blade structure, or even freeze the blades from the inside out. These microfractures can cause structural failures if left unattended.
Can Old Blades be Recycled?
The composite materials that allow the blades to be efficient and aerodynamic pose a problem; they aren’t easily recycled. The blades are essentially made of fiberglass, and once torn apart, it’s hard to fabricate them into refurbished materials.
This stands in sharp contrast to the rest of the wind turbine. The steel from the tower can be melted down and reused. The gearbox and generator components inside the nacelle can be scrapped as well. In all, about 85% of the body of a wind turbine can be recycled.
What Happens to the Old Blades?
The wind industry is relatively young, so the problem of recycling old turbine blades has yet to be fully examined. Currently, many wind farms dealing with how to scrap old blades are all doing the only thing they can, just letting them pile up.
These “turbine cemeteries” have been popping up all around the Midwest as engineers and entrepreneurs collaborate on how to find a cost-effective and environmentally friendly way to dispose of the old blades. Recycling is the preferred option, as wind turbines are supposed to help fight against climate change, not contribute to it. In some parts of the Great Plains, landfills have had to turn down blades or develop creative solutions to make them fit. They’re just so big, there’s simply not enough space. Even industrial-sized compactors are unable to break them down. One landfill tried cutting the blades up into thirds and stuffing the smaller pieces into the larger ones.
Not only are the blades huge, but there’s a whole lot of them too. There’s usually three per turbine, and with thousands of turbines going up all across the world, the number of blades that are going to need to be disposed of is massive. According to some estimates, around 8,000 turbines per year are going to be replaced over the next three years in the US. That’s 24,000 blades. Perhaps, at this rate, bladeless wind turbines will have to be relied upon more and more.
In Europe, where space is limited, and wind energy is more established, companies have taken to selling their old parts to customers in Latin America and Asia.
Solving the Problem
A few start-ups have sprouted up that are attempting to find solutions. Global Fiberglass Solutions, based out of Texas, is grinding down old turbine blades into small pellets and building panels that can be used for construction and manufacturing. The company hopes to have its products used for decking materials, pallets, and pipes.
Some people are getting creative. Re-Wind is a partnership between university students in America and Ireland, and they’re looking to repurpose wind turbine blades for civil engineering purposes, like bridges, towers, and materials to be used for emergencies.
Organizations in the Netherlands have also repurposed old blades into public works projects. Wikado Playground in Rotterdam uses old blades for children to play in, and another playground in the city of Terneuzen followed suit. Old blades have also been used as bus stops, benches, and there are even plans to build a bridge in the Danish city of Ålborg.
Wind turbine companies are also tackling the problem in the best way they can, right at the manufacturing plant. In the EU, Wind Europe, Cefic, and the EUCIA are consulting with engineers to fabricate composite materials which can be more easily recycled and last longer, all while still having the properties necessary for turbine blades to function. Wind energy leader Vestas has also committed to manufacturing zero-waste turbines by 2040.
GE recently teamed up with Veolia, a French recycling and environmental restoration company, to recycle the blades for its onshore wind turbine. The two companies even signed a contract, so this isn’t just small talk. Veolia has an innovative idea to recycle the blades. They plan on shredding them up into a material that can be used to make cement. According to Veolia, over 90% of the blade will be recycled, and their recycling process results in a 27% reduction in CO2 emissions when compared to traditional cement manufacturing techniques.
The blades are the bread and butter of the wind turbine. They capture the wind’s energy, spinning the generator and providing power to millions of homes all across the world. Unfortunately, they’re hard to recycle. They’re made of a tough composite material consisting of glass and plastic, which gives them the strength to withstand constant rotational speeds well over 100 miles per hour. As old turbines are decommissioned, turbine blades are piling up in wind turbine “graveyards.” The problem is forcing wind and recycling companies to develop innovative solutions, such as public works projects where the blades are repurposed into benches or playgrounds. A few start-ups are even using the old blades to make textiles and cement. Being that wind energy is so new, we’re still at the forefront of how best to deal with wind energy waste.
Frequently Asked Questions
Wind turbine blades aren’t as easily recycled as other parts of a turbine. While there’s an established market for the steel and metal alloys in the tower and generator, companies have yet to figure out how to properly recycle the fiberglass blades.
Many old wind turbine blades end up in piles at wind farms or landfills. In Europe, they’re sold to Latin American and Asian customers. Recycling companies and municipalities are now finding ways to break down the old blades to use as textiles for construction and manufacturing, or even use them as is in various public works projects.
Wind turbine blades last between 10 and 15 years, given the local conditions. They don’t last as long as the wind turbine itself and usually need to be replaced at least once during the lifespan of the turbine. Since they constantly rotate, they are subject to immense stress, and erosion from airborne particles.
The blades of a wind turbine are made of a composite material consisting of several layers of glass fabric and carbon fiber infused with plastic resin. This gives the blades the tensile strength it needs to withstand the immense forces and pressure of constant rotation.
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