Wind energy has soared in popularity in the last couple of decades. Today, 8.4% of the total electrical energy produced in the United States comes from wind power. With so many utility-scale wind turbines being installed, it is critical to consider the sustainability of the wind energy industry. That includes what happens to the wind turbines when they are decommissioned.
Wind turbines are made mainly of metal and can readily be recycled into high-value goods. However, the wind turbine blades are an exception. As a result, many wind turbine blades end up in landfills or are incinerated because they are costly to recycle. Unfortunately, the scale of this issue will increase dramatically worldwide as wind farms reach the end of their lifespan.
Are there opportunities to repurpose wind turbine blades that create greater value to nearby communities? The Re-Wind Network is exploring that very question. It is a collaboration between researchers in the United States, Ireland, and Northern Ireland studying repurposing options for wind turbine blades in a variety of civil engineering projects.
Repurposing Wind Turbine Blades
Re-Wind’s fall 2021 design catalog contains a wide variety of footbridges, as well as poles for electrical distribution and transmission lines, cell phone towers, street lights, and signs. In addition, it features noise barriers for highways, bus shelters, glamping pods, and agricultural applications, such as cattle partitions and feed bunks.
“We’re exploring the potential reuse of the blades across architecture and engineering,” said Larry Bank, a member of the Re-Wind team.“Developing such methods can have a positive effect on air quality and water quality by decreasing a major source of non-biodegradable waste.”
Although the design life of a wind turbine is about 20 to 30 years, the turbine blades are very durable and have a hollow core. In fact, they can be used for bridges that can last more than a century.
Sample Turbine Blade Projects
There are numerous successful examples of repurposing wind turbine blades for playgrounds in the Netherlands, bike shelters in Denmark, and stylish garden and street furniture. For example, the first pedestrian bridge was recently installed in western Poland after a battery of engineering tests. In County Cork, Ireland, wind turbine blades are used to make pedestrian bridges in a new greenway project.
Other Possible Repurposing Options
Further research is needed to test and standardize the use of wind turbine blades in a variety of useful applications. The Re-Wind team is even examining the use of turbine blades for building affordable housing, especially for durable roofing materials.
“One of the first things we looked at was cutting up these blades into pieces that could be given for free or for very low cost to individuals in economically deprived neighborhoods that could be using them for construction,” said Bank, This is particularly appealing in areas prone to extreme weather, yet blades were designed to withstand the elements.
Streamlining the Repurposing Process
To promote the reuse of blades, it is critical to make it simple and cost-effective. The Re-Wind team is working on streamlining and standardizing the design process to make it more economical and swift. Testing certain blades for specific applications mitigates the engineering challenge of repurposing blades.
Why Not Recycle the Blades Instead of Repurposing Them?
Turbine blades are difficult to recycle into high-value goods because they are made of fiberglass and composite materials. As a result, recycling often involves downcycling the material into low-value building products. This approach isn’t usually economically viable though; it often has a higher cost than just disposing of the blades.
Although it can be challenging to repurpose wind turbine blades on a large scale, it offers many advantages over recycling. Repurposing can save energy compared to recycling, which can be an energy-intensive process.
Ultimately, transitioning to truly recyclable materials will eventually decrease the need to repurpose blades, especially as developers decommission more wind farms. Researchers at the National Renewable Energy Laboratory (NREL) have developed a lightweight blade from thermoplastic resin that seems to be recyclable. Further research is needed, but NREL seems to be making progress.
Editor’s note: An earlier version of this article said wind generation was the source of 8.4% of the energy consumed in the United States. The correct statement is that wind is the source of 8.4% of electricity produced annually in the U.S.