What to do with wind turbine blades? by Ben Jackson

Transitions for Sustainability Vol 1 No 10

Introduction

The energy transition is coming; significant capital is being allocated to build out renewable energy. In 2022 alone $12 billion was assigned to building out wind power.

Wind turbine blades are made from composite materials, such as fiberglass and carbon fiber. But, they only have a limited life span of 20 years. Around 96% of wind turbines by weight are able to be recycled or repurposed when decommissioned but currently the blades of the turbine are not able to be.  These blades can be up to 108 meters (354 feet) in length, and are only growing with the average length increasing by 20% since 2009.  Wind turbine blades once decommissioned have been used in a few different ways on a small scale such as, bike sheds in Denmark, noise barriers on highways in the US, and glamping pods at festivals. This is only viable on a limited scale. What do we do with this waste when in ~ 20 years, the largest plant in the world Hornsea 2 and its 165 turbines become decommissioned?

What are composites?

Composite materials have been long used in construction, to combine properties of multiple materials to create a superior one. It is not a new concept. Modern composites (FRP’s) are relatively recent inventions, with fiberglass being launched in 1935 and carbon fiber patented in 1961 respectively. Once invented they forced the redesign of many existing products, particularly in high performance scenarios, such as race cars and bicycles.

FRP’s combine resin and fibers, such as glass or carbon together. Without the resin, the fibers are extremely strong in tension but provide little to no resistance to compression. Whereas resin is extremely strong in compression but is significantly weaker in tension. Once you combine both materials you are left with a lightweight material that is resistant to both compression and tension. 

Why are composites used in wind turbines?

FRPs are used in the construction of wind turbines, due to the properties that were previously discussed. The materials are lightweight, strong, and can be easily formed into a mold. Allowing them to be formed to extremely large molds, whilst at the same time following intricate designs for optimal aerodynamics, all with minimal finishing required. Additionally, FRPs are also inert, which makes them perfect for offshore environments. They are resistant to corrosion promoting the longevity of the blades, whilst also posing no risk of environmental contamination if something were to go wrong,

What is the problem?

Renewable energy is the future of energy in the world. To make the transition over the next few decades there is going to be a rapid deployment of many products, including wind turbines, on a large scale. However, like any product, turbines have a limited life span. Whilst we are utilizing wind turbines to address issues with emissions tied to our energy supply and our reliance on non-renewable resources, there is currently no model for what to do with wind turbine blades after they finish their lifetime of service. Currently, these large plastic products are disposed of within landfill, or incinerated. Between 2029 - 2033 it is predicted that annually 400,000 tonnes of blades will be decommissioned annually, this is expected to rise to 800,000 by 2050. To not have a sustainable solution to decommissioned products that are supposed to have positive impacts, is very short sighted and if not corrected for has the potential to be extremely problematic, as the waste is only going to pile up.

Company Commitments

Many leading wind turbine companies have made commitments surrounding the recycling or repurposing of their products; however, they still acknowledge that the blades continue to pose a challenge for them to overcome, as currently they are just put into landfill. Orsted has made commitments to recycle the blades, but as there is currently no viable option, they will be temporarily storing the blades.

Beyond these commitments that have been made it should be acknowledged that the structure of these projects often means that over the lifespan there might be many different owners, this poses a challenge for the accountability in meeting these goals. After the 20 years of the operational cycle, it is likely that the management of the company will change, the operational status of the company may change, or another issue emerges that makes these commitments potentially hard to enforce. Therefore, it is imperative that there is a commercially viable solution, one that does not generate major costs at the end of the lifecycle of the turbine for the blades. If the cheapest, easiest option is to landfill the blades then if the commitments fall through, the blades will likely end up in landfill and we will not have addressed the issue. Therefore, a product or scheme to repurpose or recycle the blades needs to be developed so that there is an easy, cheap option to repurpose or reuse the blades.

What can be done?

The most environmental choice that can be made after a product has served its purpose, is to reuse it in another way. The most polluting stage of the lifecycle of a product is its initial production. Therefore, when looking to address the problem, it would be best if there was a commercially viable product that the retired blades could be transformed into. To be able to reuse or recycle them, the impact of the blades on the environment would be significantly reduced and confirm their position as the alternative to fossil fuels.

To find a product to repurpose the wind turbines into, you first need to consider what properties the retired blades are left with after they have been decommissioned. The key property that the turbine blades would still hold even after serving a full life cycle would be their waterproofness. This would not be compromised after serving a full lifecycle as the material naturally holds this property.

However, the properties that work against turbine blades being repurposed are many. Hence, currently a viable option to reuse the majority of blades has not been found. FRPs once initially cast into the molds and cured, cannot be changed, therefore any product that the blade is repurposed for would be constrained by the dimensions and shape of the blades. This potentially poses the biggest challenge to overcome. In order to repurpose a blade, you need to find a product that lends itself to the dimensions and shape of the wind turbine blade.

Below there are potential projects that could utilize decommissioned wind turbine blades, that have the potential to generate not only environmental good through diverting the blades away from landfill but additional benefits that could be assigned a monetary value. Through repurposing the blades into projects that could create a substantial benefit the blades could generate returns. Thereby creating a price for the decommissioned blades, which encourages companies to pursue these options rather than sending the blades to landfill or keep in storage for an undetermined time frame.

Affordable Housing

On any given night in 2022, 582,500 people were experiencing homelessness in the United States. Four out of ten of those people were experiencing homelessness without shelter. The key property that wind turbines hold beyond their lifecycle is their waterproofness. These waterproof large structures are currently being disposed of but easily could be converted to provide shelter to those who need it most.

Recently, California committed to spending $30 million building 1,200 tiny homes in their state to provide shelter to the homeless. Beyond the social benefit of reducing homelessness in the population there is an economic benefit too. Housing the homeless has been shown to generate serious economic value. In California it was found that an unhoused person in Silicon Valley who made significant use of public services cost just under $62,500 annually, whereas one who is provided housing in the same area costs the state under $20,000. This $42,500 saving just from providing shelter can be broken down into a number of different factors. By providing shelter the state can reduce the money spent on police interactions with the homeless annually, which was estimated to be between $53.6 million and $87.3 million in Los Angeles alone, additionally they would be able to reduce the $547,000 spent by the Bureau of Sanitation annually to cleanup encampments. Unsheltered homelessness can have physical impacts on the community also, in December 2017 the Skirball Fire, burned more than 400 acres, 6 homes and damaged 12 homes in Bel-Air was attributed to open-fire cooking in an homeless encampment. Therefore, there are clear monetary benefits to providing shelter for the homeless. This presents the opportunity for a scheme that can be investable. There are clear returns to be unlocked for the state, if there was investment into housing the homeless.

Wind Turbine blades could be used as the roofing for those houses. The blades have already been manufactured, they are waterproof and could be cut easily to fit onto the housing. The homes are as small as 120 sq feet. This small format of the tiny homes would enable the blades to easily provide roofing for the homes with limited modifications. This utilization of the blades for this application would in turn create a buyer for them. Tiny homes are utilized in many scenarios to provide emergency housing to the unsheltered or in emergency scenarios, if they utilized the blades as roofing on the homes, a buyer for decommissioned blades would be created.

Currently, wind turbine companies must pay for decommission of their turbines which include the costs associated with landfilling their blades. By creating a company that takes these blades and repurposes them to be a part of a small house for the homeless, these companies would be able to save money as they would not have to pay the landfill costs. Making this an attractive option for them both socially and economically. Companies utilizing the blades in their products potentially could even charge the companies the price that they would have paid the landfill, due to the benefit that they would be providing them. This use would allow wind companies to not only have their blades repurposed, decreasing their products impact on the environment, but would also enable them to extract extra social value from the product through the creation of housing and aiding in the building of a platform to relaunch people back into society which can benefit them in regards to their own ESG plans.

Urban Heat Island Effect; Parking Garages

The urban heat island effect is responsible for between 1–7°F degrees of warming during the day locally, when compared to outlying areas. The Heat Island effect as defined by the EPA as “urbanized areas that experience higher temperatures than outlying areas”. The features of a Heat Island include structures that absorb and re-emit the sun’s heat more than natural landscapes. Unshaded parking lots have the ability to become “mini-urban heat islands” that contribute negatively to human health.

Building off the idea of Wind Turbine blades being refashioned as roofing; they could be refashioned as a sunshade that is installed over parking garages. Wind turbine blades generally are white. White objects have an albedo close to 1, whereas black objects have an albedo close to 0.  Albedo is the fraction of light that is reflected by an object. Therefore, white objects will reflect the majority of the light. By placing white wind turbine blades over parking lots, the albedo of the area can shift from being close to 0 to being close to 1, this stark change will eliminate the urban heat island effect of the parking garage and even contribute to cooling of the area.

Therefore, there is an opportunity to repurpose the blades into a product to further reduce global warming. This too can assign value to the decommissioned blades as it creates real benefit for society, through reducing the heat island effect of parking garages. Again, this would create an option for the operators of wind turbines to reduce their costs from decommissioning their blades, as they would not have to pay the fees associated with putting the blades into landfill. The purchasers of the blades would reduce their material costs, potentially getting paid to take the blades off the operator’s hands and repurpose them. Then they can then extend their lifespan by installing them over parking garages, providing shelter, and reducing the heating effect of parking garages.

Recycling

The next best alternative to repurposing the wind turbine blades is to recycle them. However, there is currently no established process to do this. But it would be inappropriate to not acknowledge the few offerings that potentially might make this option feasible.

Recently, Carbon Rivers has been able to discover a potentially commercially viable technology that can upcycle the components that make up a wind turbine blade. This is incredibly exciting because it is another technology that will reduce the number of turbine blades going to landfill annually. The planned facility is expected to be able to process 50,000 metric tons of turbine blades every year. As stated before annual waste from turbine blades is expected to be 400,000 by some point between 2029 - 2033 and is expected to grow. So although this technology is incredibly exciting and in the long term after being scaled has the potential to be a part of the solution in its current form it can only be used as another tool to deal with the blades.

Another technology developed by Veolia North America, that is in its infancy, is shredding the blades and transforming them into raw materials to be used in cement. Through using the blades in cement they are able to reduce the carbon dioxide emissions by 27% and the water usage by 13%. However, even through this process they are unable to recycle 100% of the blade. Veolia has been able to recycle 2,000 blades in two years. Therefore, the process to turn them to cement is one that certainly will contribute to the decommissioning of the blades, but currently cannot take the whole load.

There are also controversies associated even with the proven recycling technologies. Global Fiberglass Solutions (GFS) founded in 2009. Recently, was sued by General Electric (GE) due to GFS stockpiling the blades that GE had paid a premium to have them recycled. GE had paid nearly $17 million to recycle their blades however GFS had been stockpiling the blades as they needed additional funds to complete the infrastructure to pelletize the blades. This lawsuit highlights that recycling the blades is neither a cheap service nor an abnormally profitable business. GFS was paid nearly $17 million to recycle 5,000 blades. Yet, even with this price point chose to stockpile the blades instead.

For blades to be processed there needs to be ample incentive for both the wind turbine companies and those who are contracted to recycle the blades. Without that the blades will continue to be kept in storage or ultimately sent to landfill. Additionally, many of the new generation turbine blades produced contain carbon fiber. Currently there is no method to recycle the carbon fiber in the blades, only the glass fibers, so when the generation currently in use is decommissioned, this poses a threat to the recyclability of the blades.

Conclusion

Wind turbines are going to be an integral part of making the switch to renewable energy, because of the transition there are going to be many decommissioned turbine blades. These blades currently are the one part of the turbine preventing it from fully being aligned with its sustainable mission.

In order to make sure that the blades are reused the opportunities for businesses to utilize these decommissioned blades as materials need to be realized. For these businesses the same properties that make the blades difficult to recycle can make them extremely useful. By repurposing the blades there is an opportunity for them to continue to create benefits beyond their designed lifespan, either through established schemes such as bike racks, and noise barriers, or through new innovative schemes addressing issues such as homelessness and the urban heat island effect. Through repurposing the blades into products that hold benefit, wind turbine companies can extend the benefits of their products, and a price is able to be allocated to the decommissioned blades. As the companies utilizing the blades would create a market for them. If enough of these projects that use decommissioned blades can be created a significant portion can be repurposed, preventing them going to landfill. Whilst extending their lifetime, and creating additional social and environmental good.

The priority should be to repurpose the blades, as that is the most environmentally friendly use of them, but recycling the blades is the next best option. Currently, the offerings for recycling the blades do not have the ability to recycle all of them. Additionally, the industry appears to have issues being financially viable. Once technologies mature, recycling the blades that are not repurposed is the next best option, as it addresses the core issue of preventing these blades from going to landfill.

Sources Used

Andersen, P. D., Bonou, A., Beauson, J., & Brøndsted, P. (2014). Recycling of wind turbines. In H. Hvidtfeldt Larsen, & L. Sønderberg Petersen (Eds.), DTU International Energy Report 2014: Wind energy — drivers and barriers for higher shares of wind in the global power generation mix (pp. 91-97). Technical University of Denmark. 

Bralower, T., & Bice, D. (n.d.). Albedo. PSU. Retrieved November 5, 2023, from https://www.e-education.psu.edu/earth103/node/1002

California State Auditor. (2018, April). Report 2017-112. California State Auditor. Retrieved November 5, 2023, from https://www.auditor.ca.gov/reports/2017-112/chapters.html

Chang, B. (2023, October 18). First of California's $30 Million Tiny Homes to Open in Sacramento: Photos. Business Insider. Retrieved November 5, 2023, from https://www.businessinsider.com/california-spend-30-million-build-1200-tiny-homes-photos-2023-3#los-angeles-will-receive-the-most-at-500-units-while-san-diego-will-be-dealt-the-least-with-150-tiny-homes-4

Cotrone, V. (2022, August 11). Green Parking Lots: Mitigating Climate Change and the Urban Heat Island. Penn State Extension. Retrieved November 5, 2023, from https://extension.psu.edu/green-parking-lots-mitigating-climate-change-and-the-urban-heat-island

Department of Energy. (2022, October 17). Carbon Rivers Makes Wind Turbine Blade Recycling and Upcycling a Reality With Support From DOE. Department of Energy. Retrieved November 5, 2023, from https://www.energy.gov/eere/wind/articles/carbon-rivers-makes-wind-turbine-blade-recycling-and-upcycling-reality-support

Department of Energy. (2023, August 24). U.S. Department of Energy Projects Strong Growth in U.S. Wind Power Sector. Department of Energy. Retrieved November 5, 2023, from https://www.energy.gov/articles/us-department-energy-projects-strong-growth-us-wind-power-sector

EPA. (2023, August 28). Learn About Heat Islands | US EPA. EPA. Retrieved November 5, 2023, from https://www.epa.gov/heatislands/learn-about-heat-islands

HUD. (2022, December). The 2022 Annual Homelessness Assessment Report (AHAR to Congress) Part 1: Point-In-Time Estimates of Homelessness, December 2022. HUD User. Retrieved November 5, 2023, from https://www.huduser.gov/portal/sites/default/files/pdf/2022-AHAR-Part-1.pdf

Jacoby, M. (2022, August 8). How can companies recycle wind turbine blades? C&EN. Retrieved November 5, 2023, from https://cen.acs.org/environment/recycling/companies-recycle-wind-turbine-blades/100/i27#

Johnson, B. (2023, September 27). General Electric Sues Texas Recycling Company Responsible for Sweetwater Wind Turbine Blade Dump. The Texan News. Retrieved November 5, 2023, from https://thetexan.news/issues/energy/general-electric-sues-texas-recycling-company-responsible-for-sweetwater-wind-turbine-blade-dump/article_1679ce30-5c89-11ee-a6a3-9f11a95ab89d.html

National Grid. (2023, April 28). Can wind turbine blades be recycled? | What happens to old wind turbine blades? National Grid. Retrieved November 5, 2023, from https://www.nationalgrid.com/stories/energy-explained/can-wind-turbine-blades-be-recycled

NGUYỄN, T. (2023, October 11). After delays, California unveils first site of state tiny home project to relieve homelessness. AP News. Retrieved November 5, 2023, from https://apnews.com/article/california-governor-gavin-newsom-tiny-homes-4ff201e339631cfb6190c78a5014774e

Orsted. (n.d.). Hornsea Two offshore wind farm. Hornsea Projects. Retrieved November 5, 2023, from https://hornseaprojects.co.uk/hornsea-project-two

Orsted. (2021, June 2). Ørsted commits to sustainable recycling of wind turbine blades. Orsted. Retrieved November 5, 2023, from https://orsted.com/en/media/newsroom/news/2021/06/702084352457649

Phillips, A. (2022, February 16). How Long are Wind Turbine Blades? Energy Follower. Retrieved November 5, 2023, from https://energyfollower.com/how-long-are-wind-turbine-blades/

Proops, J. L. R., Gay, P. W., Speck, S., & Schröder, T. (1996). The lifetime pollution implications of various types of electricity generation. Energy Policy, 24(3), 229-237. https://www.sciencedirect.com/science/article/pii/0301421595001549?via%3Dihub

Wood, K. (2012, May 31). Wind turbine blades: Glass vs. carbon fiber. Composites World. Retrieved November 5, 2023, from https://www.compositesworld.com/articles/wind-turbine-blades-glass-vs-carbon-fiber