December 9th, 2020 by

In November, we published a story from the Union of Concerned Scientists regarding the difficulty of recycling wind turbine blades. Those critical appendages have to be made super strong to withstand the rotational forces they are subjected to and the powerful winds they need to endure over their lifetime, which is typically 25 years. The UCS article pointed out how difficult even cutting then blades into smaller pieces can be.

“Cutting the extremely strong blades requires enormous equipment such as vehicle mounted wire saws or diamond-wire saws similar to what is used in quarries. Because there are so few options for recycling the blades currently, the vast majority of those that reach end-of-use are either being stored in various places or taken to landfills.”

The other factor to be considered today is repowering. It may seem like wind turbines are a relatively new phenomenon but some are already 20 years old. New turbines are much more powerful, with the latest Haliade-X machines from GE Renewable Energy rated at 13 MW. A typical rotor blade is 60 meters long. The Haliade-X blades are twice as long. Many of the mechanical components of older turbines can be reclaimed or recycled but the turbine blades cannot.

 

GE  Renewable Energy has found a new use for old turbine blades — chop them up and use them to make cement. In a press release, the company says it has signed a multi-year agreement with Veolia North America to recycle blades removed from its US-based onshore turbines during upgrades and repowering efforts. Veolia will use kiln reprocessing technology to turn the blades into raw material for cement. Similar recycling techniques have been proven effective at a commercial scale in Europe.

As a part of the agreement, blades that have been removed from turbines will be shredded at VNA’s processing facility in Missouri and then used as a replacement for coal, sand and clay at cement manufacturing facilities across the US. On average, nearly 90% of the blade material, by weight, will be reused as a repurposed engineered material for cement production. More than 65% of the blade weight replaces raw materials that would otherwise be added to the kiln to create the cement, and about 28% of the blade weight provides energy for the chemical reaction that takes place in the kiln.

According to Anne McEntee, CEO of GE Renewable Energy’s Digital Services business, “Sustainable disposal of composites such as wind turbine blades has been a challenge, not only for the wind turbine industry, but also for aerospace, maritime, automotive and construction industries. VNA’s unique offering provides the opportunity to scale up and deploy quickly in North America, with minimum disruption to customers and significant benefit to the environment. We look forward to working with them on this effort to create a circular economy for composite materials.”

Bob Cappadona, COO for VNA’s Environmental Solutions and Services division, adds “By adding wind turbine blades — which are primarily made of fiberglass — to replace raw materials for cement manufacturing, we are reducing the amount of coal, sand and minerals that are needed to produce the cement, ultimately resulting in greener cement that can be used for a variety of products. Last summer we completed a trial using a GE blade, and we were very happy with the results. This fall we have processed more than 100 blades so far, and our customers have been very pleased with the product. Wind turbine blade repurposing is another example of Veolia’s commitment to a circular economy and ecological transformation in which sustainability and economic growth go hand in hand.”

An environmental impact analysis conducted by Quantis U.S. found that the net effect of blade recycling through cement kiln co-processing is positive in all categories. Compared to traditional cement manufacturing, blade recycling enables a 27% net reduction in CO2 emissions from cement production and a 13% net reduced water consumption. In addition, material from a typical 7 ton wind turbine blade avoids the consumption of nearly 5 tons of coal, 2.7 tons of silica, 1.9 tons of limestone, and nearly a ton of additional mineral-based raw materials.

Largely due to the avoided coal consumption, this type of blade recycling also has a net-positive environmental impact in the categories of human health, ecosystem quality, and resource consumption. The resulting cement has the same properties and performance as cement manufactured using traditional means, meeting all applicable ASTM standards.

GE Renewable Energy has devised a plan to decarbonize its operations and achieve carbon neutrality by the end of this year. Its various business ventures frequently partner with other companies to drive innovation for improved sustainability. Recently in the news, there have been several stories suggesting the wind industry needs to do more to keep old turbine blades out of landfills, so this announcement from GE Renewable Energy is welcome news indeed.