A Louisiana company is turning decommissioned wind turbine blades into a low-carbon mixture for cement.
As wind energy expands, wind farms are swapping out decades-old turbine blades for newer models. The question has been what to do with those discarded blades, which most often end up in landfills. They are largely fiberglass — which contains silica, according to an article in the St. Louis Post-Dispatch.
Through the company, Veolia, the blades are run through shredders, gradually turning them into sawdust-like shavings. The components must reach a level of purity that’s suitable for them to be burned — because the next stop is a cement kiln. There, the ground-up material serves a dual purpose. The silica from the blades’ fiberglass strands becomes an essential ingredient in cement, while other components — including bits of wood — help fuel the kilns, which reach up to 3,000 degrees Fahrenheit.
According to the Post-Dispatch article, the cement industry has been an eager market, hungry for raw materials and energy, and increasingly aimed at reducing its substantial carbon footprint.
A Veolia spokesperson said that the availability of silica was the main thing to pique cement companies’ interest. As an added bonus, burning the rest of the cut-up blades provides enough energy to help kilns trim use of traditional fuels, such as coal. Using the material from the repurposed blades can decrease greenhouse gas emissions from cement production by 27%.
A recently signed four-year agreement with General Electric, a major supplier of wind turbine parts, likely provides sustainability to this project.