compared to coal, oil and gas, wind power proposes a cleaner form of energy generation. but how clean is it if the infrastructure cannot be repurposed or recycled? this is where researchers at the national renewable energy laboratory (NREL) come in. the US-based team led by senior wind technology engineer derek berry has 3D printed a 13-meter long wind turbine blade from thermoplastics to enable end-of-life recyclability and improve cost-effectiveness. 


‘today, most utility-scale wind turbine blades have the same clamshell design: two fiberglass blade skins are bonded together with adhesive and use one or several composite stiffening components called shear webs. this manufacturing process has been optimized for efficiency over the past 25 years — but, in reality, it has changed very little,’  explains NREL.

NREL makes wind power cleaner with recyclable turbine blades
image by ryan beach, NREL





to innovate the wind power industry, the researchers are focusing on the resin matrix material. current designs rely on thermoset resin systems like epoxies, polyesters, and vinyl esters, polymers that, once cured, cannot be remolded or reshaped.


‘once you produce a blade with a thermoset resin system, you cannot reverse the process,’  says derek berry. ‘that makes the blade difficult to recycle.’ 


unlike thermoset materials, thermoplastics can be heated to separate the original polymers, making them easier to recycle. thermoplastic blade parts can also be joined using a thermal welding process that could eliminate the need for adhesives, further enhancing blade recyclability.


‘with two thermoplastic blade components, you have the ability to bring them together and, through the application of heat and pressure, join them,’  continues berry. ‘you cannot do that with thermoset materials.’


the next step for NREL is to scale up the blades to well over 100 meters. 3D printing will help the team develop innovative blade core structures that are high-performing, relatively lightweight, and cost-effective to produce. if successful, NREL says they’ll be able to reduce blade weight and cost by 10% and production cycle time by at least 15%.


NREL is carrying out its research at its composites manufacturing education and technology (CoMET) facility. 




project info:


company: the national renewable energy laboratory (NREL)

project partners: TPI composites, additive engineering solutions, ingersoll machine tools, vanderbilt university, and the institute for advanced composites manufacturing innovation (IACMI)