A new material for wind blades that can be recycled could transform the wind industry, rendering renewable energy more sustainable than ever before while lowering costs in the process.

The use of a thermoplastic resin has been validated at the National Renewable Energy Laboratory (NREL). Researchers demonstrated the feasibility of thermoplastic resin by manufacturing a 9-meter-long wind turbine blade using this novel resin, which was developed by a Pennsylvania company called Arkema Inc. Researchers have now validated the structural integrity of a 13-meter-long thermoplastic composite blade, also manufactured at NREL.

In addition to the recyclability aspect, thermoplastic resin can enable longer, lighter-weight, and lower-cost blades. Manufacturing blades using current thermoset resin systems requires more energy and manpower in the manufacturing facility, and the end product often winds up in landfills.

“With thermoset resin systems, it’s almost like when you fry an egg. You can’t reverse that,” said Derek Berry, a senior engineer at NREL. “But with a thermoplastic resin system, you can make a blade out of it. You heat it to a certain temperature, and it melts back down. You can get the liquid resin back and reuse that.”

Berry is co-author of a new paper titled, “Structural Comparison of a Thermoplastic Composite Wind Turbine Blade and a Thermoset Composite Wind Turbine Blade,” which appears in the journal Renewable Energy.

The other authors, also from NREL, are Robynne Murray, Ryan Beach, David Barnes, David Snowberg, Samantha Rooney, Mike Jenks, Bill Gage, Troy Boro, Sara Wallen, and Scott Hughes.

NREL has also developed a technoeconomic model to explore the cost benefits of using a thermoplastic resin in blades. Current wind turbine blades are made primarily of composite materials such as fiberglass infused with a thermoset resin. With an epoxy thermoset resin, the manufacturing process requires the use of additional heat to cure the resin, which adds to the cost and cycle time of the blades. Thermoplastic resin, however, cures at room temperature. The process does not require as much labor, which accounts for about 40% of the cost of a blade. The new process, the researchers determined, could make blades about 5% less expensive to make.

KeyFacts Energy Industry Directory: NREL