National Renewable Energy Laboratory (NREL) scientists have developed a new recyclable, wind turbine material that could make the wind industry even more sustainable than it already is.
The NREL team along with Pennsylvania-based Arkema Inc. have demonstrated the feasibility of this new thermoplastic resin and validated its structural integrity on a thermoplastic composite blade manufactured at NREL.
Unlike the regular thermoset resin used for manufacturing wind turbine blades, thermoplastic resin could make wind turbine blades longer, lighter-weight, low-cost, and above all, recyclable.
“With thermoset resin systems, it’s almost like when you fry an egg. You can’t reverse that,” says NREL senior engineer Derek Berry.
“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.”
The NREL team has also developed a techno-economic model to explore the cost benefits of using a thermoplastic resin in blades.
According to the scientists, 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 additional heat to cure the resin, which adds to the cost and time to manufacture blades.
Thermoplastic resin on the other hand cures at room temperature. The process does not require as much labor, which currently accounts for about 40% of the cost of a blade.
According to co-author Robynne Murray, the new material absorbs more energy from loads on the blades due to the wind. This reduces the wear and tear from these loads to the rest of the turbine system.
The thermoplastic resin could also allow manufactures to build blades on site – paving the way for larger and longer blades that currently require painstaking transportation from a manufacturing facility.
Image and content: Dennis Schroeder/NREL