DOE working on new, recyclable material for wind turbine blades

Researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), working with Arkema, are developing a new material for wind blades that can be recycled.

This breakthrough research could transform the wind industry, making renewable energy more sustainable while lowering costs in the process.

Blades are currently manufactured using thermoset resin, which requires more energy and manpower to make. Plus, the used end product often ends up in landfills. The researchers have found a new material, thermoplastic resin, and validated its structural integrity on a thermoplastic composite blade manufactured at NREL.

Switching to thermoplastic resin would make wind turbine blades more recyclable. They would also be longer, lighter-weight, and cost less than current blades.

“With thermoset resin systems, it’s almost like when you fry an egg. You can’t reverse that,” Derek Berry, a senior engineer at NREL, said. “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 co-authored a paper on the subject called “Structural Comparison of a Thermoplastic Composite Wind Turbine Blade and a Thermoset Composite Wind Turbine Blade.” It appears in the journal Renewable Energy.

Also, NREL has developed a technoeconomic model to explore the cost benefits of using a thermoplastic resin in blades. Thermoplastic resin cures at room temperature, and the process does not require as much labor. The new process could make blades about 5 percent less expensive to make, the researchers said.

“The thermoplastic material absorbs more energy from loads on the blades due to the wind, which can reduce the wear and tear from these loads to the rest of the turbine system, which is a good thing,” Robynne Murray, co-author of the paper, said.