But when it’s time to shut one down, a wind turbine’s power may be weak. The blades are designed to be so durable that the materials used to build them cannot currently be recycled. By 2050, 43 million tons of these blades will be obsolete.
The new work describes a way to recover the main components of the wind turbine blades.
“We need sustainable energy, but we have to consider the waste and we have to find a solution for this,” said Alexander Ahrens, a postdoctoral researcher at the University of Aarhus in Denmark and the leader of the new study.
Wind turbine blades are made of a hard plastic called epoxy resin. Because of the chemical bonding that occurs when epoxy resin hardens, it cannot be melted and reshaped into a new shape, just like the plastic used in water bottles or milk jugs. In this case, the fibers are mixed into glue for added strength. This type of reinforced material – called fiberglass, when the support fiber is made of glass – is often used for high-strength applications such as airplane wings and boats.
“These materials are so durable that there is currently no suitable technology to recycle them,” says Ahrens.
There are some methods for breaking fiberglass, but these procedures usually render the epoxy part useless and often damage the fiberglass. The Aarhus researchers plan to devise an adequate mechanism to ensure that the main parts can be recycled.
The effect is that it locks the plastic into place and “focuses on chemical bonds that chew like Pac-Man – chew the epoxy and it frees those glass fibers,” says Trolls Skridstrup, professor of chemistry at Aarhus and co-author. The new study.
Researchers put epoxy materials in a liquid compound to break them down, which helped speed up the chemical reaction. They heated everything up to 160 degrees Celsius (320 degrees Fahrenheit) for 16 hours and several days until the target material was completely destroyed.