For his master thesis at Delft University of Technology, engineer Stijn Speksnijder aimed to find a new use for decommissioned wind turbine blades, by reusing them in a slow traffic bridge.

Wind energy is becoming a major source of renewable energy. Once a wind turbine is decommissioned after a use of 20-25 years, a large part of its materials can be recycled relatively easily. The blades, however, are often made of complex composite thermosetting materials, consisting of combinations of PVC foam, balsa wood, glass fibre and epoxy. These composites are hard to reuse and therefore often end up on the landfill or incineration plants, despite the fact that the high performance materials often still have excellent mechanical and chemical qualities.

One current solution for the waste is to shred the blades, but this generally results in the loss of material qualities.

Speksnijder’s project, dubbed Bridge of Blades, involves using the wind turbine blades in its entirety. Two clearly visible and recognisable blades cross the entire bridge and carry the bridge’s superstructure. The blades are rotated 180 degrees in respect to each other, creating a symmetrical design that evenly distributes the stress. Between the blades, a deck is placed for slow traffic like cyclists and pedestrians.

“The concept was developed regarding aesthetics, user interaction and structural performance,” Speksnijder says. “The resulting design is playful, dynamic and tells the story of how high performance materials can be re-used in a commercially viable solution. All components and connections were developed into detail with production and re-use of materials in mind.”

Images: Stijn Speksnijder