RobWind: Robot-based material recovery for wind turbine rotor blades

At a glance

• Rotor blades consist of a complex structure made of various materials, which has so far made the disassembly required for efficient recycling difficult.
• The research project RobWind combines two systems to enable material-specific disassembly of the blades near the wind turbine: a mobile measurement platform for analyzing the rotor blade structure and a mobile waterjet cutting robot.
• Among other things, Fraunhofer IWES is responsible for the further development and testing of the measurement platform and the associated actuators and sensors on the rotor blade.

The challenge

Given the aging wind turbine infrastructure, the recycling of rotor blades is becoming increasingly important. These components consist of specifically arranged materials such as glass fibers, carbon fibers, balsa wood, foams, and other materials. Efficient recycling requires the precise separation of these materials; the more precise the separation, the higher the potential recycling rate. Currently, wind farm operators are mostly unaware of the exact locations of the individual materials within the rotor blade, which significantly complicates recycling-oriented disassembly. As a result, decommissioned rotor blades are primarily cut mechanically on-site into six-meter-long parts, then shredded and used for energy recovery.

The solution

This is where the RobWind research project comes in. The goal is to enable material-specific disassembly in the field by further developing and combining two different systems that are currently under development.

First, material transitions in the rotor blade, on the turbine itself or on the ground after disassembly, are recorded using a semi-automated, unmanned mobile measurement platform. AI-supported image analysis of active thermography data is used to identify and locate the individual material components. A novel aspect of this approach is the use of active thermography directly in the field during the wind turbine’s dismantling to optimize the disassembly processes for material-specific recycling.

Based on this, the next step involves identifying the ideal cutting points for disassembling the rotor blade. The disassembly is performed using a mobile waterjet cutting robot on the ground, directly next to the wind turbine. The robot automatically plans its route based on the previously detected and localized material transitions.

The added value

RobWind uses an innovative approach to significantly increase the efficiency of rotor blade recycling. This makes it possible to overcome the challenges associated with separating fiber-reinforced composites. As a result, it makes a significant contribution to the industry’s goal of building a completely CO₂-free wind turbine. At the same time, valuable raw materials can be reused and waste can be avoided.