THERMO-BLADE-SPINE

Project Description

The THERMO-BLADE-SPINE project develops technological building blocks for efficient, high‑rate and circular manufacturing processes of rotor blades made from recyclable thermoplastic composites (TPC). This approach is based on the CONTIjoin process developed at Fraunhofer IWS, which enables the automated manufacturing of main spars through layup of pre-produced composite material straps. In addition, the use of novel TPC and sandwich components (Fraunhofer IMWS), along with corresponding design concepts, aims to replace energy‑intensive process steps. Fraunhofer IWES coordinates the overall project, contributing its expertise in the production of research rotor blades as well as material and component testing. It is also responsible for designing and implementing the manufacturing process of an 18‑meter demonstrator at the BladeMaker DemoCenter. To support future certification, systematic coupon tests are being designed and conducted to validate the performance of the developed technological building blocks.

Motivation

Today’s manufacturing of wind turbine rotor blades relies heavily on manual labor, making it cost-intensive, error-prone, and subject to significant cost pressure. Manufacturers are increasingly shifting production to low-wage countries, while growing blade dimensions simultaneously raise requirements for quality and reliability – intensifying the risks associated with manual processes. Another pressing challenge concerns end-of-life management: thermoset resins, used since the 1980s, cannot be melted or dissolved, making material separation and recycling of fiber-reinforced polymer (FRP) rotor blades nearly impossible. As a result, industry lacks both recyclable materials and robust, automatable manufacturing methods. Previous approaches have failed due to high costs and complex handling. Against this backdrop, circular, automated production methods that address quality, cost efficiency, and sustainability in equal measure are urgently needed. The THERMO-BLADE-SPINE project addresses these challenges by developing innovative manufacturing processes for thermoplastic composite rotor blades. These technologies enable efficient, scalable production processes as well as a true cradle-to-cradle approach for end-of-life rotor blades. With the growing market share of thermoplastic composites in Europe, the technologies developed in this project offer significant industrial application potential, supporting an accelerated and sustainable expansion of wind energy.

Objectives and Approach

THERMO-BLADE-SPINE aims to develop and scale up automated, high‑rate manufacturing processes based on thermoplastic composites to enable circular rotor blade production. At the core of the approach is the automated construction of the main spars using the CONTIjoin process and pre‑fabricated TPC straps. This is complemented by the integration of novel TPC and sandwich components, along with corresponding structural concepts, to replace energy‑intensive process steps. At the BladeMaker Center of the Fraunhofer Institute for Wind Energy Systems (IWES) in Bremerhaven, the CONTIjoin technology will be scaled up on a several meters long test rig. The goal is to demonstrate the suitability of the process as an innovative approach for manufacturing large-scale main spars within an 18‑meter tool with complex curvature. In parallel, Fraunhofer IWES designs and implements the demonstrator blade production in the BladeMaker DemoCenter, conducts material and component testing, and prepares certification through systematic coupon testing. This ensures that processes, materials, and structures are validated under realistic conditions – paving the way toward industrial adoption. Ultimately, THERMO-BLADE-SPINE aims to demonstrate that highly automated rotor blade manufacturing can be both cost‑efficient and sustainable even in high-wage countries. The project therefore contributes to the development of zero‑waste wind turbines and helps reduce Germany’s dependency on international supply chains within a strategically important industry.

Innovation and Outlook 

Thermoplastic composites combine excellent mechanical performance with compatibility for automated processing and, due to their meltability, enable material recycling – making them ideal for high‑rate and sustainable rotor blade production. The continuous joining process CONTIjoin enables a reproducible and automated build‑up of main spars and plays a key role in achieving high process throughput. By delivering a technology demonstrator, the project will validate that automated rotor blade production can be both economically and ecologically viable in high-wage regions. In the long term, the project makes a substantial contribution toward zero‑waste wind energy systems and reduces Germany’s dependence on international supply chains in a strategically critical industrial sector.