Renewable energies

Manufacturing technologies

Wind energy is one of the cheapest sources of energy today. This is also a success of manufacturing technology, whose advances now allow modern wind turbines to be produced and erected efficiently. Fraunhofer IFAM is continuously improving manufacturing technologies to make wind power even more efficient, sustainable and cost-effective. Our areas of focus include

Automation of generator production: 

By automating this critical process, we reduce tolerances and thus increase the efficiency of the generators. This leads to greater reliability and lower production costs.

Electric drives:

Our expertise in the design of electric drives focuses on creating efficient and robust systems that are adapted to the demanding conditions of wind energy applications. These electric drives are critical to the smooth operation and longevity of wind turbines and contribute to overall energy efficiency and cost effectiveness.

Adhesive Bonding Technology:

We develop advanced adhesive bonding solutions that are designed to meet the high demands of the wind energy industry. Our bonding technologies ensure strong and durable bonds, extending the life of rotor blades and other critical areas such as grout joints.

Bonding the blade shells is not only important from a structural-mechanical point of view, but is also a very relevant step in the production of rotor blades. In addition to fast and needs-based application of the adhesive, reliable curing is essential for efficient production. In order to develop optimal solutions for these challenges, Fraunhofer IFAM is working on adhesive application as well as process-integrated quality assurance and digitalization in addition to structural mechanical evaluation methods and adhesive evaluation.

Adhesive bonding technology is also becoming increasingly important in heavy steel construction as, unlike welding, it does not change the basic material properties of the metal parts to be joined. When joining foundation structures, adhesive bonding can therefore be used to enable connections and reinforcements without reducing the load-bearing capacity of the main pipes and nodes. Such bonding is also possible under water and in the splash zone.

Grout connections are often used in the offshore wind energy sector to connect the foundation structure to the tower. Special adhesives based on concrete or cement are typically used here. In order to achieve good load transfer and high fatigue strength of the joints, the Fraunhofer IFAM is working on multilayer grout joints, among other things. In these, thin layers of structural adhesives ensure adhesion to the surfaces of the parts to be joined and protect the steel surfaces from corrosion.

Innovative fiber composites:

Modern wind turbines would be inconceivable without fiber composites. Thanks to their excellent weight-specific properties and freedom of design, they enable the production of aerodynamically efficient, lightweight and ever longer rotor blades.

Current challenges in the rotor blade industry include recycling, the resilient coverage of European and national demand and the reliability of rotor blades in the field. These issues are closely linked to the materials used, the processes and quality management. 

The institute's activities in the field of fiber composites include the development of bio-based and recyclable resin systems to improve the sustainability of rotor blade production.  The innovative PeelPlas system enables the release agent-free and therefore more efficient production of rotor blades. The Fraunhofer IFAM also runs a training center for fiber composites to train specialists in this field and strengthen know-how in the industry. In addition, damage and root cause analyses are carried out to identify manufacturing imperfections or field damage and to develop solutions for their elimination.

Release agent-free production of rotor blades: 

Conventional liquid mold release agents ensure that components made of plastics or fiber-reinforced plastics (FRP) can be demolded after curing. The process is tried and tested, but has many disadvantages: for subsequent processes such as bonding and painting, residues of the mold release agent must be laboriously and time-consuming removed from the component surfaces to ensure sufficient adhesion. In addition, release agent residues also remain on the mold, which must be removed regularly. This is why scientists at Fraunhofer IFAM have developed the thermoformable release film PeelPLAS®, which replaces liquid release agents and thus enables release agent-free plastics production for the first time and avoids sanding dust contamination before coating processes.

Surface technology

Our research work in surface technology lays the foundation for high-performance and durable wind turbines. We develop state-of-the-art coatings that are specially designed for the extreme conditions to which wind turbines are exposed. These include

Erosion protection for rotor blades:

Rotor blades of wind turbines are exposed to enormous erosion stresses. In addition, the blade surfaces are attacked by weathering, e.g. UV radiation, humidity, temperature changes, salty spray, but also particle erosion by sand. The Fraunhofer IFAM is working on erosion-resistant, weather-resistant and application-oriented systems based on paint or semi-finished products in order to achieve high erosion resistance during operation. In addition, the institute is developing test methods to ensure the durability of erosion protection coatings.

Self-healing coatings:

We develop coating systems that are able to repair minor damage on their own, thus reducing the need for maintenance.

Artificial ageing:

Our research also includes the artificial ageing of coatings. By simulating real and accelerated ageing processes, we can evaluate and improve the long-term performance of our protection systems to ensure that they remain effective throughout the entire service life of the wind turbines.

Anti-ice coatings:

Together with our partners, we develop materials that prevent the formation of ice on rotor blades, ensuring aerodynamic efficiency and the continuous operation of turbines. Our seasonal anti-ice coatings, which can be applied flexibly by drone, offer an innovative solution to temporary problems. In order to simulate realistic ice conditions and test the effectiveness of the anti-ice technologies under controlled conditions, our institute has an ice laboratory with an integrated wind tunnel.

Corrosion protection:

The prevention of corrosion and its consequential damage is an important issue for many sectors of the economy, as corrosion causes costs running into billions. For renewable energies, such as wind and solar energy, the relevance is particularly high, as the generation plants are exposed to extreme weather conditions.  Fraunhofer IFAM develops effective corrosion protection systems for the wind energy sector and operates accredited test laboratories. In addition, Fraunhofer IFAM advises companies on corrosion protection measures and offers training courses.

Ecological fouling protection and innovative cleaning processes:

In the offshore wind energy sector, we are developing biocide-free, ecologically and economically sustainable anti-fouling technologies and innovative underwater cleaning processes. These technologies are designed to interact synergistically with autonomous systems such as AUVs and ROVs in order to make maintenance, inspection and repair processes more efficient.

Autonomous inspection of wind turbines

The operation of wind turbines requires regular inspections and maintenance work. The aim is to detect wear and damage at an early stage and with little effort and to derive optimized maintenance and repair plans from this.

Highly automated drones or unmanned aerial vehicles (UAS) can make an important contribution to reducing costs and minimizing the risk for human inspectors. Furthermore, the use of transport UAS can be used to provide small to medium-sized spare parts at short notice and reduce operating costs and CO2 emissions (especially for offshore wind turbines). The Fraunhofer IFAM offers its applied research services in the following areas in particular:

Offshore Drone Campus Cuxhaven:

In Cuxhaven, we have established an innovation center for the further development of drone technologies for the inspection of offshore wind turbines. Our drone flights are designed to carry out comprehensive visual inspections to identify corrosion and damage to the rotor blades. These autonomous drones are equipped with high-resolution cameras and sensors to capture detailed images and data. Contact measurements and UT scans further improve the accuracy of our inspections by providing precise data on the condition of the turbine components.

AI-supported data evaluation:

Our advanced algorithms enable fast and accurate analysis of inspection data to assess the overall condition of wind turbines. This enables potential damage to be detected at an early stage and maintenance costs to be reduced.

Root cause analysis of damage

Root cause analysis of damage plays a crucial role in improving the durability and reliability of wind turbines. By identifying or analyzing the causes of component failures, we can develop targeted solutions to prevent future problems:

Mechanical load analysis and simulation:

We examine the mechanical and thermal loads to which wind turbines are exposed and simulate their behavior under real conditions. This enables us to predict the behavior of the components and identify potential weak points. In addition, we carry out thorough inspections for manufacturing deviations using non-destructive testing (NDT) and destructive testing methods.

Material testing and surface analysis:

Our advanced testing methods, such as scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS), provide in-depth insights into material properties and changes, which are crucial for the development of durable components.

Circular economy: Sustainable solutions for wind energy

We are committed to a sustainable circular economy in the wind energy sector. Our research focuses on maximizing resource efficiency and improving recycling processes to promote greener wind energy production. Our current approaches include:

Innovative thermoset resins:

We develop resins for adhesive and fiber composites that are designed to increase the performance and service life of wind power components while being more environmentally friendly than conventional systems.

Debonding on demand:

This technology enables the controlled separation of bonded components and materials, making it easier to dismantle and recycle wind power components.

Recycling of composite materials:

We are researching efficient processes for recovering valuable materials from composite structures, thereby reducing waste and conserving resources.

Life cycle analyses (LCA):

By systematically assessing the environmental impact of wind power components over their entire life cycle, we identify optimization potential and develop strategies to reduce their environmental footprint.

Our research is closely networked with the industry. By collaborating with leading companies and research institutions, we develop practical solutions that strengthen the competitiveness of the wind energy sector and accelerate the global introduction of renewable energies.