The market for offshore wind energy is growing, and the question is how to build floating offshore wind turbines in steep water. By combining different PEMA welding automation solutions, we can answer the challenge of building floating wind farms, turbines, and floating foundations.
The offshore wind energy industry is booming, and the current trend is towards building even bigger structures farther out to the sea. With new technology being developed, it is possible to put wind turbines far from the shore. The farther out the towers are, the more stable the wind is which also means more energy. However, the longer the distance from the shore, the harsher the conditions are and the deeper the sea gets. This requires a lot from the offshore wind turbine design, foundation, methods, and welders.
The wind tower monopiles are approximately 10 m in diameter and they are constantly growing. They can be put in the seabed at the depth of 60 m and serve as the base for wind towers that reach over 300 m into the sky. However, the deep water also creates challenges. As the water gets deeper an excellent solution is offshore wind turbine floating foundations. Juhani Tuomola, Wind Energy Application Specialist at Pemamek, tells that new technology is developed all the time and the trend is towards even bigger structures:
“The offshore wind energy industry is booming at the moment, and the development speed is high. The trend is going towards bigger structures, soon, there will be monopiles that are 15 m in diameter and 120 m in length. Floating wind turbines with floating foundations enable us to put the wind towers in places, where it hasn’t been possible before. The question is how to build durable foundations that will last in the harsh offshore conditions.”
Welding automation to build floating offshore wind turbine foundations
A floating foundation or structure means that the wind tower base is kept in place with the help of long cables that are attached to the seafloor. This makes it possible to put wind towers far out, even to the depths of 200-300 m of water. The offshore wind turbine foundation design is different but has similarities to the technical structures that are used in submarines, shipbuilding, oil rigs, and wind tower manufacturing. By combining different PEMA welding automation solutions, it’s possible to build these huge structures with the necessary preciseness.
One example of the solutions is the modern technology that Pemamek uses that makes it possible to weld the thick and heavy plates together perfectly to last in harsh marine conditions. With narrow or semi-narrow grooves both time, resources, and energy are saved, and it results in high quality and safety. Pemamek’s long-stick-out process with WeldControl 500 software and laser seam tracking is one of the safest and most efficient ways to weld. With the help of the software, all guesswork is eliminated. One operator can do the work of multiple welders and do multiple welds at one time.
Production of offshore wind turbine foundations
Foundations for floating offshore wind turbines can be built in different ways. Three common styles of floating foundation structures are spar, tension leg platform, and semisubmersible. Spar foundation structure can be built by combining different PEMA welding solutions such as an assembly station, flange fitting, PEMA Column & Boom for longitudinal and circular welding, milling machine, and WS2 welding platform.
A tension leg platform can be built by using PEMA robotic welding solutions: PEMA VRWP-C and PEMA VRWP-X2. These solutions are often used in robotic welding in the shipbuilding industry. PEMA VRWP-C, for example, has a working width of 5 meters (16 feet) and the length of the working area can be expanded in 6 meters (20 feet) modules.
Semi-submersible foundations are produced with the help of the PEMA node welding station and PEMA pile assembly station. For section assembly and welding, Pemamek can provide assembly line, WS2 welding platform, PEMA column and boom, and rollerbeds.
Examples of offshore wind turbine foundation types
The video features three examples of floating offshore wind turbine foundation types: spar, tension leg platform, and semisubmersible. It also shows the PEMA welding automation solutions that are needed in the manufacturing of the structures.