Max Bögl Wind AG and its hybrid towers are setting new benchmarks in electricity generation and regularly write success stories for the energy transition: The wind turbine towers from the Bavarian family-owned company are well-known in the industry for their high hub heights. They are therefore shining examples of an efficient and climate-friendly electricity generation, because the hybrid towers reach heights that cannot be attained with normal steel towers – and that is worthwhile. With every metre of hub height that a wind turbine gains, its annual electricity yield increases by 0.5 to 1 percent. Less wind turbulence and a significantly higher wind yield speak for high hub heights, especially in less windy inland locations. So that not only national and European wind farm operators benefit from the high heights of the hybrid towers, however, Max Bögl Wind AG has developed the mobile factory. This manufacturing plant makes it possible to produce hybrid towers virtually anywhere in the world. The first project has now been successfully completed in Thailand. Some of the highest wind turbine towers in Asia were built there, with a hub height of 156.5 metres. The company is now even among the top 3 nominees for the bauma Innovation Award 2019 in the category Construction Method with this manufacturing concept, which is unique in the world.
The hybrid towers from Max Bögl Wind AG have decisive advantages in comparison with all-steel wind turbine towers. It is the solid substructure of maintenance-free high-performance concrete that makes high hub heights and the use of high-power systems of the latest generation possible at all. This leads to a higher yield and increases cost-effectiveness. So that this efficient form of electricity generation can be used anywhere in the world, engineers from Max Bögl Wind AG have developed the mobile factory.
Before the first tower could roll off the production line in Thailand, a complete manufacturing plant had to be shipped in 267 sea containers from the German headquarters in Sengenthal in the Upper Palatinate to Huai Bong in Thailand – 17,000 kilometres away. Having arrived at the destination, a good 260 kilometres north-east of Bangkok, the world's first mobile factory for wind turbine towers was assembled within three months from around 3,500 tonnes of high-grade equipment. A short while later, production began with local raw materials and a workforce of around 200 people, most of them Thais.
The assembled mobile factory consists of four halls on a floor area of 40,000 square metres. Situated around the halls there are necessary production plants such as a concrete mixing plant, a water conditioning plant and an ultra-modern concrete grinding system. The advantages of the mobile factory are clearly recognisable: local raw materials and workers turn the hybrid towers into local content and increase the cost-effectiveness of the project. The high quality standards of the German factory production are thereby retained. Less heavy-duty transport relieves the infrastructure, the climate and the environment. The mobile factory for the project in Thailand was built only 30 kilometres from the wind farm.
"For all of us at Max Bögl the first project with the mobile factory was like discovering a new continent. Everything was planned and calculated down to the tiniest detail so that there wouldn't be any surprises", relates Udo Hiller, Project Manager Thailand, Central Area Manager for wind turbines. Prior to this there had never been such a project involving the shipping of a complete manufacturing plant to the other side of the world and erecting it in a different cultural group and tropical weather conditions. Technical adjustments, for example to the concrete mixing plant, had already been implemented by the engineers in Germany so that the processing of the high-performance concrete used and adherence to the permissible fresh concrete temperature could be guaranteed. The relatively large unknown factor concerned the quality of the ingredients and raw materials for the high-performance concrete required. Having expected to be working locally with concrete of the strength class C60/75, a much better composition of the local materials ultimately even enabled a concrete quality of the class C100/115 to be produced. The result: the concrete parts of the hybrid tower could be built earlier and the final strength attained faster. Similarly, the tendency towards a higher strength class will have a positive effect on the fatigue limit of the concrete.
"It wasn't just down to the technology and materials that everything went so smoothly. The human relationship between our employees and their Thai colleagues made a major contribution to the success of the project", says Udo Hiller. The Max Bögl managerial staff received training in advance in order to get to know the country, the culture and the local workforce: "There isn't such a strict separation of job and private life in Thailand. We very quickly gained an understanding of the Thai mentality and learned how to respond correctly to the colleagues and to motivate them", Udo Hiller adds. The good relationship between the German and Thai workers has led to one or the other friendships continuing beyond the end of the project. This perception is also confirmed by Jens Freytag, Project Manager Assembly and On-site Logistics for the Thailand project: "It wasn't just great to erect 90 wind turbines. It was also great to see the enthusiasm of the Thai colleagues and residents about this ingenious product. Looking back, I see this project as more of a know-how transfer rather than just a construction site like other classic big projects."
Millimetre-precision anywhere in the world
The heart of the mobile factory is the CNC concrete grinding system. It ensures that the concrete segments of the hybrid tower are ground precisely to 1/10 millimetre in the same quality as with stationary plants. For example, the concrete tower can thus also be erected internationally under any weather conditions. With a production duration of approx. two days per tower, the mobile factory operates very quickly and efficiently. In comparison with other suppliers of wind turbine towers, the mobile factory from Max Bögl Wind AG can be modularly extended through the semi and fully automated circulation system, depending on the project requirements.
In December 2018 the last hybrid tower left the production hall of the mobile factory in Huai Bong. Max Bögl Wind AG has thus successfully erected 90 wind turbine towers, each with a hub height of 156.5 metres and thus some of the highest wind turbine towers in Asia, with the first use of the mobile factory – far away from home and in German factory quality. Once the plants and rotor blades have been installed, all of the wind turbines are to be connected to the grid in March and Thailand will have come a step closer to its goal of increasing its renewable energies share to 30 percent by the year 2036. Jens Freytag was always confident the project would be a success: "It takes a lot of preparation and ambition to construct this plant in an emerging market such as Thailand, to reinforce and cast 90 foundations and to assemble more than 7,000 precast elements, and you must never lose your focus. Thanks to an outstanding team and the right know-how of our engineers, we were always able to pursue our goal on site: to produce and assemble the product with a high performance using local resources, with maximum occupational health and safety standards and in German quality."
Together against climate change
"The project in Thailand is now complete, but our mission is by no means over", says Udo Hiller. The mobile factory will remain assembled in Thailand for the time being while the next possible assignments are being considered. "We want to apply the experience in precast element production, which we have gained in Germany and already transferred to Thailand, to other markets as well in future. Only together and with courageous ideas can we counteract the advancing climate change."
Max Bögl Wind AG
92369 Sengenthal, Germany
T +49 9181 9090