Two multiyear projects now being undertaken in Europe aim to improve the technology behind wind power generation: one seeks more efficient and cheaper ways to make the blades, and another wants to swap in a new generator to make the turbines smaller and lighter, and able to be scaled up in power output.
In Germany, the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) has expanded a previous research project into finding ways to automate the manufacturing of rotor blades. Rotor blades make up about a quarter of the total cost of a wind turbine, much of that in manual labor; switching to large-scale industrial production could accelerate the process, improve the quality, while reducing costs. "Rotor blade producers are under great cost pressures which we will tackle with automation," states Florian Sayer of the Fraunhofer IWES.
The IWES and 18 partners are undertaking a five-year joint project, "BladeMaker," aiming to reduce production costs "by well over 10 percent." Work will begin with analysis of work processes and technologies involved in wind rotor blade production, then assessment of where automation might be a better option. For example, explains Sayer, current wind rotor blades are build with a "vacuum infusion process," in which two blade halves are reinforced with fiberglass or carbon-fiber matting (an almost completely manual process); a vacuum environment is created and resin injected to bond the materials, which after hardening are joined and varnished. At the end of the project a demonstration center will showcase the various process steps, and design research and development of rotor blade production.
The BladeMaker project, running until Sept. 2017, is funded with €8 million from the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU).
Update: In an email response, Sayer elaborated on the potential of reducing the reliance upon vacuum processes: "A huge potential lays in the optimization and automation of the composite material lay-up (fiber, tapes, foams, etc.) as well as in the mechanical finishing of the products," he said. One option is thermoplastic tape laying, which opens up the ability to weld the structures. Typical polymer systems with "wet layups," such as winding, are also possible but raise quality questions, he noted.
Meanwhile, in Spain, another multiyear project seeks to reduce the cost of offshore wind turbines by about 30% through the development of a new compact superconductor-based generator. The SUPRAPOWER project (SUPerconducting, Reliable, lightweight, And more POWERful offshore wind turbine) spearheaded by Tecnalia after four years of development on a patented concept, aims to design a 10-megawatt offshore wind turbine based on a superconducting generator. Conventional geared and direct-drive permanent magnet generators are difficult to scale up any bigger due to size and weight, which drives up costs for both fixed and floating foundations. Radically reducing the head mass "may be the only technology" able to provide better power scalability, weight reduction and reliability, according to Tecnalia.
Specific goals of the project, which began in December 2012 and runs through the end of November 2016, include: reducing turbine head mass, size, and ultimately cost of offshore wind turbines by about 30 percent, using the compact superconducting generator; realizing lower operating and maintenance and transportation costs through use of a direct drive system; and increasing the reliability and efficiency of high-power wind turbines through use of drive train-specific integration into the nacelle.
Most of the project's roughly €5.4 million budget will be funded by the European Commission as part of its Seventh Framework Program. Industrial partners in the SUPRAPOWER project include Acciona (wind turbine manufacturing and energy divisions), Columbus Superconductors (superconducting wire developer), Oerlikon-Leybold Vacuum (cryogenic systems), and D2M Engineering (offshore engineering firm). Research partners include the Institute of Electrical Engineering Slovak Academic of Sciences, University of Southampton, and Karlsruher Institut Technologie.
Lead image via Tecnalia