Energy without end
Wind power
In the year 2009 wind turbines with a total output of about 13 gigawatts were installed in China, doubling power output when compared with the previous year’s level. Nordex, a Rexroth customer, set up its own production plant in China in 1998, making it one of the first suppliers of wind turbines to do so.
In the year 2009 wind turbines fed about 158 gigawatts of power into the global grid. This corresponds roughly to the output of 280 nuclear power stations. BTM Consult in Denmark estimates that the amount of power extracted from the energy of the wind will more than double by 2013, to 340 GW. Major contributions are made here by the markets in the emerging economies such as China and India. Responding to rising energy demand, those markets will be turning more and more to renewable energies. Additional potential for expansion is offered by capturing energy in offshore wind farms, built on the sea bed, and by replacing older generating plant (repowering).
Power production costs are the yardstick for the economics of wind turbine arrays. They have to stand up to a comparison with conventional forms of energy. Wind farm operators thus expect their turbine suppliers to deliver high-performance, reliable power plant technology at the highest quality standards. With a broad program of drive concepts, each tailored to a particular wind turbine design, Bosch Rexroth has carried out exhaustive work to meet these market demands — right from the pioneer days of this technology. Precise azimuth drives ensure exact orientation on the wind. Rexroth offers both electromechanical and hydraulic options for adjusting blade pitch. The main step-up gearboxes transform the slower motion of the rotor shaft to the faster rotation speed needed to run the generator.
As the world’s largest independent supplier of gearboxes for wind turbines, Rexroth manufactures these units at the main plant in Witten, Germany, and at the new plant in Nürnberg. The factory in Beijing serves the new markets in China and Asia. Rexroth puts its faith in both ongoing innovation andlocal presence in the target markets. Examples include the intelligent adjustment of blade pitch to increase effi- ciency and more compact designs for differential gearboxes, making an important contribution to reducing the mass of the nacelles in multi-megawatt systems. Innovation efforts — in collaboration with various universities and research institutes and with the corporate research units at Bosch, the parent company — are laying the foundation for efficiency, availability and a long service life. That makes for ongoing success in the wind energy market, a sector with a promising future.