2011 WIND INDUSTRY in gERMany - Wind-Energy-Market

Economic reportTechnology – turbines get biggerthanks to high-techWind turbines have continued to grow in size over the past few years. On average,turbines that were erected in Germany in 2010 had a rated capacity of just over 2 MW.According to the German Wind Energy Institute (DEWI), half of the wind turbinesinstalled in Germany fell into the 2 MW class and a further third into the 3 MW class. Thisprogress is enabled and supported by continuous innovation in design, construction,components and maintenance concepts.It takes a modern turbine less than amonth to feed into the grid the power thatcould be generated in an entire year by aturbine installed in 1995. Back then, turbinescould achieve a rated capacity of600 kW and a rotor diameter of 46 metres.Today’s top-class turbines now achieve arated capacity of 7.5 MW with a rotor diameterof 127 metres and a total height ofnearly 200 metres. That is enough to supplyaround 6,000 households with power.Meanwhile, the industry is preparing forthe next class of modern turbines. Somemanufacturers are already designing 10 MWturbines and scientists are speculatingabout 20 MW turbines.For years, wind turbines have achieved anearly constant availability of 98 %. Toensure that this high standard is maintained,the majority of modern turbineshave condition monitoring systems. Here,sensors monitor components in the drivetrain to diagnose faults before damage iscaused to the turbine. They are connectedto the manufacturer’s or service provider’scentral control computer. Operators canuse this to better plan service operationsand maintenance logistics. In offshorewind farms, where unexpected faults andfailures at sea cannot be remedied asquickly as on land, monitoring systems arealready standard.In addition, gearless turbines have recentlybeen experiencing a renaissance. In thistype of design, the rotor drives the generatordirectly. This means that there is noneed to convert the slow rotation of therotor in light winds into a faster rotationusing a gearbox. According to informationpublished in neue energie magazine, theworld market share of the capacityinstalled in 2009 from gearless turbineswas 16 %. This technology is also used inthe top-class turbines generating 7.5 MW.The weight of turbines – and therefore thematerial costs – has also reduced considerablyin relation to performance. As well asthe common steel construction, towers arenow also built in a mixed design comprisinga concrete base and steel upper part.Lattice towers are also making a comebackand can reach heights of up to 160 metres.The rotors too are undergoing continuousdevelopment. This has allowed noise emissionsto be reduced, for example. And tokeep light disturbance at night to a minimum,the navigation lights for air trafficcan be integrated in the rotor tips.Wind industry in Germany21