University researchers at the newly opened WiValdi research wind farm on the River Elbe are investigating how several wind turbines in close proximity to each other influence each other. Three measuring masts play an important role here.
A globally unique large-scale research facility was opened today in Krummendeich near the mouth of the Elbe into the North Sea, in which the University of Oldenburg is involved via the Centre for Wind Energy Research (ForWind). The WiValdi research wind farm (short for "Wind Validation"), operated by the German Aerospace Centre (DLR), consists of two state-of-the-art wind turbines equipped with sensors and measuring devices, another test turbine and five meteorological measuring masts.
"Over the past 20 years, ForWind has been involved in many wind energy research projects and participated in numerous measurement campaigns on land and at sea. This wealth of experience has been incorporated into the design and content planning of the wind energy research park in Krummendeich and thus forms the basis for ForWind's future research," explains turbulence expert Prof Dr Joachim Peinke from the University of Oldenburg, scientific spokesperson for ForWind, which is a joint research institution of the Universities of Oldenburg, Bremen and Hanover.
"Building block for a successful energy transition"
Lower Saxony's Minister President Stephan Weil wished the new wind farm every success at the opening ceremony: "Lower Saxony is the number one wind energy state. The WiValdi research park, in which the state of Lower Saxony is investing 16.4 million euros, demonstrates this once again. With WiValdi as a flagship project for energy research, we are realising another important building block for a successful energy transition. WiValdi is an excellent example of how we can utilise the opportunities offered by renewable energies to protect our environment, advance our economy and create jobs through innovation. I would like to thank everyone involved - first and foremost DLR and its partners ForWind and Fraunhofer IWES from the wind energy research network - for their forward-looking commitment."
At the heart of the globally unique test field are two conventional wind turbines in the multi-megawatt class, whose rotor blades reach up to a height of 150 metres. One of the turbines stands in the lee of the other. One of the most important research questions: What effect does turbulence from the front turbine have on the rear wind turbine? To find out, a so-called measuring mast array planned by ForWind is located between them. This arrangement is important for the future, because with the high number of new wind turbines and wind farms currently planned, the turbines will inevitably be closer together.
The arrangement of sensors specially developed for WiValdi at the University of Oldenburg makes it possible for the first time to measure the turbulent wind conditions between turbines with high temporal and spatial resolution. The measuring devices are installed on irregularly distributed booms, some of which are several metres long, to the side of the masts. They are arranged in such a way that they record wind speed, temperature or humidity in detail on a vertical surface between the two wind turbines. Another measuring mast in front of the front wind turbine records the incoming wind field. The towers and rotor blades of the turbines are also equipped with measuring systems that were planned and developed by ForWind members at the universities of Bremen and Hanover.
Measuring turbulence with unrivalled precision
"Thanks to the special configuration of the booms and the measuring instruments on the three masts, we can measure the turbulence generated by the front wind turbine with unrivalled precision," explains Peinke. For the first time, it is possible to record the turbulence on different scales at full scale. The researchers want to use the data obtained to determine, for example, how turbines can be optimally positioned in wind farms in order to maximise efficiency and meet the needs of the electricity grid.
The data from the "free field" forms the basis for creating digital models of both wind farms and individual turbines, for example. "There is still a lot of potential for optimisation in the operation of wind farms, especially as the turbines are getting bigger and the wind farms are becoming more complex," emphasises Peinke. Together with the operating data of the turbines, the findings from the research wind farm will help to better understand the complex overall dynamics of the wind turbine and to be able to model and simulate them. This includes damping models, early damage detection, ice detection on the blades and material fatigue modelling.
After around two years of construction, commissioning is currently in full swing. WiValdi has already fed electricity into the grid during trial operation. Research projects have been launched and initial data has been collected.
The wind energy research park is funded by the Federal Ministry of Economics and Climate Protection (BMWK) and the Ministry of Science and Culture of Lower Saxony. The Wind Energy Research Park was developed and established by DLR together with the partners of the Wind Energy Research Network (FVWE). The FVWE pools the expertise of around 600 researchers in order to provide impetus for the energy supply of the future. It consists of three participants: the DLR, ForWind and the Fraunhofer Institute for Wind Energy Systems (IWES). WiValdi is also available to the wider research community in science and industry for joint projects.
