Wind power has making inroads even into mountainous regions with irregular winds and air turbulence brought on by the rough terrain. Six partners from Wind-ForS, a wind energy research cluster in southern Germany, are now investigating how wind turbines can best be operated at these locations. The collective is planning to set up a field-test research site with two systems and four meteorological measurement towers in the Swabian Alps.
According to the Global Wind Energy Council, the worldwide installed base is growing every year with new power plants that collectively produce some 63,000 MW, around a fifth of which is generated in mountainous regions. Installations on flat terrain are easier to operate than plants erected in rugged terrain where yield forecasts are more uncertain, wear and tear are greater, and maintenance costs are higher. The WindForS research cluster now aims to answer the question of how to optimize these systems' performance and extend their service life. In a team headed up by ZSW, these wind energy experts are now planning a field-test research site in the Swabian Alps, at Stöttener Berg near Geislingen an der Steige.
"This location offers the ideal conditions for our research," says Project Manager Andreas Rettenmeier. "The prevailing west wind is accelerated across the crest of the upstream escarpment, creating irregular flows and turbulence. What's more, the region has a high average annual wind speed," explains the ZSW scientist. These factors are typical at wind turbine sites in complex mountainous terrain and perfect for developing and testing new technologies. WindForS carried out a project called KonTest to investigate the location and its prevailing conditions.
Measurement sensors from the foundation to the rotor blades
Now this project is to be followed up by another named Wind Science and Engineering in Complex Terrain (WINSENT), the purpose of which is to set up a test site to serve as a platform for research and industry. It is to be equipped with two wind turbines that each generates around 750 kW nominal output with 75 meters hub height, 50 meters rotor diameter and a total height of 100 meters. One of the project's USPs is that scientists will have unrestricted access to all control technology and engineering data. This way, they will be able to precisely analyze these systems' behavior. During their construction, the wind power plants are to be equipped with measurement sensors from the foundation to the rotor blades.
A 100-meter tower is to be installed in front of and behind each system to rapidly measure meteorological parameters such as wind speed and direction, temperature, air humidity and air pressure. State-of-the-art laser technology will also serve to measure the wind power plants' in-flow and wake.
Development of a new operating system
"A wind energy field-test research site of this size and in such complex terrain is one of a kind worldwide, and of great importance to researchers and the wind power industry. The results of our analyses will be scalable to large commercial plants and provide fresh momentum for the industry, "says Andreas Rettenmeier.
To view a video of the projected field-test research site, visit: www.windfors.de/testfeld.html
The partners in this project aim to achieve technological improvements in follow-up projects, for instance, to design rotors that will be lighter, quieter and more powerful. Another goal of this project is to develop and test a new operating system that will enable plants to respond to changing wind conditions with intelligence and greater precision. New machine learning methods will also be used to improve forecasts of wind power feed-in and to optimize models for integrating power-to-gas, battery and other storage means into the future energy system.
The Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) is coordinating the project. Its partners are the University of Stuttgart, Eberhard-Karls University of Tübingen, Technical University of Munich, Karlsruhe Institute of Technology and Esslingen University of Applied Sciences.
The German Federal Ministry for Economic Affairs and Energy is funding the three-and-a-half-year WINSENT project (FKZ 0324129A-F) with around EUR 10.4 million. Also the Ministry of the Environment, Climate Protection and the Energy Sector Baden-Württemberg is funding the project with EUR 1.2 million.
Silke Funke / ZSW