Researchers at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) are collaborating with the University of Stuttgart, Delft University of Technology, and the University of Colorado at Boulder on a project that uses lidar technology to “see” the wake of one turbine and how it affects other turbines.

Engineers mount a lidar system supplied by the University of Stuttgart on top of the U.S. Department of Energy GE 1.5-megawatt wind turbine as part of the collaborative Full-Scale Wake Steering Project. Photo by Dennis Schroeder, NREL.

The Full-Scale Wake Steering Project features a Stuttgart-designed scanning lidar mounted to the U.S. Department of Energy (DOE) GE 1.5-megawatt (MW) wind turbine located at the NWTC. Unlike previous lidar installations, however, this lidar mount (designed by NWTC engineers) is motorized to pivot independently from the turbine, enabling researchers to measure the entire turbine wake—even in cases where the turbine has yawed. The results are then modeled in NREL’s Simulator fOr Wind Farm Applications (SOWFA).

Each project partner brings its own unique capability to the project. NREL has the DOE GE 1.5-MW wind turbine, SOWFA, and expertise with implementing, analyzing, and designing wind farm control strategies. The University of Stuttgart provided the lidar device and supports the project through their lidar-based control expertise. Additionally, Steffen Raach of Stuttgart worked for 3 weeks at the NWTC to support the calibration and installation of the lidar following shipment. Delft University of Technology brought to the partnership models, data, and expertise in dynamic models and control to help NREL model the dynamic behavior of wakes. And, during the project’s analysis phase, the University of Colorado will join in interpreting the data.

“Wind farm control is garnering interest across the industry now, and field tests provide an important development in maturing the technology.  However, field tests of wind farm control strategies are challenging.  In the past, you could evaluate individual wind turbine controls by installing them on one turbine and comparing its performance with other nearby turbines,” Fleming said. “This is more challenging with wind farm control. For one organization to have everything from expertise in high-fidelity modeling to controls and test equipment such as a turbine and lidar is a tall order, so there are lots of reasons to collaborate on this work. Everything we learn from these big collaborative projects is beneficial to every partner.”