Pleasant Valley Wind Farm
Site Description
Pleasant Valley Wind Farm is located near Hayfield, Minnesota in Dodge and Mower counties and is owned and operated by Xcel Energy. It was constructed by Renewable Energy Systems Americas Inc. (RES Americas) and began operation in 2015. The wind farm consists of 100 Vestas V100 turbines, totaling an installed capacity of 200 MW. Each turbine has a 100 meter rotor diameter and 95 meter hub height. The site’s wind characteristics were measured from 2007 to 2009 for planning purposes. Based on the measurements, the long term annual mean wind speed at 80 m is 7.4 to 8.1 m/s, and the dominant wind directions are from the south and northwest.
Current Monitoring
Measurements are being done to get as comprehensive a dataset as possible. This is done by measuring at various distances from turbines, orientations, and meteorlogical conditions.
Site Description
University of Minnesota's Eolos Wind Research Station provides an unmatched resource in wind energy research. The station consists of a 2.5 MW Clipper C96 wind turbine, 130 meter tall meteorlogical tower located 160 meters south of the turbine, and deployable WindCube LiDAR system. Unlike other wind turbines, the Eolos turbine logs SCADA information at 1 Hz to University of Minnesota servers. The turbine is also fitted with strain gauges in the blades and at the base of the tower, and accelerometers in the blades. The meteorlogical tower records wind speed, direction, temperature, and relative humidity at 20 Hz. The LiDAR is capable of measuring wind speed and direction from 40 to 200 meters.
2012 Dataset
In June of 2012, United Technology Research Center (UTRC) in collaboration with the University of Minnesota – St Anthony Falls Laboratory (SAFL) performed day time wind turbine acoustic measurements at the Eolos Wind Research Field Station. Thirty-six microphones measured noise emission from the wind turbine with a directivity array. This array had microphones located at a radial distance of 102 meters from the wind turbine with equal spacing between microphones fully surrounding the turbine. The microphones were sampled at 32,768 Hz (Nyquist frequency 16,384 Hz) and high passed filtered at 20 Hz. Three infrasound microphones were used in addition to the audible range microphones. The infrasound microphones were placed around a single microphone in a 10 meter diameter circle. Microphones and accelerometers were also placed throughout the turbine nacelle.
Current Monitoring
To build on the 2012 data, noise measurements at night time and varying distances will be recorded with a stronger focus on low freqeuncy noise, infrasound, and amplitude modulation.