OU BLISS sponsors seminars every other Friday from 2-3 pm in room 5390 of the National Weather Center. Members of BLISS, as well as outside guests, will speak on a variety of topics related to boundary layer research, including fieldwork, laboratory simulations, and more. All are welcome, and light snacks will be served. For a schedule of upcoming seminars, see the calendar.

Next Seminar: 4/19/13, 2PM in NWC 5390:

Using Ground-Based Measurements to Improve Wind Power Forecasts

Jennifer Newman

Environmental concerns and rising fossil fuel prices have prompted rapid development in the renewable energy sector. Wind energy, in particular, has become increasingly popular in the United States. However, the intermittency of available wind energy makes it difficult to integrate wind energy into the power grid. Thus, the expansion and successful implementation of wind energy requires accurate wind resource assessments and wind power forecasts.

This presentation will examine two major challenges involved in wind power forecasting: 1) the estimation of hub height wind speeds based on surface measurements and 2) the estimation of turbulence effects on wind power production based on remote sensing data. The first topic is significant, because most wind speed measurements are taken at 10 m above ground level while modern turbine hub heights range from 80 to 100 m. Depending on the amount of wind shear present in the atmosphere, the wind speeds experienced at hub height can differ substantially from the wind speeds experienced close to the ground. In this presentation, several common extrapolation methods are evaluated using cup anemometer data from an Oklahoma Mesonet site and a tall meteorological tower operated by the Oklahoma Wind Power Initiative. A traditional power law is evaluated as an extrapolation method, in addition to two extrapolation methods based on Monin-Obukhov similarity theory.

The actual power produced by a turbine is affected by the wind speeds and turbulence levels experienced across the turbine rotor disk. Because of the range of measurement heights required for wind power estimation, remote sensing devices (e.g., lidar) are ideally suited for these purposes. However, the volume averaging inherent in remote sensing technology produces turbulence estimates that are different from those estimated by a sonic anemometer mounted on a standard meteorological tower. In order to directly compare turbulence measurements made by a Doppler lidar to those made by a sonic anemometer, a WindCube lidar was deployed at the Southern Great Plains Atmospheric Radiation Measurement site in Fall 2012. The WindCube lidar was sited near a 60-m tower instrumented with several sonic anemometers. An initial analysis of the mean wind speeds and turbulence parameters measured by the lidar and a sonic anemometer at 60 m will be presented. In addition, plans for a future field campaign will be discussed.

Past Seminars

04/05/13 - Greg Blumberg: Developing a Statistical Thermodynamic Retrieval for Ground-Based Infrared Spectrometers

04/05/13 - Tim Bonin: Observed Characteristics of Low-Level Jets During the Lower Atmospheric Boundary Layer Experiment

03/08/13 - Charlotte Wainwright: Virtually Sampling the Developing Boundary Layer

02/08/13 - Xiaoming Hu: Simulations of thet Low-Level Jet with WRF

01/25/13 - Dr. Petra Klein: Impact of the Low-Level Jet on Urban Heat Island Intensity and Nocturnal Ozone Concentrations in OKC