School of Meteorology Seminar Series presents...
An 18-year Spatial Climatology of Large Wind Ramp Events at 80-meters [Thesis Seminar]
Kristen Bradford
School of Meteorology
27 November 2012, 3:30 PM
National Weather Center, Room 1350
120 David L. Boren Blvd.
University of Oklahoma
Norman, OK
The understanding of wind ramp events—defined as large and rapid changes in wind power output over a short period of time—is of increasing importance, as their unpredicted occurrence can prove to be immensely costly for the wind energy industry. However, the majority of past studies have focused on one particular location, yielding site-specific results. It would therefore be advantageous to compile a climatology examining ramp events across a particular region, but observations at turbine hub height are sparsely distributed. This study devises a method to compile spatial climatologies of wind ramps using a dense network of surface observations. Wind speeds at 80 m were extrapolated from 10 m observations recorded by the Oklahoma Mesonet between 1994 and 2011. The ramps were assessed in terms of their annual and diurnal distributions. Spatial variations in ramp magnitude, up-ramps and down-ramps, and high speed shutdown (HSS) cases were also investigated. Finally, the extrapolated results were compared to ramp observations from one 80 m tower located in northwestern Oklahoma. While a few inconsistencies were detected between extrapolated and observed ramping behaviors, overall it appears that the employment of surface observation networks could prove to be extremely useful in the approximation of long-term ramp climatologies.