Research Abstracts 1995-1996: Report No. 96-01

Walker, S.N. and P.L. Barbour, "Sub-Hourly Wind Data Assessment - Juniper Point, Washington - march 1995", OSU Wind Research Cooperative, WRC Report No. 96-01, September 15, 1995, 56 pp., $14.00.

The need exists to understand more about the behavior of the wind on time scales less than one hour in the Pacific Northwest's complex terrain.  Two data sets of one-minute averaged wind speed and direction for Juniper Point, Washington have been provided to the OSU Wind Research Cooperative for analysis by fellow WRC member FloWind Corporation.  Report WRC 95-01 examined a 11 day record of one-minute averaged wind speed and direction data for three sites (5, 8, and 12) in late October 1994.  this report examines an 8 day record taken in late March 1995 for three sites (5, 8, and 18).  Basic time series statistical and frequency domain analyses have been performed on this data.  The wind speed data was converted.  The format of the report is the same as the previous report to allow the reader to make comparisons.

Several observations were made in reference to this most recent set of data.  These observations were consistent with previous observations.  Caution should be exercised when generalizing these observation to other time periods or locations.
 

1. Data needs to be sampled for averaging periods of five minutes or less to examine power output variations.
2. For energy calculations, hourly averaging is a reasonable approximation until more sophisticated wind turbine dynamic modeling tools are available and practical to use.  This later data set did show estimate improvement by using the hourly standard deviation and assuming a Gaussian distribution over the hour to calculate energy.
3. The rate of power change - frequency distribution is altered when sites are combined.