Proposed wind measurement and analysis approach for evaluating a prospective wind plant site

摘要

On the basis of research results, cooperative efforts with wind energy developers, and work with meteorological consultants, Pacific Northwest Laboratory (PNL) has proposed an approach for performing wind measurement assessments for prospective wind plant sites. The primary goal of this approach is to effectively balance comprehensiveness with expense. The approach begins with the acquisition of high-resolution digital terrain data for the site. These data are used in computational and visual analyses to determine the best locations for a reference tower and several satellite towers used for wind measurements. The reference tower has wind sensors at three levels: 20, 30, and 40 m. The satellite towers have one sensor at 30 m. The sensors measure the vertical wind speed as well as the horizontal speed and direction. The sampling rate must be at least 4 times per second. The data acquisition system keeps track of turbulence statistics that are saved at intervals from ten minutes to one hour. Statistics for the 30-m level at the satellite towers, as well as the reference tower, provide the mean and variance of the total speed and covariances of the component speeds. The data base produced by this approach over 1--2 years should be valuable for both routine and in-depth analyses. This approach takes advantage of some recent technological developments. It is not being proposed as a standard at this time, but as a tool to be refined with experience.