Parametric analysis of wind siting efficiency

The effect of wind climatic characteristics on the efficiency of the WECS is examined by means of the Weibull general model and a simple model of power curve. Two efficiency parameters—the plant utilization factor (Fu) and the site effectiveness (ε)—are considered as functions of three parameters: the Weibull shape parameter (k), a dimensionless mean wind speed (α), and the design ratio between rated and cut-in speed (φ). It is shown that only for intermediate values of α and φ the plant utilization factor can be considered independent of k, being otherwise either improved or penalized in no negligible measure by it, depending on the values of α and φ. The effect of increasing k on the site effectiveness is always beneficial. The effect of increasing α is beneficial for the plant utilization factor but largely penalizing for the effectiveness. However, no maximization is possible for neither of the efficiency parameters. shown that the correct use of Fu and ε for comparison is significant only for a given WECS, while the WECS data have to be used when comparing different or modified wind machines. The data of 35 commercial WECS are examined to show that the common assumption of constant rated or maximum efficiency is not acceptable.