Empirical correlation between hub height and local wind shear exponent for different sizes of wind turbines

The increasing rate of adverse environmental events has made people from all walks of life more aware of the utilization of clean and renewable sources of energy. Technological advancement and the availability of efficient wind turbines of a few tens of kilowatt to multi-megawatt sizes which cover all human applications have made the utilization of wind power the technology of choice. For its optimal utilization, the site-dependent analysis of the wind and its variation with height and the economics of increasing the tower height (hub height) have become necessary factors. This paper proposes a new correlation for the estimation of optimal hub height for harnessing the power of the wind on an economically competitive basis. The optimal hub heights for Dhahran, Dhulom, Gassim, Juaymah and Rawdat Ben Habbas were found to be 64, 66, 81, 70 and 82 m, respectively. Furthermore, seven empirical correlations were developed for seven sites for wind turbines of rated power of 600 to 5000 kW. Wind speed measurements made at 20, 30 and 40 m at seven sites were used in the present work.