Extraction of the inherent nature of wind speed using wavelets and FFT

• Wavelets have been utilized to understand the fluctuating nature of wind.
• Wind speed changed by ± 0.6 to ± 1.6 knots over a period of about 10 years.
• The annual fluctuation in wind speed is ± 1.3 to ± 3.0 knots.
• The largest change in wind speed occurs half-weekly by about ± 1.6 to ± 3.8 knots.

Due to technological advancement, availability of multi-megawatt wind turbines, ease of installation and maintenance, economic compatibility and commercial acceptance, wind power is being used globally for both grid-connected and off-grid applications. The wind power is intermittently available due to the fluctuating nature of the wind and hence needs to be understood well. Its variability was studied in this paper both in time and spatial domain. The present work utilized daily mean values of wind speed from different meteorological stations spread over the Kingdom of Saudi Arabia in conjunction with wavelet transform and fast Fourier transform power spectrum techniques to understand the dynamic nature of the wind at nine stations. The study found that wind speed changed by ± 0.6 to ± 1.6 knots over a long period of about 10 years depending on the locations. The long-term mean wind speed of 5.6, 8.9, 6.25, 8.1, 6.0, 7.1, 6.0, 8.6 and 7.3 knots was obtained at Abha, Dhahran, Gizan, Guriat, Hail, Jeddah, Riyadh, Turaif and Yanbu, respectively.