A comprehensive measurement programme was carried through 300 kW Nordtank stall-regulated horizontal axis wind turbine. These turbines were erected at the test station for windmills by Hurghada Wind Energy Technology Centre. To the extent necessary to understand the measurement carried out, all experimental set up systems must be described. This paper describes the annual wind speed variability in Hurghada city in period (1973-2001). The wind speed and direction were measured on the latitude of meat masts as, 10, 24.5, and 31 in. These stations were operated since 1986. The wind data was recorded from the instruments with a scanning rate of about 2 Hz and the data was subsequently stored as consecutive 1-h average values. Simultaneously, various types of monthly statistics were accumulated. Also, the study discusses the effect of this wind variability on the power curve of Hurghada farm wind turbines. The results show that, if the annual mean wind speed varies by +/- 10% around a long-term average value, the corresponding natural variability of the available wind energy is about +/- 25%.