Abstract
The recent increase in energy costs, driven by a surge in oil prices, has increased world-wide efforts on the exploitation of renewable/wind energy resources for environment-friendly sustainable development and to mitigate future energy challenges. Moreover, experience in the wind energy industry has reached high levels in the field of manufacturing and application. This inevitably increases the merits of wind energy exploitation. In order to exploit wind resources, through the establishment of wind power plants, specific attention must be focused on the characteristics of wind and wind machines. The literature indicates that wind-energy resources are relatively better along coastlines. In the present study, long-term hourly mean wind speed data for the period 1986-2003, recorded at Dhahran (Eastern Coastal region, Saudi Arabia), has been analysed to examine the wind characteristics including (but not limited to): yearly/monthly/diurnal variations of wind speed, frequency distribution of wind speed, impact of hub-height/machine-size on energy production, etc. Data have been checked/validated for completeness. Data analysis indicated that long-term monthly average wind speeds ranged from 3.8 to 5.8 m/s.
Concurrently, the study determined monthly average daily energy generation from different sizes of commercial wind machines (150, 250, 600 kW, etc.) to assess the impact of wind machine size on energy yield. The study also estimated annual energy production (MWh/year) from wind farms of different capacities (3, 6, 12, 24 MW, etc.) by utilising different commercial wind energy conversion systems (WECS). It was observed that, for a given 6 MW wind farm size, a cluster of 150 kW wind machines (at 50 m hub-height) yielded about 32% more energy when compared to a cluster of 600 kW wind machines. The study also estimated the cost of wind-based electricity (COE, US$/kWh) by using different capacities of commercial WECS. It was found that the COE per kWh is 0.045 US$/kWh for 150 kW wind machine (at 50 m hub-height) whereas COE was 0.039 US$/kWh for 600 kW wind machine (at 50 m hub-height). The study also dealt with wind turbine characteristics (such as capacity factor and availability factor). These characteristics are important indicators of wind turbine performance evaluation.