Role of hybrid (wind plus diesel) power systems in meeting commercial loads

The utilization of energy from renewable sources, Such as wind, is becoming increasingly attractive and is being widely used for the substitution of oil-produced energy, and eventually to minimize atmospheric degradation. Literature shows that commercial/residential buildings in Saudi Arabia consume an estimated 10-40% of the total electric energy generated. In the present study, hourly mean wind-speed data for the period 1986-1997 recorded at the solar radiation and meteorological monitoring station, Dhahran (26degrees 32' N, 50degrees 13' E), Saudi Arabia, have been analyzed to investigate/examine the role of hybrid (wind + diesel) energy conversion systems in meeting the load requirements of a typical commercial building (with annual electrical energy demand of 620,000 kWh). The monthly average wind speeds for Dhahran range from 4.1 to 6.4 m/s. The hybrid systems considered in the present analysis consist of different combinations of the commercial 10 kW wind energy conversion systems (WECS), supplemented with battery storage unit and diesel back-up. The study shows that with thirty 10 kW WECS and 3 days of battery storage, the diesel back-up system has to provide 19% of the load demand. However, in the absence of battery storage, about 40% of the load needs to be provided by the diesel system. (C) 2003 Elsevier Ltd. All rights reserved.