In the overall process of utilizing wind power, two essential components of technical data, i.e. one related to the engineering or performance characteristics of commercially available wind turbine generators, and the other related to the availability of wind resources, are needed. The performance of wind energy conversion systems (WECs) depends upon subsystems like wind turbine (aerodynamic), gears (mechanical), and generator (electrical). The availability of wind resources is governed by the climatic conditions of the region, for which the wind survey is extremely important to exploit wind energy. In this paper, design aspects, such as factors affecting wind power, siting requirements for WECs, problems related with grid connections, classification of wind electric generation schemes, criteria for selection of equipment for WECs, choice of generators, three basic design philosophies, main considerations in wind turbine design, choice between two and three blade rotors, weight and size considerations and environmental aspects related with WECs have been presented.