The book presents the basics ideas about wind energy and the continuous development in the field. It reviews about the available VAWT/HAWT, airfoil theory, and Betz Law. Further, it explains about the determination of various parameters associated with wind energy like: pressure distribution, co-efficient of pressure, wind power, lift, drag etc. for a symmetrical as well as for non-symmetrical airfoil cross-section. The analysis of pressure distribution and pressure coefficients distribution has also been presented for various airfoils to select one for VAWT and the velocity profile of wind speed over blade cross-section has also been presented. In the last, an attempt has been made to present the scenario of wind energy all over the world by taking consideration of various reports available.