The characteristics of wind energy generation are different from those of conventional energy sources. The uncertainty and variability of wind power creates considerable challenges in planning and operating an electric power system while maintaining an acceptable level of reliability. The contributions of wind energy sources to the reliability of the overall power system depend on many factors, such as the strength of the wind resource, the point of wind integration in the power grid, the generation system configuration, and the topology of the transmission network, etc. Wind energy sources are typically installed at locations with strong wind regimes. Composite generation and transmission system reliability studies can be conducted to identify the optimal network locations to inject new generation that will provide maximum reliability benefit to the system. The wind regime at an optimal bus location may, however, be relatively low. This paper illustrates the reliability benefits of wind power from both resource strength and the location points of view, and the impact of wind power diversification on the bulk system reliability.