The application of energy storage within transmission and distribution grids as non-wire alternative solutions (NWS) is hindered by the lack of readily available analysis tools, standardized planning processes, and practical know-how. This Element provides a theoretical basis along with examples and real-world case studies to guide grid planners in the siting, sizing, and lifetime techno-economic evaluation of storage systems. Many applications are illustrated including feeder peak shaving, feeder reliability improvements, transmission reliability, transmission congestion relief, and renewable integration. Three case studies, based on the author's consulting experience, illustrate the versatility of the analysis methods and provide a guide to grid planners while tackling real world problems.