This paper describes in detail 10 key applications which can support the entire chain of the electrical system, from generation and system-level applications through T&D system applications to end-user applications. Included are: wholesale energy services, renewables integration, large and small storage and transportable systems for T&D grid support, ESCO aggregated systems, commercial and industrial power quality and reliability, commercial and industrial energy management, home energy management, and home back-up storage. Capturing multiple benefits—including transmission and distribution (T&D) deferral, local or system capacity, and frequency regulation—was found to be key for high-value applications and for supporting the business case for energy storage. Applications that achieve the highest revenues do so by aggregating several benefits across multiple categories. An analytic framework is presented to estimate the benefits and life-cycle costs, and help guide and shape the economic treatment of energy storage systems. Because energy storage systems have multi-functional characteristics, which complicates rules for ownership and operation among various stakeholders, policy challenges were identified that need to be resolved to realize the true potential of storage assets.