Shifts in consumer behaviors in the power sector coupled with social and environmental policies have created a higher demand for reliable power and a desire to generate that power from less reliable sources. To bridge the gap in reliability between the power that is generated and the power that is consumed, it is up to the utility to deploy new strategies to face these challenges that have been created. One technology that can aid utilities in facing these challenges is a lithium-ion battery energy storage system (BESS). This thesis will present four common applications for BESS use in the power system which include load shifting, voltage support, back-up power supply, and frequency regulation. The economic feasibility of the use of this system will be presented by comparing the costs of traditional solutions to the cost of a lithium-ion BESS to satisfy the needs of the different applications. The cost comparison shows the potential benefits of deploying this technology. Market trends for lithium-ion battery costs will also be presented to demonstrate the increased potential benefit of the technology.