A high peak demand causes the escalating cost of electricity costs for both the utility and end-users. This paper investigates the challenges raised by the high peak demand and the state-of-The-Art technologies adopted to reduce the peak demand. The peak shaving technologies can be categorized into four groups. The first category is peaking power plants which include the open-cycle gas turbine (OCGT) power plants and hydroelectric power plants. The second category is the energy storage system (ESS) comprising of the pump hydro storage (PHS), compressed air energy storage (CAES), battery energy storage (BES), flywheel energy storage, thermal energy storage (TES) and hydrogen fuel cell. The third category is the hybrid renewable energy-storage system (HREES) that combines the renewable energy (RE) and energy storage system. The fourth category is the demand-side management (DSM. The advantages and shortfalls of these technologies are highlighted in this paper.