Role and Value of Pumped Storage Units in an Ancillary Services Market for Isolated Power Systems—Simulation in the Taiwan Power System

For isolated power systems, an efficient and effective ancillary services market is one of the most important tools to ensure the system security and service quality. It is recognized that pumped storage units can play a unique role in the operation of isolated power systems. As part of the introduction of the ancillary services for Taiwan, a study was performed to identify the role and value of pumped storage units in the fast-response reserve (FRR). This paper analyzes the actual dispatching schedules of pumped storage units in the Taiwan Power System (TPS) to provide FRR when system was operated under seriously insufficient conditions for the year 2004. The results are used to quantify the value of pumped storage units in the ancillary services. Since the dispatching schedules of pumped storage units determined the cost of FRR in the TPS, the actual operating experience of pumped storage units studied in this paper can be used to evaluate the impact on the system security and to further define the role of pumped storage units in the ancillary services market.