Impact of operational scheduling of pumped storage power plant considering excess energy and reduction of fuel cost on power supply reliability in a power system with a large penetration of photovoltaic generations

In recent years, a substantial amount of photovoltaic (PV) generations have been installed in power systems. However, the power output from the PV is random and intermittent in nature. As a result, the PV generation poses many challenges to system operation. PV generates electricity only in the daytime regardless of power demand. When the daytime power demand is small and PV generation is large, severe imbalance in power demand and supply may occur in the power systems. To mitigate the power imbalance, we propose that pumped storage power plant (PSPP) is used to solve the problem. Usually the PSPP is operated in generator mode in the daytime and in pump mode in the nighttime. However if the power imbalances due to the installation of PV is also to be handled by PSPP then the operating patterns of PSPP have to be modified. Such modification in the operating pattern of PSPP could introduce reliability concerns related to the operation of power systems. Therefore we need to study impact of the operational patterns of PSPP to solve the problems associated with excess power produced by PV on the power supply reliability. In this paper a new method for the effective operating pattern for PSPP taking into consideration the fuel cost and the impact of excess power on the reliability of system operation is presented.