Effects of ‘invisible’ energy storage on power system operations

Abstract

Together with rising renewable energy generation, energy storage installation is also growing, both at utility scale as well as behind the metre. Behind-the-metre energy storage systems (ESS) are netted out with load and is not dispatchable by the power system operators, making them invisible. While works in the literature have investigated the benefits of coordinated ESS, the impact of non-dispatchable and invisible ESS on the transmission system remains unknown. To shed light on the topic, two levels of optimisation are formulated in this work: the upper minimises generation cost while the lower minimises customers’ electricity bill with different electricity tariffs. Through simulations at various ESS and photovoltaic (PV) penetration on IEEE reliability test system with real weather data, invisible ESS have been found to increase the power system ramping requirement, make the net demand and electricity price more volatile, as well as increase the cost of power system operations for the test system studied. In light of these findings, power system operators should analyse the impacts of invisible ESS in their respective networks to pre-emptively mitigate the possible detrimental effects.