Levelized Cost of Storage for Hybrid Energy Storage Systems with Fast Response Capabilities for Energy Arbitrage and Fast Frequency Response

As modern power system shifts to renewable energy sources from conventional synchronous generators, the power system’s reliability and stability are compromised. To ensure that the power system remains stable and efficient despite the challenges posed by transitioning to renewable energy sources, many system operators are introducing new ancillary services. Energy storage systems can provide some of these ancillary services, but the potential investors have to decide which technology is the most appealing in terms of revenue, installing costs and maintenance & operations costs, while complying with the system operator’s technical requirements. This work utilizes the levelized cost of storage to investigate if a hybrid energy storage with battery and short-term energy storage with small capacity is a more attractive investment when compared to single battery energy storage and short-term energy storage. Three hybrid energy storage configurations are considered, the battery/superconducting energy storage, battery/supercapacitor and battery/flywheel energy storage. In the levelized cost of storage formula the ancillary service of Ireland’s fast frequency response and the participation in the balancing market of Ireland for energy arbitrage are also included. The results revealed that the configuration battery/supercapacitor has the lowest levelized cost of storage without/with payment rate reduction among the single energy storage and hybrid energy storage.