Experimental Analysis of Efficiencies of a Large Scale Energy Storage System

This paper documents the investigation into determining the round trip energy efficiency of a 2MW Lithium-titanate battery energy storage system based in Willenhall (UK). This research covers the battery and overall system efficiency as well as an assessment of the auxiliary power consumption of the system. The results of this analysis can be used to run the system at its optimal operating conditions to achieve maximum efficiency and minimal losses. Consequently, economic benefits can be reaped by running at higher efficiencies and strategising when to buy and sell (charge and discharge) energy while providing grid services.