Economic impact of medium-scale battery storage systems in presence of flexible electricity tariffs for end-user applications

This article addresses the question if it is cost-effective to use medium-scale battery storage systems for time-of-use (TMO) energy cost applications at a consumer level, assuming flexible electricity tariffs in the Italian electricity market. TMO application allows customers to reduce their electricity bill charging the storage when off-peak time periods are applied and discharge it during on-peak periods, when electricity energy prices are high. The analysis is carried out taking into account three different electrochemical storage technologies. The economical comparison shows that, at the current costs of storage technologies and at the electricity tariffs currently offered in Italy, the use of battery systems for TMO energy cost applications is not economically advantageous for a medium-scale public institution facility. However, the aggregation of different benefits for the same storage technology, such as voltage support, deferral of investment in T&D network upgrades, reducing T&D losses and so on could modify this assumption.