This document is a test guideline for the purpose of characterising the efficiency, standby consumption and controller efficiency of stationary battery storage systems. Department of Energy (DOE) Federal Energy Management Program (FEMP) and others can employ to evaluate performance of deployed BESS or solar photovoltaic (PV) +BESS systems. The. . Getting familiar with the basic specs of energy storage systems helps make them work better in practice. Energy capacity, usually shown in kilowatt hours (kWh), tells us just how much juice a system can hold inside. It provides info following system functions:BESS as backupOffsetting peak loadsZero exportThe battery in the BE S is charged either from the PV system or the grid tem, temperature control system and. . acterization and evaluation of thermal energy storage (TES) systems. Therefore, the main goal of IEA-ECES Annex 30 is to determine the suitability of a TES system in a final application, either from the retrofit approach (modification of existing p ocesses) or the greenfield approach (modification. . The optimal configuration capacity of photovoltaic and energy storage depends on several factors such as time-of-use electricity price, consumer demand for electricity, cost of photovoltaic and energy storage, and the local annual solar radiation.