Battery Lifetime Prediction Using Cycle Estimation in De-dedieselization Program

The De-dieselization Program has been launched by PT. PLN (Persero) as one of the expedient approaches towards attaining the goal of a 23% share of renewable energy in the national energy blend in 2025. The project comprises multiple and widely distributed standalone microgrids scattered across remote regions in Indonesia. Typically, the arrangement of the system at each location is small and isolated systems that are not interconnected with the interconnection grid. Each microgrid consists of PV (Photovoltaic) and BESS (Battery Energy Storage System) designed to supply energy to the loads. These facilities are also expected to operate in a hybrid mode with the existing diesel generators. Many microgrid facilities in Indonesia have used BESS as an energy storage technology. The BESS lifespan can be reduced due to the fluctuation in output power of a microgrid caused by renewable energy generation sources such as PV. Frequent replacement of the BESS can substantially increase the operating costs of a project, given that it has a limited lifespan and is the costliest component of a microgrid. The cycle counting method to assess BESS lifespan using properties in PLEXOS has been conducted on LiFePO4, a li-ion battery. According to the conducted study, the accumulation of battery cycles is significantly influenced by the SOC condition and battery capacity. The impact of battery capacity on system parameters, such as unserved energy and generation capacity curtailed, is also demonstrated in this report. It is found that cycle counting is a practical method to estimate battery age.