Dynamic battery operational cost modeling for energy dispatch

Battery Energy Storage Systems (BESS) have gained extensive application in both grid and microgrid applications. One major type of BESS are electrochemical batteries such as Lead-Acid and Lithium-Ion batteries which have limited number of lifecycles. The common way of considering their operation cost is using a constant value such as LCOE (levelized cost of energy). However, as shown herein, given the same amount of energy output, the battery lifecycle degradation, and thus the degradation cost, can vary at different operation conditions (voltage, current, power, state of charge (SOC)) by up to 6 times. Herein a model for the dynamic battery operation cost as a function of its dispatch power and SOC is developed. The model also considers the dependency of battery voltage on its current and SOC, which equivalently takes into account the dependency of its conversion efficiency on its power and SOC. Preliminary simulations demonstrate that using the proposed model, instead of the LCOE, for Microgrid operation optimization microgrid operation cost is lower by up to 12%.