Optimal Dispatch of Battery Energy Storage Considering Cycling and Calendar Ageing

The growing share of renewable energy sources in the energy mix and the liberalization of electricity markets drastically affected the operation of electricity generators. This transition from fossil fuel-based energy systems to renewable ones will significantly change the energy market, giving important opportunities for energy storage systems. In the next years, a large amount of storage capacity is foreseen to be integrated into the electricity grids to shave the demand peaks, mitigate price volatility, and provide services to the grid. In such a situation, to properly manage these crucial technologies, and thus guarantee the economic viability of the operation, it is essential to properly optimize the dispatch and define the best scheduling. This paper considers Battery Energy Storage (BES) to study the problem of dispatch optimization of storage technologies. The complete model of BES is developed, considering especially the effect of DoD (Deep of Discharge) on the total number of cycles, that influence significantly the degradation, and the influence of the current-rate on the total efficiency, due to the effects of losses for the Joule effect. The implemented optimization is based on a Mixed Integer Linear Programming (MILP) approach, the discretization of the state of charge (SoC), and the continuous update of rated capacity until the maximum admissible fade is reached. Different scenarios are compared showing how the effectiveness of the proposed approach at maximizing the net operational profits or minimizing the loss depending on the profitability of markets.