Impact of grid-scale energy storage systems on energy and frequency regulation Colombian markets

This article proposes a co-optimization model that allows evaluating the simultaneous participation of energy storage systems (ESS) in arbitrage applications, secondary frequency regulation, and transmission investment deferral. The model considers the ESS degradation through an upper-piecewise linear approximation; constraints related to primary frequency energy reserve are also included in the model. The formulation is evaluated using historical data from the Colombian wholesale energy market. Eight case studies corresponding to the possible combinations of ESS participation in the three applications are analyzed. Subsequently, a financial evaluation is carried out for each case study, both from the system and the investor's point of view. The results show that the exclusive use of ESS to provide arbitrage is not economically viable in Colombia, while simultaneously providing secondary frequency regulation and restriction relief services is profitable, both for the system and for an investor agent.