Optimal Energy Storage Systems for Long Charge/Discharge Duration

The interest for long-term energy storage in electrical grid provided with renewable energy sources is presently growing, because of the wide range of service that such systems can offer [1,2]. Although the choice of optimal duration of the charge / discharge cycles of energy storage systems for stationary applications is still an open question, among the different energy storage technologies available at a high readiness level (TRL), a few fit particularly well this kind of services [3,4]. Depending on the application and the market in which the energy storage systems are applied, the optimal duration can have different values and call for different technologies. Among electrochemical energy storage systems Vanadium Redox Flow Batteries (VRFBs) are emerging as a very promising solution for long-term stationary applications [5]. In order to find an optimal duration value for applications, the development of a physical-economic model becomes essential. Indeed, the optimal duration of energy storage systems not only depends on the technical features of each energy storage device (e.g. life cycle, self-discharge, ecc...), but also on the specific services required by the market. VRFBs devices which may be very expensive for a specific market, could be a competitive solution for a different one. The purpose of this work is to size the optimal duration of VRFB system according to the specific applications and the reference market. Reference Wu Y, Liu Z, Liu J, Xiao H, Li, R, Zhang L, Optimal battery capacity of grid-connected PV-battery systems considering battery degradation, Renewable Energy, 2022,181:10-23. DOI: 1016/j.renene.2021.09.036. Simoglou CK, Biskas PN, Marneris IG, Roumkos CG, Long-term electricity procurement portfolio optimization, Electric Power Systems Research, 2022, 202:107582. DOI: 1016/j.epsr.2021.107582 Alotto P, Guarnieri M, Moro F, Redox Flow Batteries for the storage of renewable energy: a review, Renewable & Sustainable Energy Reviews, 2014,29:325-335. DOI: 1016/j.rser.2013.08.001. Ibrahim H, Ilinca A, Perron J, Energy storage systems-Characteristics and comparisons, Renewable and Sustainable Energy Reviews, 2008,12,5:1221-1250. DOI:10.1016/j.rser.2007.01.023 Guarnieri M, Mattavelli P, Petrone G, Spagnuolo G, Vanadium Redox Flow Batteries: Potentials and Challenges of an Emerging Storage Technology, IEEE Industrial Electronics Magazine, 2016,10,4:20-31. DOI: 1109/MIE.2016.2611760. Figure 1