Economic feasibility of medium-term energy storage for intermittent power producer

This paper examines the economic feasibility of alternative energy storage systems for medium-term applications, with a specific focus on Energy Storage Systems (ESS) utilized for day-ahead and intraday arbitrage and the integration of renewable energy. The study uses a mixed-methods approach to evaluate five different technologies: Redox Flow Batteries (RFB), Adiabatic Compressed Air Energy Storage (A-CAES), Liquid Air Energy Storage (LAES), Thermal Energy Storage (TES), and lithium-ion (LI-ON) batteries. This evaluation is done using mixed-integer linear programming to model annual revenues at different trading success rates to present a scenario-based analysis and economic parameters such as net present value, internal rate of return, levelized cost of storage, and total cash flow. The findings suggest that all technologies perform well in intraday arbitrage, with LI-ON technology generating the maximum income and A-CAES technology having the lowest levelized cost of storage. On the other hand, day-ahead arbitrage and renewable integration scenarios show less profitability, as they need substantial price changes to provide positive returns. RFB and A-CAES are emerging as viable alternatives to conventional LI-ON batteries. RFB has the potential to generate up to 87 % of the revenue that LI-ON batteries can generate, while A-CAES offers cost benefits that are comparable to LI-ON batteries. Nevertheless, LAES repeatedly demonstrates subpar financial performance, emphasizing the necessity for cost reductions. The findings highlight the need to employ various storage technologies to improve the integration of renewable energy. • All assessed storage systems show positive value generation in intraday arbitrage. • Neither energy storage systems were economically viable for day-ahead trading. • Overall performance improved when optimization period extended from day to a week. • Redox flow batteries and CAES are feasible alternatives to Li-ion batteries, • Thermal storage and LAES require ancillary revenue to be economically feasible.