Techno-economic feasible region of electrochemical energy storage participating in the day-ahead electricity market trading

As electrochemical energy storage (EES) becomes increasingly prevalent in electricity markets, accurately assessing their techno-economic performance is crucial. This paper introduces the novel concept of the technoeconomic feasible region (TEFR) for EES participation in electricity markets, providing a new analytical framework for optimizing EES market strategies. The main contributions are: 1) A bilevel game-theoretic model is developed for both independent energy storage (IES) and wind-storage system (WSS) to capture the complex interactions between EES and the independent system operator (ISO); 2) A systematic method is proposed for determining TEFR, and geometric metrics including surface area, normalized volume-to-surface area ratio, and roundness are introduced to quantify TEFR characteristics. Based on the IEEE 24-bus system analysis, it is found that WSS exhibits 10-15 % larger operational boundaries than IES, but with similar utilization efficiency; 3) Sensitivity analyses reveal that charge/discharge power has the most significant impact on TEFR characteristics, with the normalized volume-to-surface area ratio increasing by 10.8 % and roundness rising by 124 % when power increases from 28 MW to 30 MW. This study provides an important theoretical foundation for optimizing EES design and market participation strategies.