Before revision:  Finally, the numerical and empirical analysis suggests that the high cycle cost for battery  is still the main barrier for grid-connected battery systems , and the flexibility offered by such systems would be currently the most promising comparative advantage for this novel technology. Additionally, a correct recognition of the barriers and advantages by all the stakeholders, including the system /  market operator, policy maker, investor, and project manager, is the key factor to promote battery storage technologies in grid-connected applications.
After revision:  Finally, the numerical and empirical analysis suggests that the high cycle cost for battery is still the main barrier for grid-connected battery systems . In Spain, for energy arbitrage within the day-ahead market, it is required that the battery wear cost decreases to 15 Euro / market operator, policy maker, investor, and project manager, is the key factor to promote battery storage technologies in grid-connected applications.