Given the growing shares of renewable energy sources in the grids, the interest in energy storage systems has increased. The role of pumped hydro energy storage systems as flexible solutions for managing peak and off-peak prices from nuclear and fossil power plants in previous systems is now revitalized in the liberalized systems, with a volatile generation of wind and solar energy. Thus, understanding of the patterns behind the economics of energy storage is crucial for the further integration of energy storage in the grids. In this paper, the factors that impact the economic viability of energy storage in electricity markets are analyzed. The method of approach used in this study considers the electricity market price distribution, full load hours, the total costs of energy storage, and linear regression analysis. Using revenues from arbitraging a 10-megawatt (MW) pumped hydro storage system in the Western Balkans, resulting from the electricity market price distribution and the analysis of the total costs of storage, an econometric model is created. This model shows the impacting factors of energy storage development in the context of the rising renewables sector. Research shows that the previous hypothesis about the integration of energy storage systems in proportion to the increase in shares of renewables in the grids is incorrect. There is a significant correlation between energy storage revenues, the dependent variable, and the independent variables of hydro, wind, and solar generation. The conducted analysis indicates the future arbitraging opportunities of pumped hydro energy storage systems and provides useful insights for energy storage investors and policymakers. During the transitional period, until the deployment of renewables changes the effects of fossil power plants, energy storage price arbitrage is profitable and desirable for 500, 1000, and 2000 full load hours in the Western Balkan region. Despite the need for flexibility, with more renewables in the grids, large-scale energy storage systems will not be economically viable in the long run because of “revenue cannibalization”.

With the expansion of renewables in the electricity markets, research on electricity storage economics is needed for a better understanding of the utilization of these systems and for improving the performance of intermittent variable generation. Collected up-to-date research of electricity storage systems published in a wide range of articles with high impact factors gives a comprehensive review of the current studies regarding all relevant parameters for storage utilization in the electricity markets. Valuable research of technical characteristics from the literature is broadened with the electricity storage analyses from an economic point-of-view. Analysis of selected technologies, considering different perspectives such as their profitability, technical maturity, and environmental aspect, is a valuable addition to the previous research on electricity storage systems. Comparing conducted analysis with the selected literature, electricity storage technologies are analyzed concerning their viability in the electricity markets. Given the current outlook of the electricity market, the main problems for storage's wider integration are still energy storage costs. These can be overcome with different applications of energy storage systems, integration of new market players, or a combination of storage technologies along with the implementation of new energy policies for storage.