Impacts of Energy Storage on Short Term Operation Planning Under Centralized Spot Markets

Energy Storage Systems (ESS) are an alternative to provide flexibility in power system operation. ESS have been foreseen as crucial technologies to facilitate the transition to a low-carbon energy matrix that integrates higher level of renewable variable energy resources. In this paper, the integration of grid-scale ESS in short term operational planning under a centralized cost-based electricity market is analyzed through an adapted stochastic unit commitment formulation to provide energy arbitrage, primary or/and secondary reserve. Several computational simulations are performed in a realistic study case to discuss techno-economic effects of ESS integration in detail. Results obtained show that value of storage is increased when ESS jointly provide different services. Additionally, ESS enable greater participation of renewables into generation mix, while reducing impacts on flexible power plants. Influence of ESS in marginal price signals is also discussed. The undertaken discussion provides insight information for agents in liberalized markets.