Electricity and reserve market bidding strategy including sizing evaluation and a novel renewable complementarity-based centralized control
A. González Garrido, H. Gaztañaga, A. Saez de Ibarra, A. Milo, P. Eguia
On the path to increase the renewable penetration level in power systems, energy storage systems are increasingly considered a key flexible technology to support renewable operation. Despite the reduction of ESS capital costs and their progressive inclusion in electricity markets, the major challenge is to develop new cost-effective business cases for renewable sources and electrical storage devices, which operate in aggregation and participate reliably in electricity markets as well as provide additional ancillary services. The main goal of the paper is to propose a centralized energy management strategy focused on portfolio scheme maximization including favorable market opportunities, such as continuous intraday market and frequency restoration reserve. Besides conventional cost function maximization, the consideration of technical aspects in the optimization allows high reliability of reserve requirements and reduction of energy imbalances. The main research contribution is the novel centralized supervisory control in real-time operation compared to a decentralized approach. This centralized control re-allocates reserve energy to achieve full market compliance and takes advantage of renewable complementarity to apply an innovative state of charge technique which minimizes battery stress and enhances their lifetimes. Therefore, in addition to the optimal storage sizing analysis, storage capacity fade and expected lifetime are accurately estimated according to the operation by means of experimental cycling and calendar aging models to calculate investment and replacement costs. Finally, a techno-economic evaluation of the cost-effectiveness of storage integration is provided.