Energy storage in an open electricity market with contribution to transmission congestion relief

A real-time optimal dispatch (RTOD) algorithm is proposed in this paper by formulating a mixed integer linear programming (MILP) problem to determine dispatch quantities for a privately-owned energy storage system (ESS) operating in an open electricity market. A new mechanism is proposed and implemented in the optimization problem based on historical and forecasted information available to the ESS to prepare the ESS for possible congestion relief external commands. The performance of the RTOD is evaluated through studying of ESS operation for different possible cases, and the results are discussed. As an example of utility-scale ESSs, a compressed air energy storage (CAES) is used to evaluate the performance of the proposed technique. The investigation results reveal that the external congestion relief commands should be forecasted and incorporated as part of the RTOD to achieve optimal performance and higher financial benefits.