Robust unit commitment considering reserve from grid-scale energy storage

Due to the growing of installed wind capacity, power system faces security and stability problems, and more reserve is needed to settle the uncertainty of wind generation. An energy storage system (ESS) is a kind of device that can add flexibility in power system operation, providing reserve and other auxiliary services. To manage reserve from ESS and estimate its benefits in wind generation integration, this paper investigated the unit commitment problem considering the spinning reserve from ESS and the influence from wind power fluctuation. The spinning reserve from conventional generators and ESS is used to hedge the uncertainty of wind generation. The unit commitment problem is formulated as a mixed integer problem using two-stage robust optimization to account for wind uncertainties, and the problem is solved by a column-and-constraint generation (C&CG) method. Comparative case studies show the effectiveness of the method, and the utilization of energy storage in providing spinning reserve can reduce the total cost by reducing the number of operated units, which are used to operate to hedge wind uncertainty.