Operation of Energy Storage in Power Systems with High Wind Penetration

Energy storage has the potential to increase the flexibility of electric power systems, allowing them to increase wind energy penetration to higher levels than currently possible. However, there are questions about its economic viability, which directly depends on how storage is operated and the services it provides to the power system. These services can be classified according to the time frame in which they are offered, such as day-ahead, load following and regulation. Yet current storage scheduling methods focus on providing services in only one of these time frames, generally day-ahead. This dissertation proposes a methodology to schedule energy storage optimally across multiple operational time frames in power systems with high wind penetration in order to achieve minimum system operating costs. This methodology uses sequential centralized optimizations formulated using Mixed Integer Programming (MIP). A case study with 10 thermal generators and one near-ideal energy storage unit demonstrates the usefulness of the methodology. Simulation results for multiple wind energy penetration levels show that the difference in generation cost savings between a coupled energy storage operation approach and a base-load energy storage operation approach increases as wind energy penetration increases because of the added flexibility available to cope with intra-hour wind fluctuations. Other impacts of adding energy storage to a power system such are also analyzed.