Relative merits of load following reserves & energy storage market integration towards power system imbalances

Traditionally, power system balancing operations consist of three consecutive control techniques, namely security-constrained unit commitment (SCUC), security-constrained economic dispatch (SCED), and automatic generation control (AGC). Each of these have their corresponding type of operating reserves. Similarly, energy storage resources (ESRs) may be integrated as energy, load following, or regulation resources. A review of the existing literature shows that most ESR integration studies are focused on a single control function. In contrast, recent work on renewable energy integration has employed the concept of enterprise control where the multiple layers of balancing operations have been integrated into a single model. This paper now uses such an enterprise control model to demonstrate the relative merits of load following reserves and energy storage integrated into the resource scheduling and balancing action layers. The results show that load following reserves and energy storage resources mitigate imbalances in fundamentally different ways. The latter becomes an increasingly effective balancing resource for high net-load variability and small day-ahead market time step.