Harnessing the Flexibility of Demand-side Resources

Flexibility is of prime importance for current and future power systems with increasing grid integration of variable renewables. Insufficient flexibility can result in high renewable energy curtailment levels, excessive intra-hour plant cycling and/or frequency stability concerns. Addressing all these issues simultaneously could result in more efficient asset utilization—demand response is one potential option. The challenge, however, is to ensure a suitable adaptation of the flexible demand response to evolving system requirements across multiple operational time scales. To this end, this paper presents a multi-level, multi-time scale methodology for simultaneous provision of multiple system services to alleviate the aforementioned issues using a single demand-side resource. Based on effective aggregation/disaggregation, the proposed methodology is implemented for residential thermal energy storage using different temporal and control levels, while importantly, still guaranteeing satisfaction of thermal comfort requirements of individual dwellings. Assessment of the proposed methodology on a test system reveals that it can significantly improve the system performance at different temporal levels by bridging the gap between individual load control and system-wide flexibility requirement.