The potential of thermostatically controlled appliances for intra-hour energy storage applications

This paper investigates the potential of providing a variety of energy storage services by directly control the thermostatically controlled appliances (TCAs) from a centralized controller. Dispatch algorithms for the controller to arrange the turn-on and turn-off time and duration of individual TCAs are presented. The control goal is to operate each TCA within the customer-desired temperature range and maintain the TCA load diversity, and make the aggregated TCA load at the target load level. Methods to minimize the communication needs by reducing the monitoring and control data flows between the central controller and the end devices are also discussed. A thousand space heating units are modeled to demonstrate the control algorithms to provide load shifting and load balancing services for a period of 24 hours. The results demonstrate that the energy and ancillary services provided by the TCA loads meet the performance requirements and can become a major source of revenue for load-serving entities where the two-way communication smart grid infrastructure enables direct load control over the TCA loads.