This centralized load controller is used to provide continuous regulation reserves (CRRs) using thermostatically controlled appliances (TCAs). A temperature-priority-list method is developed to dispatch TCA loads to meet CRR requirements while maintaining customer-desired indoor temperatures and the load diversity. The key steps are to group and prioritize TCA resources based on a forecaster prediction of the HVAC behaviors for the next time step. Before the controller starts the dispatch algorithm, all the controllable HVAC units are first divided into two groups based on their forecasted on/off status. For example, if space heating units are used, the units in the “on” group are prioritized in descending order based on their room temperatures, i.e., if the room temperature is closer to the upper thermostat setting T+, the unit is at the top of the queue to be turned off. The units in the “off” group are prioritized in ascending order based on their room temperatures, i.e., if the room temperature is closer to the lower thermostat setting , the unit is at the top of the queue to be turned on. The HVAC units that are “on” under direct load control will switch off immediately when they receive an “off” signal from the central controller, and vice versa. The forecaster is used to estimate room temperatures of the HVAC units for the next time step, determine the on/off status of the HVAC units, and create two priority (turn-on and turn-off) lists for the two groups of HVAC units. The forecasts, , can be tuned and corrected based on actual measurement, , collected from HVAC units every 15 minutes. The forecaster can use a simplified HVAC thermal model as described in Section II.A. An update process can be seen in Fig. 10. This forecast-and-update process will reduce the amount of data traffic from each controlled HVAC unit to the central controller. 1000 HVAC units in their heating modes can be controlled by the central controller to provide a ±1-MW CRRs 24 hours a day. The controller is robust to forecasting errors, minimum HVAC turn-off times, response delays, and consumer overrides.