Scheduling of cool storage using non-linear programming techniques

Thermal energy storage for space cooling is a load management technology that achieves load shifting by creating and storing cooling capacity during off-peak hours in anticipation of peak period loading. The charge and discharge process in a cool energy storage system is typically a 24-hour cycle. In this paper, an optimal controller for this process is designed that minimizes the operating costs of the storage facility. A 24-hour load-forecast model is developed to achieve dynamic system response to the variations in the ambient weather conditions. Hourly building cooling loads are predicted over the 24-hour horizon to schedule adequate charging of storage to meet peak-period loads. The degradation of performance of the optimal control algorithm attributable to the lack of perfect foresight of weather conditions and associated building loads is analyzed via a case study. A safety margin is also calculated and presented to compensate for same