Review of Optimal Energy Management Applied on Ice Thermal Energy Storage for an Air Conditioning System in Commercial Buildings

This paper investigates the cost saving potentials of energy for cooling loads in the commercial buildings using a realtime optimization control strategy capable of efficiently managing an operation of the (ITES) Ice Thermal Energy Storage for building's HVAC (Heating, Ventilation and Air Conditioning) system. The ITES is a Thermal Energy Storage (TES) system, which reduces the cost of energy in HVAC systems. Reduction in the cost of energy is achieved by shifting the cooling load from the peak and standard periods to the off-peak periods, with the aid of stored ice, which is produced when the energy cost is affordable and discharging when the cooling demand is high, particularly at expensive tariff rates. The challenge is that, most of the existing ITES systems, particularly in South Africa, are not optimal in operation. The conventional system should be optimally controlled to a higher accuracy. Based on investigations, a preferred accuracy could be achieved, with some comparisons and validations of results, by utilization of real-time control and optimisation tools, such as Fuzzy logic, Neural network, Closed-loop and Model Predictive Control (MPC). Effective utilization of ITES allows a further advantage in the management of the off-peak tariffs and consumers' demands, in accordance with the Time of Use (TOU) and maximum demand. Climate changes, installation, payback costs and other objective functions are required as additional options to the improved utilisation and design of the ITES system. The findings from the review and analysis of technologies and approaches to optimisation should benefit improvisation of the ITES in future applications.