Optimization of electric energy consumption operating costs in cooling technique by establishing a remote central control system, exploiting thermal capacity and load shifting

Shopping centers consume a large amount of electric energy and it is generally confirmed their cooling systems are of highest share. This paper investigates and proposes an integrated approach of how to achieve and enlarge economic savings in refrigeration systems by exploiting thermal capacity of the stored goods. Goods are able to store energy in the form of cold and later reactivate it, which enables time shifting. In terms of costs, taking into account the daily electric price fluctuations the optimization is the most efficient when time period of storing the energy coincides with the time period of the lowest energy price in a day and vice versa, when time period of reactivation of the previously stored energy starts when the electric energy price jumps to its highest value. The paper presents an optimization algorithm that is to be implemented on a central control management system established to control the operation of each shopping center and of each individual cooling unit from which it collects parameters and data that is further on used to calculate the following actions. The scheme of such system and an optimization algorithm are suggested. Actual values are used in simulation, thermal losses are taken into account and simulation results indicate a significant 9.34 % decrease in electric energy consumption costs.