Thermal energy storage for industrial thermal loads and electricity demand side management

Abstract

Thermal energy storage offers a solution to mitigate the intermittency of electricity generation in a grid powered by renewable energy and an opportunity to arbitrage on the temporal variability in the cost of the grid supplied energy. This study investigates the potential of a thermal energy storage system used for thermal load and electricity demand management at the industrial scale. A latent heat thermal energy storage system in conjunction with an advanced control and forecast algorithm have been integrated into an existing industrial food processing plant. This demonstration system also incorporates electricity from onsite PV and the grid to power the refrigeration system. The control and forecast code provide a schedule to charge the thermal energy storage from the grid during low or negative prices; otherwise, it instructs to charge from solar PV or discharge to cover the refrigeration load. The data collected from the demonstration system clearly showed the role of the integrated system in demand side management leading to electricity cost reduction during the ten months of operation. The net estimated electricity cost savings was 10,435 AUD in ten months, while doubling the capacity of thermal energy storage could save about 48,700 AUD per annum. Data analysis of energy demand acquired from all the modules of the plant provided valuable insight into further optimization of the control code for higher realization of its potential in the reduction of electricity demand charges. Moreover, such a control system combined with thermal energy storage can be used for the management of any variable load and renewable energy sources.