Abstract
In remote off-grid areas, the mining industry often generates substantial carbon emissions by heavily relying on diesel fuel for electricity, heating, and cooling. To address this environmental challenge, there is a growing interest in exploring eco-friendly energy alternatives. One promising solution is integrating renewables into the energy mix to achieve full decarbonization. A full decarbonization scheme, however, relies on the total reliance on renewables which is not feasible due to the intermittency of such clean power. To address this issue, this study explores the use of high-temperature rock-based thermal energy storage (RTES) system touted for its simplicity, affordability, and potential for high energy densities. Thermo-physical characteristics of magnetite as the storage medium is developed, and a Computational Fluid Dynamics (CFD) model, incorporating the Local Thermal Non-Equilibrium (LTNE) assumption, simulates convective heat exchange between the air and magnetite within the packed bed. This model predicts the thermal performance of RTES during both charging and discharging. An expander is utilized as part of the power generation component, employing the Joule-Brayton cycle. This cycle comprises a closed Joule cycle for charging, or storing electricity as thermal energy, and an open-loop Brayton cycle for electricity generation. The study investigates the transient behavior of the integrated components, aiming to develop control strategies for optimizing system performance. Through detailed examination, this provides valuable insights into dynamic interplays and potential enhancements to improve the overall effectiveness and reliability of integrated RTES systems and power generation component.