H. Soroush, E. Gentry, R. Wichuk
Teverra LLC,
United States
Keywords: cold reservoir thermal energy storage (RTES) subsurface energy storage geological uncertainty thermo-hydraulic simulation sedimentary reservoirs low-carbon cooling
Summary:
Reservoir Thermal Energy Storage (RTES) offers a compelling route to decarbonize large cooling loads in sectors such as data centres, industrial facilities and district energy networks. By storing cold (rather than heat) underground during off-peak periods and recovering it during peak demand, subsurface cold RTES systems can reduce electricity consumption, lower operational cost and cut greenhouse-gas emissions. This study explores the application of cold‐storage RTES in sedimentary reservoirs to address long-duration cooling needs. We present a 3-D numerical simulation framework that couples geologic modelling, petrophysical property assignment and thermo-hydraulic fluid‐flow simulation to evaluate cold RTES performance in a conceptual sandstone reservoir under uncertainty. The investigation focuses on how geologic heterogeneity, reservoir geometry and operational parameters (well layout, injection rate, storage duration) influence key performance metrics including cooling recovery efficiency, breakthrough timing and system stability. Results show that spatial variability in permeability, porosity and thermal conductivity critically affects cold‐storage performance: reservoir geometry and thermal property distribution govern thermal‐front propagation, flow path development and the timing of cold breakthrough. The simulation outcomes provide guidance on optimal well placement and injection strategies to maximise efficiency while balancing subsystem reliability and long-term sustainability. In conclusion, the study demonstrates the value of integrating geological realism with efficient numerical workflows for early-stage RTES site screening and design. Cold subsurface thermal energy storage emerges as a viable alternative to conventional mechanical cooling in suitable geological settings, offering a pathway to flexible, low-carbon cooling systems. Our findings contribute to the broader field of non-battery long-duration energy storage and provide a technical framework for optimizing cold RTES systems under subsurface uncertainty.