Executive Summary : | Buildings consume 20% of the economy's total energy and contribute to 40%-50% of thermal end-uses, primarily driven by cooling and heating. Energy storage is crucial due to the rapid deployment of renewable power and its intermittent nature. Thermal energy storage (TES) systems have a close relationship between energy and power densities, with the heat transfer rate (power) mainly dependent on the module's design and material properties. The usable stored energy in a TES module varies for a specified threshold value of temperature. Research has focused on increasing the heat transfer rate from TES devices, but there is potential to optimize the design of TES modules for specific applications and provide interactivity with the grid like electrochemical batteries. This project proposes developing optimized TES modules to improve integration with building energy systems, particularly heating, ventilating, and air-conditioning (HVAC) systems. The project will focus on commercial building HVAC systems, which can be extended to residential HVAC systems in the future. Detailed analyses of commercial building HVAC systems will be conducted to analyze peak demand and calculate optimal duration and storage capacity using a thermodynamic model integrated with TES. The Ragone framework will be used to evaluate the designs of TES modules, focusing on features such as heat exchanger geometry, TES material thickness, and material properties. Lab-scale experiments will be conducted to generate Ragone plots similar to simulations and validate models. The final design will be suitable for easy integration with existing and new HVAC systems, improving the fundamental understanding of TES design optimization based on energy and power densities. |