Techno-Economic Analysis of Hybrid Geothermal Heat Pump System with Solar Thermal Driveway Collector and Seasonal Underground Thermal Energy Storage
Researcher: Samuel Chan
Principal Investigator: Professor Jefferson Tester
Rather than installing rooftop solar thermal panels, our group is investigating the feasibility of putting self-customized "solar thermal collectors" underneath the driveway to extract heat for residential space heating. Due to mismatch supply and demand of thermal heat, seasonal underground thermal energy storage is implemented. Stored heat can be extracted by geothermal heat pump. This idea came from commercial heated driveway system to melt snow and ice in winters. Our design is reversing the mechanism of such system. Sun light hits the ground, and energy is transferred to water running through the tubes underneath the driveway primarily by conduction. A much larger available driveway area is used to compensate lower efficiency of the solar thermal collectors due to asphalt cover. Economic and environmental benefits are also taken into account when techno-economic analysis is performed. Simulations are run using COMSOL. Steady state simulations are done to find the best configurations of water flow rate, tube spacing, thickness of asphalt, as well as other parameters. Second, transient simulations are to simulate system performance and calculate amount of energy extracted throughout operating period (roughly from May to September). Currently, more detailed works are being done to prepare to publish our findings.