Thermal Storage
Direct-use applications make efficient, real-time use of geothermal heat; however, the ground's ability to store and retain heat has opened new opportunities for innovative, large-scale heating and cooling for campuses, large facilities, and district energy systems.
RESPEC engineers are leading the way in developing in-ground thermal energy storage solutions, including GABESS, the Grid Amplified Building Energy Seasonal Storage system. GABESS uses proven, existing technology that can be installed and serviced by licensed contractors to heat and cool buildings.
PROJECT SPOTLIGHT
Thermal Storage at Joint Base Andrews
Environmental Security Technology Certification Program // Washington, DC, USA // 2023 - Present
Led by the Navy Geothermal Program Office, RESPEC has teamed with Lawrence Berkley National Laboratory to respond to Environmental Security Technology Certification Program Topic Area D8 – Thermal Microgrids for Efficiency and Lower Green House Gas Emissions.
The study is titled “Cost-Effective Thermal Micro-Grids Using GABESS for High Efficiency, Low GHGs, Resiliency, and ESCO Financeability.” Grid-Amplified Building Energy Seasonal Storage (GABESS, pronounced “gabes”) technology combines Air Source Heat Pumps (ASHPs), Water Source Heat Pumps (WSHPs), and Borehole Thermal Energy Storage (BTES). An ASHP delivers a greater quantity of cold or heat energy to the BTES than the electric power used by the ASHP, so stored energy in the BTES has been grid amplified. The heat or cold stored in the BTES will be recovered for building energy heating or cooling (not electricity). Because the BTES can retain heat or cold for months, it provides seasonal storage. GABESS can be applied to any size building, but works best when the BTES is large, so a multi-building district heating and cooling thermal microgrid (DHCM) is ideal.
The project is a prefeasibility study to develop cost-effective resiliency, efficiency, and carbon dioxide reduction by use of geothermal borehole seasonal and diurnal storage for building heating and cooling energy via hybrid geothermal and air-source chillers/heat pumps.
PROJECT SPOTLIGHT
District Heating and Cooling Thermal Microgrid Study
Rocky Mountain Power // Vernal, UT, USA // 2023 - Present
A project has been conceived to implement Grid Amplified Building Energy Seasonal Storage (GABESS) in a district heating and cooling thermal microgrid (DHCM) in Vernal City, Utah. GABESS is an integrated system of geothermal heat pumps, air source heat pumps, and borehole thermal energy storage (BTES). The DHCM will be a closed-loop pipe network that circulates water to each building. At each building, a water source heat pump will be used to provide heating and cooling, depending on each building’s particular needs at each moment in time. Building occupants will never know that the system has changed.
The feasibility study will evaluate whether a GABESS system installed in Vernal would provide economic benefits to the building owners who chose to connect and long-term financial sustainability for the City as Owner/Operator. A successful study will enable a follow-up front-end engineering design study and the beginning of infrastructure investment when opportunities arise (such as putting DHCM pipe in open trenches in the street for future use).
The technical factors to be examined include building HVAC energy performance, capital cost, and carbon dioxide reductions by conversion to the DHCM, the piping network configuration that links all the buildings, and the BTES configuration and modes of operation. Economic analyses will be performed, and overall system energy and emissions profiles and resilience will be summarized. The benefits that GABESS provides to the ratepayers of Rocky Mountain Power will be calculated to garner Rocky Mountain Power’s financial participation.
