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<br /> <br />12 <br />The primary focus is on electrifying building heating and cooling demands through the use of water source <br />heat pumps in the buildings. Water source heat pumps offer a sustainable, reliable, and often cost-effective <br />energy solution for communities, reducing reliance on fossil fuels and mitigating GHG emissions. The <br />estimated cost for the in-building heat pump equipment is $113.5 million. <br />4.2 Thermal Energy Solutions <br />The district energy system allows for a combination of serval energy sources, and this analysis seeks to <br />determine the most cost-effective and energy efficient options to serve the Rice Creek Commons community. <br />Several energy sources were analyzed, including connection to the TCAAP groundwater remediation system <br />(TGRS), closed-loop geothermal wellfields, in-ground heat exchangers, and aquifer thermal energy storage <br />(ATES). All of these technologies could potentially interact with the groundwater on-site in various ways. <br />Despite restrictions on groundwater extraction due to contamination, the Amended Environmental Covenant <br />and Easement for the property specifically permits technologies that do not withdraw water, such as <br />geothermal heat exchangers. <br />4.2.1. GROUNDWATER REMEDIATION SYSTEM <br />The RCC development site houses the TCAAP Groundwater Remediation System (TGRS) that continuously <br />extracts 1,750 gallons per minute (GPM) of water for treatment (as of 2024). This water is treated before <br />being discharged into a nearby quarry, as shown in Figure 4. The system's consistent water flow makes it a <br />potential source to facilitate heat exchange for a tepid water loop. The treated water would not directly flow <br />within the tepid water loop, the loop itself would be a closed system containing only clean water from the <br />development’s water supply. At its current rate of extraction, the TGRS could potentially provide <br />approximately 9 MMBtu/hr or 730 tons of heating and cooling capacity. This represents 13% of the total site <br />cooling load and 30% of the site heating load on the district energy system. <br /> <br /> Figure 4. District energy connection to the ground water remediation system. <br />With much of the necessary infrastructure already in place, this presents a low-cost opportunity for energy <br />capture and extraction. The TGRS connection would require adding heat exchangers, pumps, and controls to <br />the treatment building. The estimated cost to connect to a district system is $1.75 million (projected 2027 <br />dollars), which equates to approximately $200,000 per MMBtu/hr or $2,400 per ton of cooling capacity. This <br />analysis did not cover the regulatory approvals necessary for use of the TGRS, which is owned by the US <br />Army.