Objective

To increase awareness and implementation of the ESTCP-demonstrated underground thermal energy storage (UTES) technology, Andrews, Hammock & Powell, Inc. (AH&P), Consulting Engineers, developed an educational series of tools including seminars, webinars, websites, videos, guidelines, and software under this Technology Transfer Project. The topic-specific, on-demand webinars were hosted on the National Institute of Building Sciences’ (NIBS) Whole Building Design Guide website. Originally NIBS indicated they would host these webinars for at least two years, but the latest indications are that these webinars will remain active indefinitely. These webinars can be viewed at Continuing Education | WBDG - Whole Building Design Guide.

The Department of Defense has expressed interest in reducing its $4B energy utility bill, decreasing its water consumption, and increasing its inside-the-fence energy security/resiliency. All three of these objectives were achieved under the initial project EW-201135 using the rare (in the United States) state-of-the-art form of UTES energy storage.

Technology Description

There are two variations of UTES featured in this demonstration: Borehole Thermal Energy Storage System (BTES) and Aquifer Thermal Energy Storage System (ATES).

The BTES technology demonstrated in this project is a closed loop Groundloop Heat Exchanger system that utilized a bore field configured in a bullseye pattern, an adiabatic dry cooler, and reversing valves to redirect flow into the perimeter or the core of the bore field depending upon the season. The principle of operation for this technology was to utilize the adiabatic dry cooler in the dry mode during periods of cold outside air temperatures to efficiently dump heat from the building and bore field to the outside air and therefore “charge” the core of the bore field with “cold.” In the opposite season, the reversing valves changed position to use the stored energy from the core of the bore field to cool the building.

The ATES technology featured was similar to the BTES mentioned above but was an open loop system instead of a closed loop. With the ATES technology, energy was stored in the aquifer in either the cold well or the warm well. During the cooling season, cold water was pumped from the cold well and used to cool the building. The heat extracted from the building was then injected into the warm well. During the heating season, warm water was extracted from the warm well and used to heat the building.

Demonstration Results

The proposed Technology Transfer process to transfer UTES is believed to have been effective based on several factors listed below.

  • http://www.uteshub.com website increased the awareness of UTES to Engineers, Architects, Owners, Maintenance Personnel, and others that may be interested in alternative heating and cooling methods, at levels well beyond those anticipated in the Plan.
  • The quarterly newsletters and fact sheets assisted in informing procurement officials of the idea, and implementation of UTES.
  • AH&P’s proposed edits to the Whole Building Design Guide Unified Facility Guide Specifications, as it relates to UTES-specific technologies, are anticipated to be helpful and increase the adoption of this “new” (to the United States) technology.

Cost assessment is not applicable to a Technology Transfer Project. However, estimated costs for implementation of ATES and BTES systems are included in the final report from Energy and Water Project EW-201135, under which a Life Cycle Cost Analysis was completed. Costs of various critical components were either tracked or obtained from Contractors so the analysis could be applied to other military installations. Since each demonstration site involved construction funding from the military installation, all costs that could not be tracked directly were obtained from installing contractors. The critical components relevant to the geothermal heat pump-UTES technology tracked during the implementation of the demonstration project are listed in the final report.

Implementation Issues

Implementation issues related to the Technology Transfer were primarily limited to the impossibility of holding live seminars/workshops during the global pandemic. This turned out to be a blessing in disguise as the Live Webinars that were substituted allowed the project team to reach a larger audience and paved the way for the six On-Demand Webinars that are now hosted on the www.wbdg.org website in perpetuity.