january, 2018

25jan9:30 amISGS Seminar: Mr. Chuck Hammock, "Advanced Geothermal Heat Pump (GHP) Architectures Including Underground Thermal Energy Storage (UTES)"

Event Details


The Advanced GHP Architectures Including UTES seminar will explore the recently (2017) concluded DoD project that demonstrated the United States’ first Borehole Thermal Energy Storage (BTES) system and one of the country’s few Aquifer Thermal Energy Storage (ATES) systems at the Marine Corps Logistic Base Albany, GA (MCLB) and Ft. Benning, GA respectively. The fundamentals of a UTES system will be covered and compared against conventional GHP designs as well as the metered savings and paybacks associated with the BTES and ATES systems. Both technologies combined make up most of the UTES systems in the world, though other architectures like Cavern Thermal Energy Storage (CTES) are possible.

UTES designs move beyond the exploitation of the geology as a superior heat sink/source and configure the system to optimize it capacity to store heat and/or “cold”. In the so-called “closed loop” configuration, BTES systems feature concentric thermal zones, circuited in series and reversing valves to enhance storage capacity, efficiency and allow for a charging and discharging mode of operation.  In the open loop configuration of ATES, every groundwater well features a pump and injection valve so that each can serve as both a supply well and a storage well, thereby allowing for the capture of both the building’s waste heat and “waste cool”. Other unique technologies, that complement and enhance the UTES system, will be covered including:

  • A permanent, 2.6km long underground Fiber Optic based Distributed Temperature Sensing (DTS) system that monitors 1300 underground temperatures throughout the BTES.
  • A DTS based in-situ Distributed Thermal Response Test (DTRT) or Layered Thermal Conductivity Test (LTCT) that determined the layer-by-layer thermal conductivity (k) values of the geology and the Borehole Thermal Resistance (BTR) of the test bore.
  • Adiabatic Dry-Coolers utilized for Diurnal & Seasonal “Cold Capture” (heat rejection)
  • Heat Recovery Chiller-Heater, Water-to-Water Geothermal Heat Pumps that generate “free” space heating hot water and reconnect to the buildings existing chilled and hot water systems.

Beyond the DoD UTES project, the seminar will also cover other related topics like domestic water heating via GHPs and UTES for Combined Heat & Power (CHP) systems. A Q&A session will be held at the end of the 45-minute presentation.

About the speaker

Mr. Hammock during the past 35 years has been exclusively involved in the engineering of Heating, Ventilating and Air Conditioning (HVAC) systems for governmental, industrial, commercial and institutional clients at facilities throughout the United States and Internationally. His specialty and passion in this arena is centered on innovative deployments of Geothermal Heat Pumps (GHPs) systems for governmental, institutional, and commercial clients. He served as the Principal Investigator (PI) for the Department of Defense’s ESTCP project #EW-201135 where the integration of Underground Thermal Energy Storage (UTES) with GHP’s was demonstrated at Fort Benning and MCLB Albany, GA. He is a licensed Professional Engineer (PE) in multiple states and is one of the three founders of Andrews, Hammock and Powell, Inc., a US-based Consulting Engineering firm established in 1988 and located in Macon, Georgia.


(Thursday) 9:30 am


Leighton Conference Room (Room 101)


Illinois State Geological Survey