NEWS - April 4, 2013 - AGWT Workshop: Geothermal Heating and Cooling Innovations, Tallahassee Florida

The American Ground Water Trust hosted the second geothermal workshop in its 2013 series, “Geothermal Heating and Cooling Innovations: Design, Financing and Regulation” in Tallahassee, Florida on April 4.  The audience hailed from a cross section of HVAC engineers, architects, geothermal installers, members of the Florida Departments of Health and Environmental Protection and the U.S Air Force. 

Chuck Hammock (left) is a Principal Engineer at Andrews, Hammock & Powell, Inc. (Macon, GA) and heads its geothermal projects division.  Mr. Hammock also serves on the Board of Directors of the American Ground Water Trust.  Chuck presented a session on Aquifer Thermal Energy Storage (ATES) and Borehole Thermal Energy Storage (BTES).  These specialized geothermal loop methods are common in Europe, but are essentially non-existent in the United States.  Both technologies reverse the flow direction within the geothermal loop on a seasonal basis.  This positively enhances the natural subsurface energy conditions and creates opportunity for increased GHP performance.  The BTES method uses a modified closed loop while the ATES system is based on large open loop borehole fields that directly access groundwater.  Both BTES and ATES methods require well defined knowledge of local groundwater quality, quantity and flow conditions to optimize energy exchange and system response.  AH&P is currently completing demonstration projects for these geoexchange methods at Department of Defense sites in Georgia.   

Formation thermal conductivity is a fundamental variable in the geothermal closed loop design process.  David Henrich (right), Vice President in charge of production of thermal conductivity test equipment at Precision Geothermal LLC (Maple Plain, MN) explained the methodology of FTC testing and how the test borehole can be incorporated into the final loop field.  He emphasized the need for using appropriate equipment in order to collect valid data and when the test can be most valuable to a geothermal designer.  The test should be considered for moderate to large commercial projects.  A FTC test usually is not appropriate for open loop systems.


Keith Swilley (left), Marketing Manager, Gulf Power Company (Pensacola, FL) and Board member of the Geothermal Exchange Organization (GEO) demonstrated the environmental benefits and significant reduction in operating costs GHP space conditioning systems create in comparison to conventional air-conditioning and heating systems.  The 30 percent Federal tax credit for residential properties, and the 10 percent tax credit and accelerated depreciation for commercial properties, remain in effect for GHP conditioning systems put into operation through new construction or renovation before December 31, 2016.  Gulf Power and other Florida electric utilities offer additional incentives that are outlined at