PRELIMINARY ASSESSMENT OF THE POTENTIAL GEOTHERMAL ENERGY RESOURCES OF FLOODED ABANDONED UNDERGOUND MINES IN OHIO

There are more than 7,000 known abandoned underground mines in Ohio, with a high percentage of these partially or completely filled with water. These abandoned mines are currently considered a geohazard due to the potential for mine subsidence or the deleterious effects of acid mine drainage.. An evaluation of the potential to recover geothermal energy resources from abandoned underground mines in Ohio for heating and cooling could lead to the beneficial reuse of these mines with an associated economic benefit to surrounding communities. To that end, the Ohio Department of Natural Resources, Division of Geological Survey began researching the state’s geothermal resources in July 2010 as part of a 40-state coalition to develop a new National Geothermal Data System—the key component of a coordinated effort to facilitate future development of renewable geothermal energy in the United States. Ohio is a national leader in the installation of geothermal heat pumps with approximately 10,000 installed during 2009. Approximately 250,000 acres of eastern Ohio contain flooded abandoned underground mines, storing an estimated 54 billion cubic feet of water; thus the potential for geothermal heating and cooling is enormous. A review of case studies worldwide where mine water has been successfully utilized for heating and cooling was completed; data mining of existing information on Ohio mine water quality, quantity, and temperature is underway; and a study protocol to evaluate individual mines is being developed. Hopefully this preliminary assessment will lead to a pilot project in Ohio using abandoned underground mines for geothermal heating and cooling.