Online Access to America's Geothermal Resources
Advances in technology are making it easier for consumers and businesses to better understand how they are using and saving energy. Geothermal energy is a renewable resource that is underutilized. Leveraging data and innovation are ways to promote a clean energy economy in America. The State Geothermal Data project, organized by the Association of American State Geologists with funding from the United States Department of Energy, is bringing data from all 50 states into the National Geothermal Data System, in order to identify and characterize geothermal energy resources across the nation.
On May 28, 2014, The National Geothermal Data System launched with 9 million data points from 50 states.
Geothermal Use in Missouri
Geothermal energy is generally thought of as reservoirs of hot water that exist at varying temperatures and depths below the Earth's surface. Deep wells can be drilled into underground reservoirs to tap steam and hot water that can be brought to the surface for use in a variety of applications, including electricity generation, direct use, and heating and cooling. In the United States, most geothermal reservoirs are located in the western states, however, people across the nation can take advantage of the relatively constant temperatures of the earth to heat and cool their homes with ground source heat pumps.
Though the state of Missouri does not have hot springs, fumeroles or any of the geothermal features found in some western states, Missourians use the moderating influence the earth to heat their homes in winter and cool them in summer. This is done through the use of ground source heat pumps. The Missouri Department of Natural Resources, Geological Survey Program regulates the construction of some types of heat pump systems and provides information online.
There are three basic types of ground source heat pump systems – closed loop vertical, closed loop horizontal and open loop. Geological considerations will play a role in determining what type of system is best. Other considerations, such as lot size, also play a role.
- Open loop systems use groundwater as the heat exchange fluid. The well is usually also used as a drinking water supply. Quality of groundwater for this type of system must be a consideration. The Missouri Department of Natural Resources, Water Resources Center provides information about groundwater provinces in Missouri.
- Closed loop horizontal systems require the installation of pipe filled with approved heat exchange fluid in trenches. Construction of trenches depends on type and thickness of unconsolidated earth material. The Geological Survey Program has applicable data in the form of surficial materials maps and thickness maps. The lithology log data set, part of the State Geothermal Data Project, will be available for download soon.
- Closed loop vertical systems require the installation of pipe filled with approved heat exchange fluid in a vertical borehole. In most cases this borehole will be drilled into bedrock.
Geothermal Investigations in Missouri
Understanding the earth beneath our feet is the first step in understanding the world around us. Geologic maps are the most fundamental source of geologic information for the earth sciences. Geology affects everything from ecology to highway construction. Bedrock maps contribute to our knowledge of the likelihood of damage from earthquakes, landslides or sinkhole collapse and they are used for exploration and development of mineral, fuel and groundwater resources.
Additional Data Presently Available
- Heat pump log data set (indicates the current distribution of heat pump systems in Missouri and provides lithologic information) Excel File – August 2011
- Bottom hole temperature (derived from oil and gas well logs, the information will be used to create an updated aquifer temperature map) Excel File – August 2011
- Geologic map
- Depth to bedrock map (provides information critical to heat pump installation)
- Whole rock chemistry data set (provides information for determining rock unit suitability for various construction and industrial purposes)
- Borehole lithology log data set (lithologic descriptions of well cutting from water, oil and mineral test wells located throughout the state)
- Aquifer temperature map (last updated in 1981, aquifer temperature map may be used to indicate new geothermal resources)
- Trace constituent chemistry data set (water quality reports from public water supply districts)