in Virginia, geothermal heat flow reaching the surface (measured in milliwatts/square meter) is highest near Bath County
Source: Department of Energy, Geothermal Heat Flow and Existing Plants
in Virginia, geothermal heat flow reaching the surface (measured in milliwatts/square meter) is highest near Bath County
Source: Department of Energy, Geothermal Heat Flow and Existing Plants
Virginia has 20 thermal springs, ranging in temperature from 60-106°F. The water in Virginia's thermal springs is rainwater which is heated by the geothermal gradient as it travels underground before resurfacing.1
The state's greatest geothermal asset is the stable-temperature bedrock, which averages around 55°F near the surface. In the winter, that temperature is warm. In the summer, 55°F is cool.
Virginia lacks the geothermal potential for generating electricity as California does at The Geysers, but there is great potential for heating/cooling buildings. Geothermal energy is a renewable resource that could reduce the use of fossil fuels that produce greenhouse gas emissions. Ground source heat exchangers can use standard heat pump technology, but rely upon fluid moving through pipes in the ground rather than exchange heat with the air. In contrast to air-based heat exchangers, the fluid is always 55°F.2
geysers such as Old Faithful in Yellowstone National Park are generated by water heated at depth, reaching the boiling point, and then surging to the surface
The geothermal gradient temperature is an increase of 1.3-2.2°F per 100 feet in depth. For wintertime heating, geothermal wells could be drilled deeper in order to access warmer rocks below the surface.
temperature at depth, 200m below ground surface
Source: Virginia Department of Energy, Geothermal Resources for the Eastern United States (2013)
heat flow, the ability of bedrock to conduct heat, is greatest near Bath Countye
Source: Virginia Department of Energy, Geothermal Resources for the Eastern United States (2013)
Radioactive elements in granitic plutons generate heat more than other bedrock, and plutons buried deep below the Coastal Plain sediments may offer geothermal potential for deep wells. The US Department of Energy has provided over $7 million to West Virginia University, so it can drill 15,000 feet deep in 2023 to assess if deep wells in the eastern United States could provide a reliable supply of geothermal energy near Morgantown.3
geothermal energy potential in the United States
Source: US Energy Information Administration, Geothermal Explained: Where Geothermal Energy Is Found
The US Department of Energy launched the Enhanced Geothermal Shot in 2022, seeking to lower costs for enhanced geothermal systems by 90% by 2035.4
Traditionally, geothermal systems are designed with heat exchangers to transfer undrground heat (or coolness) to enclsed spacs in buildings on the surface. An additional possibility is to use fracking technology to pump water/fluids underground when solar/wind systems generate excess electricity, then extract the fluids when there demand for electricity increases at a different time of day.
If the undergound reservoir is pressurized by the pumping, then the fluid could be released as needed to create an artesian flow at the surface strong enough to power a generator producing electricity. Such a geothermal system could serve as a battery, as well as a source of heat. Virginia lacks especially hot temperaures underground, but may have geologic formations suitable for creating a geothermal battery system.5
a geothermal "battery" would store fluids in pressurized geologic formations, then extract the fluids to power a generator
Source: US Department of Energy, Geothermal Energy: A Glance Back and a Leap Forward
the US Department of Energy launched an earthshot in 2022 to cut the costs of geothermal energy
Source: US Department of Energy, Enhanced Geothermal Shot infographic