A Little Elaboration and Clarification

By John McFerrin

            The March, 2022, issue of The Highlands Voice included a story about geothermal energy and its potential as a source of electricity in West Virginia.  Since then, I have heard from readers pointing out ways in which it was inaccurate or incomplete.  While not fake news, there were things in the story which could use some clarification.

There are hot springs in West Virginia

The story said that West Virginia does not have hot springs.  Untrue.  Of course we have several hot springs, including the ones at Berkeley Springs State Park where George Washington used to come for a soak.

While we do have hot springs where George Washington and countless others found relief, they are not hot enough to serve as markers for places where electricity generation from geothermal energy would be possible.   

At the hot springs in West Virginia water typically comes out of the ground at about 75 degrees.  Hot springs in Alaska typically produce water at about 165 degrees.  At our most famous hot springs—the ones at Yellowstone—the water emerges at about its boiling point.  When water emerges at these temperatures, it usually indicates that there is water not too far below the surface that would be hot enough to be used to generate electricity.  Water coming out of the ground at 75 degrees does not, at least not with current technology, indicate that there is nearby accessible water that is hot enough to generate electricity.

Geothermal energy is a viable source for home heating in West Virginia

            It is true, as the story said, that there is no known place in West Virginia where super hot water is found not far below the surface.  Because of this, there is no place in West Virginia where we could use geothermal energy to make electricity.  The exploration that is now occurring might discover super hot water close to the surface.  Technology might develop that allows much deeper drilling to reach such hot water.  With current knowledge and technology, however, there is no potential in West Virginia for making electricity from geothermal energy.

            This does not mean that geothermal energy is not a viable energy source for home heating.

            Most, and probably all, of the home geothermal heating systems in West Virginia work on the same principles as the heat pumps that most people are familiar with.  From about ten feet below the surface to about one thousand feet below the surface, the earth is a uniform temperature of about 54 degrees.  Home heating and cooling systems work by pumping water into these subsurface areas.  When the water returns to the surface, heat pumps can extract heat from the water in heating season and move heat from the air into the water in cooling season.  They are doing the same thing that conventional heat pumps do to the air only doing it more efficiently.

            It would also be possible, in West Virginia, to use geothermal energy to heat buildings or whole complexes.  Water hot enough to make electricity may not be available in West Virginia.  While we have springs that are hot enough to keep George Washington toasty, we may not have the blazing hot water near the surface that current technology requires to make electricity.

Most of the geothermal energy comes from the earth’s core.  Enough heat to generate electricity would be available anywhere if we drilled deeply enough.  While the answer to the question of how deep we would have to drill in West Virginia is still uncertain, it may well be that the technology does not exist to drill as deeply as we would have to go to reach water that is hot enough to generate electricity.

            The same technology that is used to heat individual houses—circulating water and heat pumps—could be used to heat larger buildings or even a whole city.  

Another approach to heating a city would be to drill deeper until the one finds water hot enough to heat buildings.  Water at that temperature (warm enough to heat buildings—but not make electricity) is very common and could be reached with existing technology.  The up front cost of such a system make it appropriate only for institutions such as colleges, the Capital complex, or whole cities.  Such systems are currently in use in such places as New Jersey, Minnesota, and Indiana which have no more geothermal resources than West Virginia does.