Geothermal Technologies Explained For the Rest of Us

Geothermal Technologies Explained For the Rest of Us

The wind, sun and tides are all great sources of clean and renewable energy, but you have to take what you can get when the sun is shining, the wind is blowing and the waves are rolling.
tweet me:
#Geothermal #Technology Explained For the Rest of Us via @GeoJayegg

Multimedia from this Release


Green Builder Media

Friday, May 29, 2015 - 9:00am

CAMPAIGN: Ethical and Sustainable Living


THE US DEPARTMENT OF ENERGY (DOE) says that geothermal energy, a virtually untapped energy resource derived from the earth's heat, is more vital today than ever—it supplies clean, renewable power around the clock, emits little or no greenhouse gases, and takes a very small environmental footprint to develop. By developing, demonstrating, and deploying innovative technologies, GTO's efforts are helping stimulate the growth of the geothermal industry within the renewable energy sector and encouraging quick adoption of technologies by the public and private sectors.

Jeffery Tester of Cornell University in NY says that the total amount of [energy] at accessible depths has been estimated to be on the order of 10 billion quads (a quad is the energy equivalent of about 180 million barrels of oil and 90 quads represents the total US energy consumption in 2001). This is about 300 times greater than the fossil fuel resource base that includes all petroleum, natural gas, and coal. (Tester, et al. 1989).

So, what are we waiting for? This might require a short primer; please read on:

There are 4 main types of geothermal technologies:

  1. Hydrothermal
  2. Enhanced Geothermal Systems
  3. Geothermal, Direct Use
  4. Geothermal, Low Temperature

Hydro-thermal. Like the familiar “Old Faithful” geyser in Yellowstone National Park, hydrothermal power provides super-heated water to drive electrical generation turbines.

Enhanced Geothermal Systems. This is “hot, dry rocks”, and usually quite deep that require water to be pumped down to the source where it is turned into steam to drive electrical generation turbines.

Geothermal,  Deep Direct Use (Hot Water). This is water that is hot enough straight out of the earth to provide building heat, domestic hot water, and anything else below about 200F.

Geothermal, Low Temperature (Neutral or Shallow Earth Temperature). This is the least understood and yet the most useful technology. This technology requires a type of Heat-Pump designed to take the energy available just below the surface, and pump it up to a usable temperature for heating (and cooling).  This is super-efficient considering the heat pumps use only about 1 unit of electricity to pump 4 units of heat.