Enhanced Geothermal Systems (EGS)

From Open Energy Information

Geothermal Technologies

There are many types of Geothermal Technologies that take advantage of the earth's heat:

EGS Schematic.jpg
Enhanced Geothermal Systems:
Enhanced Geothermal Systems (EGS) are human engineered hydrothermal reservoirs developed for commercial use as an alternative to naturally occurring hydrothermal reservoirs, which are not known to be abundant.
Other definitions:Wikipedia Reegle

In 2009, the installed capacity of geothermal power plants in the United States was just over 3,000 MW.[1] A study conducted by the Massachusetts Institute of Technology (MIT)estimated that there is 100 GW (over 33 times the 2009 capacity)of electricity that could be produced in the United States with the addition of EGS systems. [2]

What is EGS?

EGS reservoirs are made by drilling wells into hot rock and fracturing the rock sufficiently to enable water to flow between the wells. The very hot water exits the reservoir via production wells. When the water reaches the surface, it passes through a power plant where electricity is generated. Water is returned to the reservoir through injection wells when it leaves the plant, thus completing a loop. Plants using a closed-loop system to generate electricity do not release any fluids to the atmosphere and will not have any greenhouse gas emissions.[3]

Creating an Enhanced Geothermal Reservoir

The Department of Energy and its Geothermal Technology Program have proposed a 5-step process for the development of an EGS reservoir and electricity generation plant[3]. The steps are

  1. Find a site
  2. Create the reservoir
  3. Complete a wellfield
  4. Operate the reservoir
  5. Operate the facility

Each step requires implementation of technologies specialized for the uniquely challenging geothermal environment[3].


<references> [3] [1] [2]

  1. 1.0 1.1 (Published: July 2009) "US DOE 2008 Renewable Energy Data Book"
  2. 2.0 2.1  "The Future of Geothermal Energy"
  3. 3.0 3.1 3.2 3.3  "US DOE EERE Geothermal Technologies Program, Enhanced Geothermal Systems Technologies"