Enhanced Geothermal Systems Recommended for United States.

The Geothermal Energy Association and the US Department of Energy have made a decision to focus research and development in the area of Enhanced Geothermal Systems (EGS).  EGS is seen as a profitable route for geothermal energy production in the United States, as well as other nations such as Australia and Japan.  To date, the largest EGS project undertaken is in Australia.

EGS is a step further than conventional geothermal power, which relies upon both heat and water accessible below ground.  EGS, also known as “Hot-Dry Rock Geothermal” only needs a subsurface source of heat with favorable tectonic conditions.  Two wells are drilled; one is used to inject water below the surface, while the second well serves as a production well for harnessing the steam and hot water produced. (pictured below)

In today’s panel at the WIREC conference, Steve Chalk, the DOE Deputy Assistant Secretary for Renewable Energy, was advocating EGS technology for the future of America’s geothermal prospects.  He stressed that DOE is focused on the research and development aspect in order to make this source of renewable energy a reality in the near future.  Chalk commented that the FY 2008 budget has $20 million dollars allocated for geothermal research and the FY 2009 budget has been increased to $30 million  for this project.  His goal is to increase the FY 2010 budget to $50 million earmarked for geothermal energy development. Chalk ended by saying that "the best thing Congress could do to support geothermal would be to enact a durable, predictable policy to attract investors - a policy that lasts longer than the project cycle."

Several of the private sector representatives on the panel expressed their concern in accessing capital for the early development stage of geothermal, with exploration being the most expensive phase.  The risk is in private industry spending resources that result in dry wells.  Implementation of EGS technology would mitigate much of this risk by making dry-hot wells productive sources of geothermal energy.

Several of the members of the “Building Effective Government-Industry Collaboration” panel referenced a 2006 MIT study on EGS.  DOE relies heavily on the MIT study and the USGS is currently undergoing a new geothermal study to more accurately determine the potential of EGS in light of the MIT study.  The MIT study reports that EGS is viable in almost any region of the United States, giving it much more potential than conventional geothermal which is currently restricted to the Western states.

The MIT study states that geothermal energy has largely been ignored in the US as “a result of the widespread perception that the total geothermal resource is often associated with identified high-grade, hydrothermal systems that are too few and too limited in their distribution in the US to make a longer term, major impact at a national level.  This perception has led to undervaluing the long-term potential of geothermal energy missing an opportunity to develop technologies for sustainable heat mining from large volumes of accessible hot rock anywhere in the US.”

The DOE and private sector partners are largely focused on the potential of EGS for the future of geothermal in the US.  The MIT study is conclusive in reporting, “Geothermal energy from EGS represents a large indigenous resource that can provide base-load electric power and heat at a level that can have a major impact on the United States, while incurring minimal environmental impacts.  With a reasonable investment in R&D, EGS could provide 100 gigawatts or more of cost-competitive generating capacity in the next 50 years.  Further, EGS provides a secure source of power for the long term that would help protect America against economic instabilities resulting from fuel price fluctuations or supply distributions.”

These findings and their implications were the overall picture that the DOE and its partners presented at WIREC.  They are promoting research and development in order to bring EGS online as quickly as possible, seeking government matching funds and private sector investment concurrently.  

Read the entire MIT Study here:  www1.eere.energy.gov/geothermal/pdfs/future_geo_energy.pdf