Wylie Rosenthal

References Augustine, Chad R. "Hydrothermal Spallation drilling and advanced energy conservation technology for engineering geothermal systems" MIT 2009

Koskinen, Perttu E.P., Steiner R. Beck, and Jaakko A. Puhakka. "Ethanol and Hydrogen Production by Two Thermophilic, Anaerobic Bacteria Isolated from Icelandic Geothermal Areas."

Biotechnology and Bioengineering 101.4 (2008): 679-90. Wiley Periodicals. Web. 29 Mar. 2010. Thorsteinsson, Hildigunnur H., Jefferson W. Tester. “Barriers and enablers to geothermal district heating system development in the United States.” Energy Policy. 38.2(2010) 808-813. science direct. Web. 29 Mar. 2010.

Geothermal FAQs. US department of Energy

Kagel, Alyssa. The State of Geothermal Technology: Part II: Surface Technology. Washington, D.C. Geothermal Energy Association, 2008

Second Presentation

Questions for the second presentation

  1. One of the most persistent of problems with other renewable energy sources is that they tend not to provide power steadily and predictably. Is this true with geothermal? Are there fluctuations in underground heating that can make geothermal plants less efficient or maybe even damage them?

First Presentation

Questions from the first presentation

  1. Is corrosion of the pipes carrying the hot water from the Earth In binary-cycle plants a problem?
  2. What are the economics of widespread use of geothermal heat pumps for localized use?
  3. Geothermal plants are located near earthquake faults and volcanoes. Are they reliable?
  4. Do geothermal reservoirs "run out"? If so, how long do they last?
  5. Why are there so few geothermal power plants in South America? In the USA?
  6. How much geothermal potential is there in the United States? What fraction of our energy needs could we satisfy with geothermal energy?
  7. What are current production costs for geothermal energy?
  8. Do geothermal plants cause environmental problems?
  9. It appears that northern California is a center of geothermal production. How much power do the California geothermal plants generate? Can they be expanded?
  10. How large are geothermal power plants?
  11. How much of its energy does Iceland obtain from geothermal sources?
  12. What is the efficiency of a typical geothermal power plant?

Some further questions

  1. The geothermal plant at The Geysers in northern California has been linked by some to excess seismic activity. Is the connection real or imagined?
  2. What fraction of Iceland's electric power and heating comes from geothermal sources? How far along the path to a hydrogen economy are they?
  3. Is hydrolysis more efficient with hot water? Is this approach being used in Iceland?
  4. Should new homes be built with geothermal heat pumps? Would it be more cost-effective to use heat pumps or to insulate buildings really well?
  5. Are there subsidies in California for residential geothermal systems? elsewhere in the United States?
  6. Are geothermal installations used for base load electricity or peak load?
  7. What is the typical high temperature of the working flui

~Peter Saeta 2010 March 10 at 10:14 PM PST

Presentation 1

The performance of geothermal reservoirs Is determined by the reservoir type, reservoir are categorized by

  • fluid properties
  • rock properties
  • temperature
  • Geological structural
  • Stratigraphy.
1. Enclosed, static trap reservoirs, trapped by overlying rock formations with lower permeability.

similar to typical oil and gas reservoirs

2. Stratigraphic-bound reservoirs: reservoir between layers of sedimentary

rock Found in the Imperial Valley of southern California

3. Continuously-flowing fluid reservoirs. Ex. Rainwater sinks into the ground and slowly moves through faults and fractures in the earths crust

Means of generating Power

  1. Binary Cycle Power Plant
Uses lower-temperatures (200° F – 300° F)
->Hot water is passed through a heat exchanger
->Secondary fluid vaporizes turning the turbines,
->secondary fluid is recycled
->Geothermal fluid is condensed and returned to the reservoir
5 to 8 cents per kWh.
Lower-temperature reservoirs are more common
  1. Dry Steam
1050°F - 1220° F Steam extracted
Steam sent directly through turbine
Most commercially attractive
Dry steam or vapor reservoirs are rare
  1. Flash Steam Plants
Steam with T>300° F
High-pressure water is depressurized ("flashed") to produce steam.
Steam then turns turbines, which drive generators that generate electricity.
Energy produced this way currently costs about 4-6 cents per kWh.


  • How efficient can the process be?
  • What are the limitations? -what places can you use this? if fully used how much will it help?
  • How much does geothermal energy cost?
  • Are there negative environmental impacts?
  • The mechanics of getting power
  • How reliable is geothermal, is it anymore susceptible to seismic activity?

Urban Planning

  • How much of an effect does public transportation have on emissions?
  • Are apartment buildings more environmentally sound?
  • Disposal of trash
  • What effect will increased gas prices have on cites like LA?