Background
Flash Steam Geothermal Power Plants are the most common type of Geothermal Power plant in the United States. The United States is the leader in Geothermal Power with capacity of 2,200 MW. The largest Flash Steam Power Plant is the Coso Geothermal Power Plant in California (See figure 1).
Figure 1: The CalEnergy Navy I flash geothermal power plant at the Coso geothermal field.
Geothermal technology relies on extracting heated water from below the surface of the earth. Flash Steam power plants are classified by core water temperatures of at least 175C. Geothermal Power is a clean, reliable, and sustainable alternative power source. Below you will find an informative video about the technology of a typical Geothermal Power Plant.
Methodology
At high pressure below earth's surface the water exists as compressed liquid. Pipeline is installed to tap into the resource. When the liquid water reaches atmospheric at the surface a portion of it immediately flashes to steam. The steam portion is redirected into a steam turbine where power is produced. The exhaust is then piped to a condenser where it is returned to liquid. This hot liquid water can then be used for further heating applications prior to reinjection back into the rock.
Advantages
- Very low emissions
- Safe and Reliable
- Immune to varying weather conditions
- Cost effective over life of plant
- Sustainable
- Small footprint
- No fuel cost
Disadvantages
- High initial cost
- Increased risk of seismic activity
- Location sensitive
- Risk of overexploiting resources
Comments
Geothermal power is of particular significance in today's economy. With rising fuel costs and environmental concerns, Geothermal Power is becoming a more attractive alternative to traditional fossil fuel based plants. Drilling was once a major obstacle for choosing Geothermal Power. However, with recent developments in drilling technology drilling is becoming less of a financial burden.
Recent Developments in Geothermal Drilling
As oil costs continue to rise we foresee geothermal plants sprouting up in more states. Figure 2 shows the regions of the United States where Geothermal activity is highest.
Figure 2: Geothermal "Hot Spots" in the United States
Conclusions
In certain regions, Geothermal plants have potential to become significant sources of power. The technology is already proven and will only improve with further refinement.
Group Members:
Aaron Fisher
Chris McKinney
