Geothermal power

Presently, designs for radial inflow turboexpanders in sizes up to 70 MW are available for use in geothermal power plants. Following are some of the most important features that make turboexpanders ideal for the reeovery of power from the vast available resourees of pressurized gas streams. 

Diagram from paper by The Ben Holt Co. Advaneed Binary Cyeles for Geothermal Power Generation. ... 

Application performance data for Mammoth Lakes, CA geothermal power generating plants... 

Geothermal power plant located in a lava field in Blue Lagoon, Iceland. (Corbis-Bettmann)... 

Some geothermal power plants use a combination of flash and binai y cycles to increase the efficiency of electricity production. An initial flash creates steam that drives a turbine then the binai y cycle is run, using either the hot water remaining after the initial flash or the hot exliaust from the turbine. 

The world s first geothermal power station begins operation in Italy. 

Iceland, an island nation with abundant hydroelectric and geothermal power sources close to where people live, is using natural power sources to convert water into hydrogen and oxygen. In April 2003, Iceland opened its first hydrogen filling station for fuel-cell vehicles. If this initiative proves successful, perhaps the rest of the industrialized world will eventually convert to a hydrogen-fueled economy. 

Sato, K. (1988) Mori geothermal power plant. In Geothermal Fields and Geothermal Power Plants in Japan. Int. Syrap. Geothermal Energy, Kumamoto and Beppu, Japan, November 10-14 pp. 21-25. 

Location Mud holes geothermal power plants deep terrestrial oil fields Submarine hot springs vents or black smokers deep submarine oil fields... 

The wind site areas at Tehachapi Pass and San Gorgonio are believed to have a similar potential. Geothermal power would be another renewable source. A problem in generating hydrogen this way is the long-distance pipelines required since the gas is leaky compared to other products. 

Figure 17.1. Elements of a hydrogen corridor between Iceland and the EU, based on hydro- or geothermal power.

The cheapest hydrogen-corridor options are hydrogen based on hydropower from Romania, the Ukraine and Bulgaria, followed by hydrogen from hydropower and geothermal power in... 

Total geothermal power potential Total hydropower potential... 

Hydrogen from hydro or geothermal power from Iceland offers the lowest barriers with respect to competing utilisation possibilities electricity export via electricity grid is less attractive, owing to Iceland s isolated position. 

At a geothermal energy source, dry steam at 700 kPa and 170°C is available at a mass flow rate of lOOkg/sec. A barometric condenser at lOkPa is used to decrease the turbine exhaust temperature. Find (a) the power produced by the geothermal power plant as shown in Fig. 2.22a. (b) What is the power produced without the barometric condenser ... 

Figure 2.22b Dry-steam geothermal power plant without condenser.

More commonly than it puts out dry steam, a geothermal well puts out a mixture of steam and water above 130°C, or just hot water. A separator is needed in a hot water steam mixture geothermal power plant to separate the flashing steam from the hot water, as shown in Figure 2.23. An additional throttling valve is required to generate saturated steam in a hot-water geothermal power plant. 

Figure 2.23 Hot water-steam mixture geothermal power plant.

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