Geothermal Energy

GEOTHERMAL ENERGY

NOZAR POURSHEIKHIAN – [email protected]

TEACHER: MR. MOHAMMAD POUR

QUCHAN UNIVERSITY OF NEW TECHNOLOGIES ENGINEERING

1Quchan University of Advanced Technologies Engineering 2013

CONTENTS1. Introduction to Geothermal Energy

2. History

3. Electricity

4. Types

1. Liquid-dominated plants2. Thermal energy3. Enhanced

5. Economics

6. Resources

7. Renewability and Sustainability

8. Environmental effects

9. References

2Quchan University of Advanced Technologies Engineering

INTRODUCTION TO GEOTHERMAL ENERGY


DRY STEAM SCHEMATIC


SINGLE FLASH STEAM SCHEMATIC


BINARY CYCLE SCHEMATIC


HISTORY• Hot springs have been used for bathing at least

since Paleolithic times.

• The world's oldest geothermal district heating system in Chaudes-Aigues, France, has been operating since the 14th century.

• In the 20th century, demand for electricity led to the consideration of geothermal power as a generating source in Iceland. It was the world's only industrial producer of geothermal electricity.

• In 1960, Pacific Gas and Electric began operation of the first successful geothermal electric power plant in the United States at The Geysers in California.


ELECTRICITY• The International Geothermal Association (IGA) has reported that

10,715 megawatts (MW) of geothermal power in 24 countries is online, which is expected to generate 67,246 GWh of electricity in 2010.

• In 2010, the United States led the world in geothermal electricity production with 3,086 MW of installed capacity from 77 power plants.

Installed geothermal electric capacity

Country Capacity(MW)2007

Capacity(MW)2010

Percentage of national electricity production

Percentage of global

production

U.S.A 2687.0 3086.0 0.3 29

Philippines 1969.7 1904.0 27.0 18

Indonesia 992.0 1197.0 3.7 11

I.R.Iran 250.0 250.0 <0.1 <5


•Geothermal electric plants were traditionally built exclusively on the edges of tectonic plates where high temperature geothermal resources are available near the surface.

•The thermal efficiency of geothermal electric plants is low, around 10–23%, because geothermal fluids do not reach the high temperatures of steam from boilers.

•Exhaust heat is wasted, unless it can be used directly and locally, for example in greenhouses, timber mills, and district heating.

•Because geothermal power does not rely on variable sources of energy, unlike, for example, wind or solar, its capacity factor can be quite large – up to 96% has been demonstrated.

•The global average was 73% in 2005.


TYPES

1. Liquid-dominated plants

•Liquid-dominated reservoirs (LDRs) are more common with temperatures greater than 200 °C (392 °F) and are found near young volcanoes surrounding the Pacific Ocean and in rift zones and hot spots.

•Pumps are generally not required, powered instead when the water turns to steam.


2. Thermal energy

•Lower temperature sources produce lower energy. Sources with temperatures from 30-150 C are used without conversion to electricity for as district heating, greenhouses, fisheries, mineral recovery, industrial process heating and bathing.

•Home heating is the fastest-growing means of exploiting geothermal energy, with global annual growth rate of 30% in 2005 and 20% in 2012.


• Iceland is the world leader in direct applications. Some 93% of its homes are heated with geothermal energy, saving Iceland over $100 million annually in avoided oil imports. Reykjavík, Iceland has the world's biggest district heating system. Once known as the most polluted city in the world, it is now one of the cleanest.


3. Enhanced•Enhanced geothermal systems actively inject water into wells to be heated and pumped back out.

•The water is injected under high pressure to expand existing rock fissures to enable the water to freely flow in and out.

•The technique was adapted from oil and gas extraction techniques.


ECONOMICS• For making economic projections, estimates of well drilling and

completion costs to depths of 10,000 m are needed for all resources.

• In recent years, there have been fewer than 100 geothermal wells drilled per year in the United States and very few of them are deeper than 2,800 m (9,000 ft.), which provides no direct measure of well costs.

Direct Capital Costs (US $/kW installed capacity)

Plant Size High Quality Resource Medium Quality Resource

Low Quality Resource

Small plants(<5 MW)

Exploration: US$400-800Steam field: US$100-200Power plants: US$1100-

1300Total: US$1600-2300

Exploration: US$400-1000 Steam field: US$300-600

Power Plant: US$1100-1400Total: US$1800-3000



Med Plants (5-30 MW)

Exploration: US$250-400 Steam field: US$200-

US$500Power Plant: US$850-1200

Total: US$1300-2100



Normally not suitable

Large Plants (>30 MW)





Normally not suitable


RESOURCES• Geothermal energy exists in high enthalpy (volcanoes, geysers) and low

enthalpy forms (heat stored in rocks in the Earth’s crust). Nearly all heating and cooling applications utilize low enthalpy heat, called ground source heat.


RENEWABILITY AND SUSTAINABILITY

•Geothermal power is considered to be renewable because any projected heat extraction is small compared to the Earth's heat content.

•Not steady-state

•Heat depleted as ground cools.

•With a capacity factor of 90-95%, geothermal electricity generation could offset coal, natural gas, or nuclear power as a base load supply in the electrical energy market.

•Many companies purchase renewable energy as part of their environmental programs. Intel, Kohl’s, Microsoft, Wal-Mart, Whole Foods, and Staples are among the top 10 users of renewable energy.


ENVIRONMENTAL EFFECTS• Extracting large amounts of water can cause land subsidence, and this

can lead to an increase in seismic activity.

• Release of steam and hot water can be noisy.

• Some geothermal facilities produce solid waste that must be disposed of in approved sites.

• A geothermal power plant emits 35 times less carbon dioxide (CO2) than the average U.S. coal power plant per kilowatt of electricity produced.

• Issues of noise, safety, visual impacts,

and land use associated with drilling

and production operations are also

important but fully manageable.

• Geothermal has minimal land and

freshwater requirements.


REFERENCESUniversity of Michigan

Center for Sustainable Systems

http://css.snre.umch.edu/

University of Colorado

Stephen Lawrence - Geothermal_Energy.ppt

Massachuset Institute of Technology

http://geothermal.inel.gov/

Calpine Corporation

http://calpine.com/

Wikipedia, the free encyclopedia

http://wikipedia.org/


Geothermal Energy

Education

Transcript of Geothermal Energy