Geothermal energy power from the earth Geothermal energy

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Geothermal energy: power from the earth ØGeothermal energy is the energy produced by heat

Geothermal energy: power from the earth ØGeothermal energy is the energy produced by heat within the Earth. Øwater deposits in the Earth’s crust are heated by geothermal energy. ØThe United States is the world’s largest producer of geothermal energy.

Steam rises through a well, it drives turbines, which generate electricity. The leftover liquid,

Steam rises through a well, it drives turbines, which generate electricity. The leftover liquid, water, is returned to Earth’s crust because it can be reheated by geothermal energy and used again.

Geothermal energy technologies can be broken into four major categories: ØConventional hydrothermal, Ø low-temperature,

Geothermal energy technologies can be broken into four major categories: ØConventional hydrothermal, Ø low-temperature, ØEGS(Enhanced Geothermal Systems) and Ø direct use, including geothermal heat pumps (GHPs). v The first three categories generate electricity, while the fourth is used primarily for heating and cooling and hot water production.

EGS-A NEW TECHNOLOGY ØUntil recently, geothermal power systems have only exploited resources where naturally

EGS-A NEW TECHNOLOGY ØUntil recently, geothermal power systems have only exploited resources where naturally occurring water and rock porosity is sufficient to carry heat to the surface. Ø Enhanced Geothermal Systems (EGS) are a new type of geothermal power technologies that do not require natural convective hydrothermal resources. ØEGS technologies "enhance" and/or create geothermal resources in this hot dry rock (HDR) through hydraulic stimulation.

HOW EGS WORKS? ØThe permeability can be enhanced by pumping high pressure cold water

HOW EGS WORKS? ØThe permeability can be enhanced by pumping high pressure cold water down an injection well into the rock. ØWater travels through fractures in the rock, capturing the heat of the rock. ØHeat captured is converted into electricity using either a steam turbine or a binary power plant system.

Development of Geothermal Power: Project Cycle The primary stages of the geothermal development cycle

Development of Geothermal Power: Project Cycle The primary stages of the geothermal development cycle are : Øexploration, ØResource confirmation, Ødrilling and reservoir development, Ø plant construction and power production. v. Each of these steps carries with it different varieties and levels of risk.

Development Constraints: Øinclude factors such as the comparative low cost of petroleum and gas

Development Constraints: Øinclude factors such as the comparative low cost of petroleum and gas and environmental issues. ØEnergy source such as wind, solar and hydro are more popular and better established; these factors could make developers decided against geothermal. ØHarmful gases can escape from deep within the earth, through the holes drilled by the constructors. The plant must be able to contain any leaked gases.

GEOTHERMAL ENERGY IN INDIA ØIndia has reasonably good potential for geothermal; the potential geothermal

GEOTHERMAL ENERGY IN INDIA ØIndia has reasonably good potential for geothermal; the potential geothermal provinces can produce 10, 600 MW of power. ØBut yet geothermal power projects has not been exploited at all, owing to a variety of reasons, the chief being the availability of plentiful coal at cheap costs. ØIndia will need to start depending on clean and eco-friendly energy sources in future; one of which could be geothermal.

Common Technologies ØFlashed steam plant. ØDry steam plant. ØHybrid power plant.

Common Technologies ØFlashed steam plant. ØDry steam plant. ØHybrid power plant.

Flashed steam plant: ØThe extremely hot water from drill holes when released from the

Flashed steam plant: ØThe extremely hot water from drill holes when released from the deep reservoirs high pressure steam (termed as flashed steam) is released. ØThis force of steam is used to rotate turbines. The steam gets condensed and is converted into water again, which is returned to the reservoir. Flashed steam plants are widely distributed throughout the world.

Dry steam plant: ØUsually geysers are the main source of dry steam. Those geothermal

Dry steam plant: ØUsually geysers are the main source of dry steam. Those geothermal reservoirs which mostly produce steam and little water are used in electricity production systems. ØAs steam from the reservoir released, it is used to rotate a turbine, after sending the steam through a rock-catcher. The rockcatcher protects the turbine from rocks which come along with the steam.

Hybrid power plant: - • Some geothermal fields produce boiling water as well as

Hybrid power plant: - • Some geothermal fields produce boiling water as well as steam, which are also used in power generation. • In this system of power generation, the flashed and binary systems are combined to make use of both steam and hot water. • Efficiency of hybrid power plants is however less than that of the dry steam plants.

The Industry and Market Trends: - ØTotal investment in geothermal energy from 1973 to

The Industry and Market Trends: - ØTotal investment in geothermal energy from 1973 to 1995 was about US$22 billion, and the industry continues to grow at about 16 percent per annum in electricity generation and about 6 percent in direct uses. ØIf present trends continue, geothermal electricity generating capacity could increase from about 10, 000 MW at the start of 2000, to 58, 000 MW in 2020.

Trends in U. S. & international Geothermal Investments (2006 -2009)

Trends in U. S. & international Geothermal Investments (2006 -2009)

GEOTHERMAL USES, 2008 - 2009 • Power generation Nesjavellir power plant, Iceland Ø- Installed

GEOTHERMAL USES, 2008 - 2009 • Power generation Nesjavellir power plant, Iceland Ø- Installed capacity: 9. 7 Gwe ØProduction: 60 TWh Ø 24 countries; 5 produce 15 -22% of electricity from geothermal (Costa Rica, El Salvador, Iceland, Kenya, the Philippines). ØR&D to use 87 - 120ºC water to generate electricity in binary schemes (0. 3 -3 MWe) – USA, Austria, Germany, Iceland • Direct uses: Ø Installed capacity: 27 825 MWe, Ø Production: 261 418 TJ/2005 Ø 50% for heating (GHGs limitation!) for 72 countries Ø 2000 – 2004: 50% increase of installed capacity and heat use Geothermal spa, Iceland

Trends in geothermal energy A case study on TURKEY ØUnlike the world trend, utilization

Trends in geothermal energy A case study on TURKEY ØUnlike the world trend, utilization of heat pumps and development of enhanced geothermal systems have not gained any footage in Turkey. ØHeat pump utilization is very limited due to its high capital costs. Carbon credit’s exchange may not be feasible given the high CO 2 content of most of Turkey’s high enthalpy geothermal resources. ØOn the other hand, geothermal power plants and greenhouse heating seem to be very popular for the private sector.

Economics of geothermal Power Generation in Turkey: - ØA stochastic study was conducted on

Economics of geothermal Power Generation in Turkey: - ØA stochastic study was conducted on economics of geothermal resources in Turkey (Serpents, 2005). ØAs for electricity generation, this type of utilization looks profitable with the electricity selling prices of around 6 cents/k. Wh. ØThe payout time for this type of investments reaches 7 to 8 years. ØThe profitability increases with the quality (heat content) of resource and the magnitude (physical extent) of resources

Why Our Geothermal Resources Have Not Been Properly Developed There are many problems hindering

Why Our Geothermal Resources Have Not Been Properly Developed There are many problems hindering the development of geothermal resources of Turkey. These can be summarized in 3 categories: Ø technical, Ø economical, and Ø legislative