Geothermal powerGeothermal power

Earth‘s power harvestedEarth‘s power harvested

Geothermal powerGeothermal power

• Geothermal power is energy generated by heat Geothermal power is energy generated by heat stored beneath the Earth's surface. stored beneath the Earth's surface.

• The first geothermal generator was tested on 4 The first geothermal generator was tested on 4 July 1904, at the Larderello dry steam field in July 1904, at the Larderello dry steam field in Italy.Italy.

• The largest group of geothermal power plants in The largest group of geothermal power plants in the world is located in The Geysers, a geothermal the world is located in The Geysers, a geothermal field in California.field in California.

• As of 2007, geothermal power supplies less than As of 2007, geothermal power supplies less than 1% of the world's energy.1% of the world's energy.

ContentsContents

• 1 Electricity generation 1 Electricity generation – Dry Steam Power Plants Dry Steam Power Plants – Flash steam Power Plants Flash steam Power Plants – Binary-cycle Power Plants Binary-cycle Power Plants

• 2 Geothermal energy usage 2 Geothermal energy usage

• 3 Advantages 3 Advantages

• 4 Disadvantages 4 Disadvantages

Electricity generation Electricity generation

• There are three different types of power plants There are three different types of power plants

– dry steamdry steam – flashflash – binarybinary

Dry Steam Power Plants Dry Steam Power Plants

– A dry steam power plant uses dry steam .A dry steam power plant uses dry steam .– Dry steam is steam that contains no water Dry steam is steam that contains no water

droplets .droplets .– Typically above 235°C Typically above 235°C – Dry steam plants are used where there is Dry steam plants are used where there is

plenty of steam available that is not mixed plenty of steam available that is not mixed with water. with water.

– Dry steam plants are the simplest and most Dry steam plants are the simplest and most economical of geothermal plants. economical of geothermal plants.

Flash steam Power PlantsFlash steam Power Plants

– A Flash steam power plant uses hot water.A Flash steam power plant uses hot water.– Typically above 182 °CTypically above 182 °C– The high pressure underground keeps the The high pressure underground keeps the

water in the liquid state, although it is well water in the liquid state, although it is well above the boiling point of water at normal sea above the boiling point of water at normal sea level atmospheric pressure.level atmospheric pressure.

– As the water is pumped from the reservoir to As the water is pumped from the reservoir to the power plant, the drop in pressure causes the power plant, the drop in pressure causes the water to convert, or "flash", into steam to the water to convert, or "flash", into steam to power the turbine.power the turbine.

– Flash steam plants are the most common type Flash steam plants are the most common type of geothermal power generation plants in of geothermal power generation plants in operation today.operation today.

Binary-cycle Power PlantsBinary-cycle Power Plants

– The water used in binary-cycle power plants is The water used in binary-cycle power plants is cooler than that of flash steam plants.cooler than that of flash steam plants.

– From 107 to 182 °CFrom 107 to 182 °C– The hot fluid from geothermal reservoirs is The hot fluid from geothermal reservoirs is

passed through a heat exchanger which passed through a heat exchanger which transfers heat to a separate pipe containing transfers heat to a separate pipe containing fluids with a much lower boiling point (ios-fluids with a much lower boiling point (ios-butane or iso-pentane) which are vaporized to butane or iso-pentane) which are vaporized to power the turbine .power the turbine .

– The advantage to binary-cycle power plants is The advantage to binary-cycle power plants is their lower cost and increased efficiency.their lower cost and increased efficiency.

Geothermal energy usageGeothermal energy usage

• IcelandIceland– The Svartsengi Power-Plant , The Nesjavellir Power-Plant, The Svartsengi Power-Plant , The Nesjavellir Power-Plant,

The Krafla Power-Plant The Krafla Power-Plant

• United StatesUnited States– there were 75 new geothermal power projects underway there were 75 new geothermal power projects underway

in 12 states as of May 2007 and are currently present in in 12 states as of May 2007 and are currently present in Alaska, California, Hawaii, Nevada, and UtahAlaska, California, Hawaii, Nevada, and Utah

• New ZealandNew Zealand– Kawerau geothermal power station is a 90-Kawerau geothermal power station is a 90-

megawatt geothermal power plant now under megawatt geothermal power plant now under constructionconstruction

Advantages Advantages

• It‘s clean and safe for the surrounding It‘s clean and safe for the surrounding environment.environment.

• It is also sustainable because the hot water used It is also sustainable because the hot water used in the geothermal process can be re-injected into in the geothermal process can be re-injected into the ground to produce more steam. the ground to produce more steam.

• From an economic view, geothermal energy is From an economic view, geothermal energy is extremely price competitive in some areas and extremely price competitive in some areas and reduces reliance on fossil fuels and their inherent reduces reliance on fossil fuels and their inherent price unpredictability. price unpredictability.

DisadvantagesDisadvantages

• Construction of the power plants can adversely Construction of the power plants can adversely affect land stability in the surrounding region.affect land stability in the surrounding region.

• Dry steam and flash steam power plants also emit Dry steam and flash steam power plants also emit low levels of carbon dioxide, nitric oxide, and low levels of carbon dioxide, nitric oxide, and sulfur, although at roughly 5% of the levels sulfur, although at roughly 5% of the levels emitted by fossil fuel power plants .emitted by fossil fuel power plants .

We thank you!We thank you!

• Made by :Made by :– Adascalitei VictorAdascalitei Victor– Coman AndreiComan Andrei– Oaida AdrianOaida Adrian

• Coordinated by :Coordinated by :– Schnabel DieterSchnabel Dieter