geothermal energy

The word geothermal comes from the Greek words geo (earth) and therme (heat). So, geothermal energy is heat from within the earth. We can use the steam and hot water produced inside the earth to heat buildings or generate electricity. Geothermal energy is a renewable energy source because the water is replenished by rainfall and the heat is continuosly produced inside the earth.

Geothermal energy is generated in the earth's core, about 4,000 miles below the surface. Temperatures hotter than the sun's surface are continuously produced inside the earth by the slow decay of radioactive particles, a process that happens in all rocks. The earth has a number of different layers

The core itself has two layers: a solid iron core and an outer core made of very hot melted rock, called magma

The mantle which surrounds the core and is about 1,800 miles thick. It is made up of magma and rock


The crust is the outermost layer of the earth, the land that forms the continents and ocean floors. It can be three to five miles thick under the oceans and 15 to 35 miles thick on the continents.


The earth's crust is broken into pieces called plates. Magma comes close to the earth's surface near the edges of these plates. This is where volcanoes occur. The lava that erupts from volcanoes is partly magma. Deep underground, the rocks and water absorb the heat from this magma. The temperature of the rocks and water get hotter and hotter as you go deeper underground.
People around the world use geothermal energy to heat their homes and to produce electricity by digging deep wells and pumping the heated underground water or steam to the surface



Most geothermal reservoirs are deep underground with no visible clues showing above ground.

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  volcanoes and fumaroles (holes where volcanic gases are released)
  
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  hot springs and
  
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  geysers.
  
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  The most active geothermal resources are usually found along major plate boundaries where earthquakes and volcanoes are concentrated. Most of the geothermal activity in the world occurs in an area called the Ring of Fire. This area rims the Pacific Ocean
  

When magma comes close to the surface it heats ground water found trapped in porous rock or water running along fractured rock surfaces and faults,Such hydrothermal resources have two common ingredients: water (hydro) and heat (thermal). Naturally occurring large areas of hydrothermal resources are called geothermal reservoirs. Geologists use different methods to look for geothermal reservoirs. Drilling a well and testing the temperature deep underground is the only way to be sure a geothermal reservoir really exists.


electricity generation
geothermal heat pumps
planting


The direct use of hot water as an energy source has been happening since ancient times. The Romans, Chinese, and Native Americans used hot mineral springs for bathing, cooking and heating. Today, many hot springs are still used for bathing, and many people believe the hot, mineral-rich waters have natural healing powers



After bathing, the most common direct use of geothermal energy is for heating buildings through district heating systems. Hot water near the earth's surface can be piped directly into buildings and industries for heat. A district heating system provides heat for 95 percent of the buildings in Reykjavik, Iceland. Examples of other direct uses include: growing crops, and drying lumber, fruits, and vegetables

While temperatures above ground change a lot from day to day and season to season, temperatures in the upper 10 feet of the Earth's surface hold nearly constant between 50 and 60 degrees Fahrenheit. For most areas, this means that soil temperatures are usually warmer than the air in winter and cooler than the air in summer. Geothermal heat pumps use the Earth's constant temperatures to heat and cool buildings. They transfer heat from the ground (or water) into buildings in winter and reverse the process in the summer

Direct use and heating applications have almost no negative impact on the environment,
Geothermal power plants do not burn fuel to generate electricity, so their emission levels are very low. They release about 1 to 3 percent of the cabon dioxide emissions of a fossil fuel plant. Geothermal plants use scrubber systems to clean the air of hydrogen sulfide that is naturally found in the steam and hot water. Geothermal plants emit 97 percent less acid rain - causing sulfur compounds than are emitted by fossil fuel plants. After the steam and water from a geothermal reservoir have been used, they are reinjected back into the earth.

Thx good job & go ahead
السكندرى حتى النخاع
محمد وجدى
Z35