Geothermal Energy

By: Sahil Minhas

What is Geothermal Energy?

Geo means Earth, thermal means heat. Geothermal energy is the heat from the Earth. Resources that can be used as Geothermal energy can range from shallow ground to hot water and rocks found a few miles beneath the Earth's surface, and down even deeper to high temperatures of molten rock called magma.
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How can we use it?

There are three main ways that Geothermal energy can be used. Direct geothermal energy, Geothermal heat pump, and Geothermal power plant.

~ Direct geothermal energy

Direct geothermal energy: In areas with hot springs or geothermal reservoirs are near the Earth's surface, hot water can be piped in directly to heat homes or office buildings. Geothermal water is pumped through a heat exchanger, which transfers the heat from the water into the building's heating system. The used water can be sent back down a well into the reservoir to be reheated and used again.
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~ Geothermal heat pump

A few feet under the ground the soil remains a constant 10 -15 degrees Celsius. Which is enough to be used to heat or cool homes and offices. The fluid circulated through a series of pipes (called a loop) under the ground. An electric compressor and heat exchanger pull the heat from the piped and send it through a duct system around the building. For cooling the pipes draw heat away form the heat and carry it to the ground outside, where it gets absorbed.
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~ Geothermal power plant

Hot water and steam from deep underground can be piped up through underground wells and used to generate electricity in a power plant. There are three different types or Geothermal power plants.

- Dry steam plants: Hot steam is piped into generators in the power plant from geothermal reservoirs. The steam spins turbines, in turn generating electricity.

- Flash steam plants: Water that's around 150 - 400 degrees Celsius is brought up through a well. Some of the water turns into steam, which drives the turbines and when the steam cools it condenses back into water and returns to the ground.

- Binary cycle plants. Moderately hot geothermal water is passed through a heat exchanger, where its heat is transferred to a liquid that boils at a lower temperature than water. When the fluid is heated enough and eventually turns into steam it spins the turbines.

Geothermal energy compared to other energy sources.

Geothermal energy compared to other energy sources is more efficient, cleaner, and cost-effective than burning fossil fuels. This source of energy is cleaner because it can be generated without the burning of fossil fuels. Geothermal plants only release a fraction of carbon dioxide fossil fuel plants release and create very little amounts of nitrous oxide or sulfur gas.

Geothermal energy is created right next to the plant so money is saved on processing and transportation costs. Also being more reliable as they run 24/7. Geothermal plant costs are usually high ranging from $1 to $4 million for each well to drill. The installation of a home geothermal pump system can be as much as $30,000, but can cut the energy bill by 30 to 40 percent, eventually paying itself off by 5-10 years.

Geothermal energy is renewable because the heat is continually replaced as the water that is removed is put back into the ground after being used. They are the best option because it can be used anywhere in the world because the temperature in the ground remains constant.

Geothermal Energy and Connections

Geothermal energy does little to no damage to the environment, the steam and water contain natural traces of hydrogen sulfide and other gases and chemicals with high concentration. Geothermal power plants have "scrubbers" that clean the air of hydrogen sulfide and other gases. Geothermal plants do not burn fuels top generate electricity and release less than 1 to 4 percent of the amount of carbon dioxide (CO2) emitted from coal plants.