Geothermal Energy

What is geothermal energy, and how does it work?
Geothermal energy is heat that exists within the earth's crust. Geothermal is derived from the Greek words geo (earth) and therme (heat) (heat). Because heat is constantly produced inside the earth, geothermal energy is a renewable energy source. Geothermal heat is used for bathing, heating houses, and generating energy.

Geothermal energy is derived from the earth's interior
Geothermal energy is created by the slow disintegration of radioactive particles in the earth's core, a process that occurs in all rocks. The earth is divided into four primary layers:

• A solid iron inner core with a circumference of around 1,500 kilometres
• A 1,500-mile-thick layer of hot molten rock known as magma surrounds the planet.
• The outer core is surrounded by a 1,800 mile thick mantle of magma and rock.
• The continents and ocean floors are formed by a solid rock crust that is 15 to 35 miles thick beneath the continents and 3 to 5 miles thick beneath the oceans.

Geothermal energy is created by the slow disintegration of radioactive particles in the earth's core, a process that occurs in all rocks.

The temperature of the earth's inner core has been discovered to be around 10,800 degrees Fahrenheit (°F), which is as hot as the sun's surface. Temperatures in the mantle range from around 392°F at the earth's crust's upper limit to roughly 7,230°F at the mantle-core boundary. Tectonic plates are the shattered parts of the earth's crust. Many volcanoes form near the borders of these plates, where magma gets close to the earth's surface.

Volcanic lava contains a little amount of magma. Magma heat is absorbed by rocks and water deep beneath. The hottest temperatures are found in the rocks and water located farther beneath.

History

Cooking, bathing, and heating have all been done with geothermal energy from hot springs and natural pools for centuries. Native Americans may have used geothermal energy for cooking as early as 10,000 years ago. Baths heated by hot springs were utilised by the Romans and Greeks in ancient times. Traces of geothermal room heating may be found as early as the 1st century CE at the Roman city of Pompeii. Initially, geothermal energy applications were confined to areas with access to hot steam and water.

Uses

Direct-use applications, geothermal heat pumps (GHPs), and electric power generation are the three types of geothermal energy applications.

1. Direct applications

• Heated water is extracted directly from the ground without the use of any additional equipment.
• Low-temperature geothermal resources, ranging between 50 and 150 °C (122 and 302 °F), are used in direct-use applications.
• Low-temperature geothermal water and steam have been utilised to heat buildings and entire districts from a single source.
• In addition, geothermal resources have been used to heat many swimming pools, balneological facilities at greenhouses, spas, and aquaculture ponds around the world.
• Cooking, industrial applications (such as vegetables, drying fruits, and lumber), milk pasteurisation, and large-scale snow melting are all direct uses of geothermal energy.
• Hot water is frequently used in the heating system for many of these operations, or it may be used in conjunction with a heat exchanger. It transfers heat when the fluid contains troublesome minerals and gases such as hydrogen sulphide.

2. Heat pumps that use geothermal energy

• GHPs use the relatively moderate temperature conditions that occur within the first 300 metres (1,000 feet) of the surface to heat and cool buildings in the winter and summer, respectively.
• Rocks and groundwater in that area of the lithosphere have temperatures ranging from 5 to 30 degrees Celsius (41 to 86 degrees Fahrenheit).
• The temperature of the ground maintains a constant temperature of 10 to 16 °C (50 to 60 °F) at shallower depths, where most GHPs are located, such as within 6 metres (approximately 20 feet) of the Earth's surface.
• As a result, during winters, when the air temperature falls below that of the ground, that heat can be used to help warm buildings
• Similarly, warm air can be extracted from a structure and pumped underground.There it loses much of its heat and is restored during the warmer months of the year.

3. Generating electricity

• Geothermal energy can be used to generate power depending on the temperature and fluid flow.
• There are three methods that geothermal power plants can generate electricity. Regardless of their architectural differences. All three control the behaviour of steam and use it to power electrical generators.
• Geothermal power is considered a renewable energy source since the extra water vapour at the end of each process is condensed and returned to the ground, where it is reheated for further use.
• The heated water vapour is channelled directly into a turbine that operates an electrical generator in such "dry steam" operations.
• Other power plants, dependent on the flash steam and binary cycle designs, start the electrical generating process using a mixture of warm water and steam ("wet steam") retrieved from the ground.