What is Geothermal Energy: Its Working and Use in Buildings

Madeh Izat Hamakareem

3 months ago

Reading time: 1 minute

Geothermal energy is a form of renewable energy that originates from the subsurface of the earth. The reservoirs of hot water and steam present at various temperatures and depths below the ground are the source of geothermal energy. These reservoirs were formed during the formation of the earth.

The underground geothermal reservoirs can be reached through drilling wells with a minimum depth of one mile. This form of renewable energy is harnessed and prepared to be used at geothermal power plants. It has various applications like electricity generation, heating, and cooling.

Geothermal energy is cleaner, more efficient, and cost-effective than fossil fuel. Since the power is produced close to the plant, it cuts processing and transportation costs. In addition, it is continuously used regardless of weather conditions.

Contents:

What is Geothermal Energy?
How is Geothermal Energy Generated?
Geothermal Applications
Advantages of Geothermal Energy
FAQs

What is Geothermal Energy?

Geothermal power is a type of renewable energy which is stored in the fluid and rocks of the earth’s core. It can be harnessed by drilling a mile or more deep well into the underground reservoir to reach the hot fluid and steam, stimulating turbines linked to the electricity generator.

How is Geothermal Energy Generated?

Geothermal energy is commonly generated in geothermal plants. The first profitable geothermal power plant was launched in 1960 in the United States. Currently, more than 60 geothermal power plants are operating in the US.

Geothermal power plants are of three types: dry steam, flash, and binary, which is the most recent one and advanced type.

Dry Steam

Dry steam geothermal energy plant uses the oldest type of geothermal technology which brings out underground steam to the surface and utilizes it for driving turbines.

Flash Steam Plant

Flash steam plant takes high-pressure hot water out from underground and converts it into cold and low-pressure water which is used for powering turbines. Water and air pollution due to geothermal energy mostly comes from flash steam plants.

Binary Plant

The binary plant passes hot water through a secondary liquid with a lower boiling point that turns into vapor to drive turbines.

Geothermal Applications

As soon as the geothermal energy reaches the surface, it can be used for various applications based on its heat.

The underground geothermal reservoir of hot fluid and steam can be used for electricity generation and other heating and cooling applications like a geothermal heat pump.

The heat pumps cool buildings in summer and heat them during winter seasons. In addition, the geothermal energy can be piped under roads and sidewalks to melt snow on roads. It can also be directly utilized for district heating and home businesses.

Figure-5: Applications of Geothermal Energy Based on its Degree of Heat

Advantages of Geothermal Energy

1. Renewable Energy

Geothermal power is renewable energy if the reservoir is properly managed, i.e., the energy extraction rate is balanced with the natural recharge rate of the reservoir.

2. Clean

The most developed geothermal power plant, which is closed-loop, does not emit greenhouse gases. It uses less water on average over the lifespan of the plant compared to other conventional energy sources. Geothermal energy can be extracted without burning fossil fuels like water, gas, and oil.

3. Economy

Geothermal energy is fairly cheap. Direct use of geothermal energy leads to the cost reduction of about 80% over fossil fuel.

4. Baseload

Geothermal energy offers a continuous supply of electricity regardless of weather conditions.

5. Domestic

Countries with geothermal reservoirs can produce electricity without buying and importing energy.

6. Small Footprint

The geothermal power plant requires a smaller area per GWh (404 m²) compared with solar PV with a central station (3237 m²), wind (1335 m²), or coal (3642 m²).