Geothermal energy refers to energy derived directly or indirectly from chemicals, hot water and steam generated from heat stored at different depths of the earth's crust. Depending on its characteristics, geothermal energy can be used for heating and cooling or for the production of green electricity. The fact that thermal waters have groundwater energy storage properties and a high heat and energy capacity testifies to their special importance among renewable energy sources.
Geothermal energy’s technologies
There are different geothermal technologies with different levels of development in the world, which are widely used in central heating systems, greenhouses and other applications. The technology of generating electricity from naturally high-conductivity hydrothermal tanks is also considered reliable. Most of the geothermal power plants currently in operation in the world are based on dry steam turbines or "flash" devices (single, double and triple) and are used in 180 °C above hot water sources. In addition, new technologies are being developed, such as Enhanced Geothermal Systems (EGS).
Use of geothermal energy
Depending on the type and temperature of geothermal water, there are three main uses:
- Electricity generation (by driving a geothermal water vapor turbine);
- Heating energy production;
- Used for balneological health (treatment) purposes.
While high and very high thermal waters are suitable for the production of electricity and heat, thermal and low thermal waters are only suitable for the production of thermal energy. Mineral water is used to treat a number of diseases.
In order to use geothermal waters as alternative energy sources, the study of the composition of these waters is one of the main factors in the study of their thermal and physical properties. One of the important conditions here is the chemical analysis of water, the study of the geological structure of the springs.
Geothermal energy worldwide
Geothermal energy is currently the least used renewable energy source in the world. According to the REN21 Global Status Report, the installed capacity of geothermal power plants in the world in 2020 was only 0.1 GW, most of which was installed in Turkey. The total installed capacity of geothermal energy is 14 GW.
According to the International Renewable Energy Agency (IRENA), the top five countries in the world by the installed capacity of the geothermal energy are the United States (2 GW), Indonesia (2 GW), the Philippines (1 GW), Turkey (1 GW) and New Zealand (984 MW).
Electricity produced from geothermal energy is provided to only 1% of the world's population, while the Earth's geothermal energy potential is strong enough to meet the energy needs of all people on earth. The high cost of drilling and exploration is one of the factors hindering the realization of this potential.