The most active geothermal resources are generally found along the boundaries of the main tectonic plates, where most volcanoes are located. One of the most active geothermal areas in the world is called the Ring of Fire, which surrounds the Pacific Ocean. Geothermal energy is natural and renewable, and a large number of countries around the world use it for industrial and domestic processes. However, the efficiency of these plants depends on how suitable the area in which they are located is for energy production.
This suitability is a complex combination of geophysical factors, largely still unknown. To date, studying the suitability of an area for the construction of a geothermal power plant requires invasive inspections, drilling, related permits and authorizations, and large costs. In addition, citizens involved in the fields of inspections and construction are rightly calling for transparency about the reasons for choosing their territory for the construction of a power plant and about the benefits and problems, ecological and social, that this may entail. Geothermal energy is the heat that comes from the Earth's subsurface.
It is contained in rocks and fluids found beneath the Earth's crust and can even be found in the Earth's hot molten rock, magma. Italy was a pioneer in the use of geothermal resources with the first geothermal plant that began in 1904. Geothermal heat pumps regulate temperature by exchanging subsurface air, which is cooler than surface air in summer and warmer in winter, with air inside the building. In recent decades, there have been many advances in geothermal technology that expand the range of possible resources for geothermal use. The country, which describes itself as a “pioneer” of geothermal energy, produces 25% of its energy in five geothermal power plants.
Geothermal power plants are no exception; however, instead of burning oil or coal to generate heat, they obtain heat from the hot water inside the Earth itself. In addition to improved geothermal systems, other emerging geothermal uses are allowing the use of resources that were not previously widely used, such as low-temperature and co-produced resources. Water from hydrothermal reservoirs (often at a temperature lower than that needed for other types of geothermal power plants) to heat another working fluid with a much lower boiling point. Improved geothermal systems (EGS) use geothermal resources that come from much deeper deposits than the systems mentioned above.
In addition to electricity generation, geothermal energy applications include temperature control (both for heating and cooling) and industrial processes. The United States is the world's largest producer of geothermal energy and is home to the largest geothermal field. Iceland is one of the countries with the highest percentage of public energy generation and heating from geothermal energy. Geothermal systems are also used in industrial environments where heat is an essential component of a process, such as the pasteurization of milk or the dehydration of food.
Since water heat is the essential component of a geothermal power plant, these active systems are usually located where hydrothermal deposits exist.