I charged my mobile phone by geothermal energy, which was produced in a geothermal power plant.

The geothermal energy is a natural demonstration of a thermal energy of the Earth´s core. This energy is shown by the eruption of volcanoes and geysers, hot springs or steam emissions. This energy is used in a form of thermal energy (for heating) or for production of electric power in geothermal power plants. It usually belongs among renewable sources of energy, but it doesn´t always have to be truth. Some sources of geothermal energy can be exhausted within a period of next decades of years.

The geothermal power plants use the energy of the Earth´s core, which is gained from the deep wells inside the Earth. From these well is gained the steam or hot water.  The possibility of a building a power plant is dependent on tectonic conditions in the locality. Geothermal energy is often connected with a volcanic activity, which leads in high requirements to the construction of a power plant in seismic active areas.