DOI: 10.5593/sgem2017/42/S17.085


K. Prill, M. Szczepanek
Tuesday 12 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-07-2 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 42, 683-690 pp, DOI: 10.5593/sgem2017/42/S17.085


According to the literature [9,15] geothermal energy means a part of the Earth’s energy resources accumulated in water, water steam and dry hot rocks. It is classified to a group of renewable resources, virtually inexhaustible due to its transfer from the Earth’s inside by conduction and convection. M. Kaczmarczyk [6] describes geothermal energy as a primary energy originated in the process of the Earth formation and as the energy generated by the radioactive decay. It has been evaluated that the global geothermal energy resources equal to around 8 1030J [5], while at the depth of 5,000 the resources amount to 1,4 1 026 J. Geothermal energy has also been classified in terms of its source. The classification includes two groups. The first group includes hydrothermal energy resources such as, in particular, underground watercourses containing diluted minerals (NaCl, KCl, CaCl2, SiO2) and gasses (mostly CO2, N2). The latter one comprises of petrothermal energy resources among which there is the dry layer of rocks and salt domes [13].

Taking into consideration the temperature, the geothermal energy sources may be classified as [10,14,15]:

- Lower - temperature sources, where the water temperature is < 90 °C,
- Medium - temperature sources, where the water temperature is from 90 °C to 150 °C,
- High - temperature sources, where the water temperature is >150 °C.

Keywords: geothermal energy, generation of energy, electricity, geothermal power station, renewable energy resources,