Geothermal Potential and First Achievements of its Utilization in Lithuania

Abstract

The territory of Lithuania is in the marginal area of the western part of the Precambrian East European platform. Main tectonic elements in Precambrian crystalline basement are the Baltic Syneclise and its slope, the Masurian-Belarusan Anteclise, and the Latvian Saddle. The western part of Lithuania is characterized by 40km depth, but central part - by 44-47km average depths of Mocho surface. It was also established that the specified large geoblocks in the structure have number of deep faults (penetrating as deep as mantle) with a significant subvertical amplitude of displacement in the deep strata, but it was insignificant on the surface. The increased geothermal parameters are typical in western part of Lithuania with heat flow about 100 mW/m2.
The geothermal potential of Lithuania was estimated for three regional hydrogeothermal complexes: Cambrian (5.1x1018J), Lower-Middle Devonian (5.0x1018J), Middle-Upper Devonian 1.5x1018J). Petrogeothermal resources were estimated down to 7km depth in Lithuania (7x1021J).
Usage of geothermal resources for district heating started at 2000. The first geothermal demonstration plant in Lithuania was built in Klaipeda. Total thermal capacity of plant - 41MW. Low-temperature geothermal heat is extracted from geothermal water (38?C pumped from 1100 m depth) using absorption heat pump. Amount of heat produced by plant in year 2003 was - 215000 MWh.
In spite of technical problems Klaipeda Geothermal Demonstration Plant is reliable heat supplier capable to participate in competition with traditional heat suppliers.
Geothermal investigations were performed by the German company Geothermie Neubranderburg GmbH for sites of Vydmantai, Vilkaviskis and Silute.
Potential consumers of the Earth's thermal energy are several cities and towns (Palanga, Kretinga, Plunge, Gargzdai, Nida, Silale) and numerous settlements situated in area of the West Lithuanian Geothermal Field.
More than 200 systems of ground-source heat pumps are installed for heating at single family houses (total capacity - more than 3MW).