The possibilities of diverse use of geothermal energy in Lithuania

Abstract

Lithuanian??s territory with regard to its geology and tectonics belongs to the western edge of the Precambrian East European platform. The sedimentary formations (from Vendian upto Quaternary) lie ontop of the Precambrian basement rocks. According to the depth of basement three large tectonic structures are determined in the territory of Lithuania: the Baltic Syneclise (Craton) and its slope, the Mosurian-Belarusian Anteclise, and the Latvian Saddle. Research of geothermal energy started in 1988. First of all (since year 1994) the shallow geothermal resources have been used in developing individual heating systems with heat pumps. The geothermal resources up to 100 meters depth are very attractive. It is very easy to use: they are spread everywhere and are renewable. The main deep-hydrothermal resources are related to aquifers of regionalCambrian and Devonian. Usage of geothermal resources from Devonian for the centralize heating started at 2000. The first geothermal demonstration plant in Lithuania was built in Klaipeda. The total capacity is 41 MW. Two production and two injection wells were drilled. The geothermal water (38 o C and salinity ~98 g/litre) is pumped from1100 m depth. Petrothermal resources are related to the Hot Dry Rocks (the temperature is 150-180 o C at the depth 4-5 km). The legal and economical-technical problems hinder realization of usage of geothermal energy in Lithuania.