Geothermal Energy Country Update - Lithuania

Abstract

ABSTRACT Lithuania is situated in the western periphery of the East European Craton (EEC) that was consolidated during the Archean and Proterozoic. This type of the geotectonic structures is characterized by a low intensity geothermal field owing primarily to a low tectonic activity. There is an exceptional high heat flow anomaly mapped in west Lithuania that is the most intense in the EEC. The heat flow is as high as 70-95 mW/m2, while the background value of the craton is assessed about 40 mW/m2. The origin of the anomaly is related to the Middle Proterozoic hot granites hosted by the Lower Proterozoic metamorphic rocks composing the basement of the Baltic sedimentary basin. Some activity is also suggested bellow the Earth’s crust of west Lithuania at the mantle level. There are several large geothermal aquifers identified in the sedimentary pile of the basin. The Middle Cambrian and the Lower Devonian sandstones are considered as the most prospective low enthalpy geothermal reservoirs. The temperatures reach 70-95oC and 35-45oC in the Cambrian and Devonian aquifers, respectively. The depths are, respectively, about 2 km and 1 km. Also, the Middle Devonian reservoir (30-35oC) is considered as a prospective body when combined to the balneological applications. The information on the situation of Klaipeda geothermal demonstration plant (KGDP) and the growth of installed capacity of ground-source heat pump systems are presented in the paper. Two case studies, as good practice examples of Lithuania, are also discussed: First - the logistics center of the Lithuanian company SANITEX in Riga is presented. For the 40000 m2 warehouse with refrigerators - the 700 kW heat pump ground source system with a drilled probe field under the building is implemented. The field of drilled probes is regenerated by the heat extraction from food refrigeration equipment. The heat pump ground source system fully covers the heating, hot water and ventilation needs in the building with Seasonal Performance Factor (SPF) more than 5 of heat pumps. Second - the first re-circulating marine aquaculture system for shrimp cultivation was established in Klaipeda as a part of the EU South Baltic projects InnoAquaTech and Baltic Blue Biotechnology Alliance. The system of eight tank, 40 m3 is designed to grow up white-leg shrimps. The task of this pilot project is to carry out shrimp growing experiments, to obtain knowledge and competences, to get expertise in marine re-circulating aquaculture technology, and transfer these competences to the aquaculture business.