Geothermal energy resources of Azerbaijan

he Republic of Azerbaijan has rich geothermal energy potential. For the assessment of these deposits, all geothermal deposits located in the territory of the Republic have been identified and specific information has been collected about these deposits. A data bank for geothermal deposits is currently being prepared. The assessment of geothermal deposits existing in Azerbaijan will help to identify areas suitable for the use of electricity. Considering that 3 km depth is conventionally accepted as the limit for hydrothermal systems, the amount of heat accumulated within the territory of Azerbaijan was estimated using temperature gradient maps. In order to create an inventory of existing hydrothermal resources, all geothermal wells, vents, hot springs were evaluated and the apparent capacity was calculated taking into account flow rates. The available hydrothermal resource potential of Azerbaijan consists of two components: identified and prospective reserves. Hydrogeological studies of the thermal waters of Azerbaijan have made it possible to determine vertical and layered hydrogeochemical zonation. As the sediments of the foothills of the Lesser and Greater Caucasus are deposited, changes in mineralisation and hydrochemical types occur. Fresh, hydrocarbonate-calcium waters are gradually replaced by saline, hydrocarbonate-sodium and sodium-chloride waters. Fresh waters are found almost at a depth of 400-450 metres (in Absheron and somewhere in Agchagil sediments), excepting the Absheron Peninsula and South-Eastern Shirvan. Here, at the surface, the waters are very saline and contain calcium chloride. Deep waters (Maikop, Cretaceous, Jurassic) are more mineralised (8-20 and sometimes up to 100 g/l and contain sodium chloride. Weakly mineralised thermal nitrogen-hydrogen-sulphur thermal waters of the folded mountainous regions of the Greater Caucasus have a hydrocarbonate-sodium-magnesium composition. In the Lesser Caucasus, carbonate, hydrocarbonate-sulphate-chloride-magnesium waters are more mineralised (4-5 g/l). In the Lesser Caucasus, carbonated, hydrocarbonate-sulphate-chloride-magnesium waters are highly mineralised (4-5 g/l). Thermal waters of the mountainous Talish and the Lenkaran plains are highly mineralised (17-35 g/l), with chloride-sodium-nitrogen-methane content.