An assessment of technical and economic feasibility to install geothermal well systems across Ukraine

Abstract

Although the resources of geothermal energy in Ukraine greatly exceed domestic conventional energy sources, using geothermal heat in the country is still far behind the existing opportunities. Addressing this gap requires a large-scale pre-feasibility assessment with proper account for hydrogeological and economic factors to facilitate identifying the most promising areas of the country for efficient use of geothermal energy. One of the well-known technologies in this field is a geothermal well system (GWS) that combines pumping out thermal waters, extracting heat on the ground, and reinjecting cooled water back to the aquifer. In this study, we created the maps of expected thermal output and profitability of the doublet GWS across Ukraine for minimum and maximum values of depth and flow rate of thermal waters applying analytical methods of heat transfer in saturated rocks in combination with the net present value (NPV) as a generally accepted economic criterion. Map analysis showed that the GWS maximum expected thermal output might reach 5–9 MW in the Black Sea coastal area and steppe Crimea at the flow rate exceeding 1500 m3/day and aquifer depth of 2 km and more. The NPV index is positive for the most part of Ukraine and increases up to 7–17 million € in southern regions of the country. Calculating performance parameters for two potential GWS sites showed a higher thermal output for a GWS in the Black Sea coastal area compared to the site in Transcarpathia but comparable NPV for both sites due to lower installation costs in the western part of the country.