Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser Capacities and energy potential of thermal-mineral springs in the area of the Kopaonik tourist region (Serbia) Dušan Ristić a, ⁎ , Danijela Vukoičić a , Milena Nikolić a , Miroljub Milinčić b , Dušan Kićović c a Faculty of Natural Sciences and Mathematics, University of Priština, Ivo Lole Ribara 29, 38220 Kosovska Mitrovica, Serbia b Faculty of Geography, University of Belgrade, Studentski trg 3/3, 11000 Belgrade, Serbia c Ministry of Education, Science and Technological Development, Zahumska 14, 11000 Belgrade, Serbia ARTICLE INFO Keywords: Thermal-mineral springs Energy potential Geothermal energy Kopaonik region Serbia ABSTRACT In the Kopaonik tourist region of Serbia, there are numerous thermal-mineral (TM) springs with an outlet temperature which ranges from 21 to 78.7 °C. The main objective of the study is to determine the capacities, thermal power and energy potential of 19 TM springs in 4 spas of this region. This study supports the hypothesis that in the Kopaonik tourist region, TM springs have considerable capacity, as well as heat power and energy potential. The modern method for determining the energy potential and heat power, based on the fow rate, the inlet and outlet temperatures of the TM springs, was applied in the region with rich geothermal sources, and the obtained results were converted to the fossil fuel energy. The research of the given region, using the above method, is more detailed than the previous research carried out at the national level, so the results are more reliable and suggest that similar research should be carried out at the regional and local level. The estimated total heat energy is 758.51 TJ/year, and heat power (capacity) is 24.1 MWt. The TM springs of this region make up 9.06% of the estimated geothermal energy of Serbia and 7.53% of the estimated heat power. The total energy of this region is equivalent to 210697222.3 kW/h (210.7 GWh) or 18116.7 toe and represent signifcant energy saving potential. The results indicate the possibility of direct use of energy from TM spring and replacement of fossil fuels, which reduces CO 2 emissions and positively afects the quality of the environment. The use of geothermal energy will reduce heating costs and ensure electricity supply due to the growing need for it. 1. Introduction The challenge of fostering sustainable development cannot be met without the fundamental transformation of global energy systems. Climate change has brought new reasons to challenge the energy policy in order for the environment to be sustained. When sector distribution of GHG emission is taken into consideration, energy sector has the biggest share (82%) [1]. Fossil fuel-fred electric power plants are the largest sources of greenhouse gas emissions [2]. European Union (EU), within its energy policy, used the 2010/31 Directive to present the following goals for the reduction of greenhouse gas emissions: a 30% reduction of greenhouse gas emissions in developed countries by 2020, a 20% improvement of energy efciency by 2020, a 20% increase in share of energy from renewable sources by 2020 [3–6]. The power generation from renewable energy resources has become increasingly important in the world [1]. Political, economic and environmental reasons, as well as the growing need for a more intensive use of existing energy resources, require that Serbia develops new energy sources and achieve energy efciency. The legal framework in Serbia aims to follow EU directives on renewable energy sources and the Kyoto Protocol. The Kyoto and EU directives in many ways contribute to the renewable energy development in the Balkans [7]. Even though the wider use of renewable energy sources is promoted by national, integral and sectoral strategies and planning documents, surprisingly few geographical re- search papers focus on purely energy issues, given the strong link be- tween geographic science and energy. Due to the global increase in the number of inhabitants and the rise in standard of living, there is a growing demand for electricity. For a number of years now, Serbia has an energy defcit, which is growing [8]. With an increase in fossil fuel energy consumption, conventional energy reserves are minimized and conditions and environmental quality worsened. In order to reduce CO 2 emissions and protect the environment, the use of renewable energy sources needs to be increased in relation to fossil fuel energy. Thermal- mineral (TM) springs can be signifcant renewable energy sources, https://doi.org/10.1016/j.rser.2018.12.005 Received 27 July 2018; Received in revised form 3 December 2018; Accepted 4 December 2018 Abbreviations: TM, thermal-mineral; EU, European Union; toe, tonne of equivalent oil ⁎ Corresponding author. E-mail address: dusan.ristic@pr.ac.rs (D. Ristić). Renewable and Sustainable Energy Reviews 102 (2019) 129–138 Available online 13 December 2018 1364-0321/ © 2018 Elsevier Ltd. All rights reserved. T