Geothermal boom in Turkey: Growth in identified capacities and potentials E.D. Korkmaz * , U. Serpen, A. Satman Istanbul Technical University, Faculty of Mines, Department of Petroleum and Natural Gas Engineering, Ayazaga Campus, 34469 Maslak-Istanbul, Turkey article info Article history: Received 6 June 2013 Accepted 30 January 2014 Available online Keywords: Turkey Geothermal energy Resource assessment Hydrothermal potential Capacity abstract Increasing activities of geothermal development especially in the last three years result in a geothermal boom in Turkey. Not only the addition of new sites, but also updating the data of existing ones increased the currently identified capacity significantly. With the discoveries of 13 new geothermal fields, power potentials increased by 1.6 times. This study deals with hydrothermal and EGS potentials of Turkey. The geothermal resource base be- tween 0 and 3 km depth in Turkey and the capacity of the currently identified 290 geothermal sites are determined to be 3.96  10 23 J and 10,576 MW t , respectively. As of today, a total of 135 hydrothermal fields were individually studied, of which 38 medium to high temperature (T  100  C) fields were simulated to estimate the power generation. The remaining 97 fields were simulated to estimate the direct use potentials. The lower and upper limits of power gen- eration potential corresponding to P10 and P90 values are 1673 and 3140MW e , respectively. Moreover, the lower and upper thermal potential limits of 135 hydrothermal fields corresponding to P10 and P90 values are 38.2 and 68.4 GW t , respectively. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction As a developing country, energy and electricity demands in Turkey grow at rates of about 4.5% and 7% per year, respectively. Nearly 75% of energy demand is satisfied with the imported fuels. Therefore, energy dependency on imported resources has become an important issue and of concern. As of 2012, the present installed electricity generating capacity and energy consumption of Turkey have reached to 57 GW e and 119 million TOE (tons oil equivalent), respectively. Official statistics (Ministry of Energy and Natural Re- sources) show that natural gas, coal-liquid fossil fuels, hydro, and other renewables provide 45%, 30%, 23% and 2% of the total elec- tricity of the country, respectively. In order to reduce dependence on imported energy the country needs energy diversification. This diversification could be obtained by adding renewable resources to energy supply portfolio. Although Turkey is rich in renewable energy resource potential such as wind, geothermal and solar, these resources are not yet harnessed sufficiently in terms of energy production. Geothermal energy remains as a small contributor to the power generation capacity of Turkey. Geothermal plants constitute only 0.3% of the installed power generation capacity and provide around 0.5% of total electricity. Although they provide a relatively modest contri- bution, Turkey needs to include geothermal resources in its energy supply portfolio. The assessment and determination of this contribution in a scientific manner are the aim of this study. The first systematic study to assess the geothermal resources was presented by US Geological Survey (USGS) Circular 726 [1]. This assessment was updated in 1978 by USGS Circular 790 [2]. The same year Muffler and Cataldi [3] published their well known paper defining “methods for regional assessment of geothermal re- sources”. This paper presented a simple analytical method for determining resource potential. On the other hand, resource esti- mation reported in USGS Circular 790 by Brook et al. [4] was based on stochastic evaluation method. Later, another stochastic evalua- tion of reserve estimation for low temperature geothermal re- sources was published in USGS Circular 892 by Reed [5]. Muffler and Cataldi [3] mentioned a continuing need to revise geothermal resource assessments, owing to the rapidly changing state of geothermal knowledge, increasing data base, improving * Corresponding author. Tel.: þ90 212 285 60 90; fax: þ90 212 285 62 63. E-mail address: korkmazem@itu.edu.tr (E.D. Korkmaz). Contents lists available at ScienceDirect Renewable Energy journal homepage: www.elsevier.com/locate/renene http://dx.doi.org/10.1016/j.renene.2014.01.044 0960-1481/Ó 2014 Elsevier Ltd. All rights reserved. Renewable Energy 68 (2014) 314e325