Geothermal energy potential for power generation in Turkey: A case study in Simav,Kutahya

Geothermal energy and the other renewable energy sources are becoming attractive solutions for clean and sustainable energy needs of Turkey. Geothermal energy is being used for electricity production and it has direct usage in Turkey, which is among the first five countries in the world for the geothermal direct usage applications. Although, Turkey is the second country to have the highest geothermal energy potential in Europe, the electricity production from geothermal energy is quite low. The main purpose of this study is to investigate the status of the geothermal energy for the electricity generation in Turkey. Currently, there is one geothermal power plant with an installed capacity of 20.4 MWe already operating in the Denizli–Kizildere geothermal field and another is under the construction in the Aydin–Germencik field.This study examines the potential and utilization of the existing geothermal energy resources in Kutahya–Simav region. The temperature of the geothermal fluid in the Simav–Eynal field is too high for the district heating system. Therefore, the possibility of electrical energy generation by a binary-cycle has been researched and the preliminary feasibility studies have been conducted in the field. For the environmental reasons, the working fluid used in this binary power plant has been chosen as HCFC-124. It has been concluded that the Kutahya–Simav geothermal power plant has the potential to produce an installed capacity of 2.9 MWe energy, and a minimum of 17,020 MWh/year electrical energy can be produced from this plant. As a conclusion, the pre-feasibility study indicates that the project is economically feasible and applicable.     

Geothermal resources in Iran: The sustainable future

Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Iran has geothermal energy potential. The Iranian government is considerable attention to the utilization of renewable energy, especially wind, solar and geothermal energies. Due to recent advancements in geothermal energy, many investors in the country have become interested in investing in this type of energy. Geothermal studies in Iran started in 1975 with a cooperative between the ministry of Energy of Iran and ENEL Company from Italy. Preliminary studies indicated potential for geothermal power generation in four areas in northern Iran (Khoy-Maku, Sabalan, Sahand and Damavand at Azarbaijan Gharbi, Ardebil, Azarbaijan Sharghi and Tehran provinces), respectively. Geothermal development in Iran has gained momentum in the last five years with increased exploration and industry growth in the country. Iran is developing a geothermal plant for power production. Iran government plans to build 2000 MW of renewable energy capacity over the next five years. Total projected use (geothermal capacity) has been estimated 100 MW at the end of 2010. Exploration drilling is currently in-progress for Meshkinshahr project in North-Western Iran. The Sabalan geothermal power plant is expected to produce 50 MW electric powers in 2011. The plants are planned by Iran Ministry of Energy and the Renewable Energy Organization of Iran (SUNA). This study presents a brief introduction to the resource, status and prospect of geothermal energy in Iran.     

A snapshot of geothermal energy potential and utilization in Turkey

Turkey is one of the countries with significant potential in geothermal energy. It is estimated that if Turkey utilizes all of her geothermal potential, she can meet 14% of her total energy need (heat and electricity) from geothermal sources. Therefore, today geothermal energy is an attractive option in Turkey to replace fossil fuels. Besides, increase in negative effects of fossil fuels on the environment has forced many countries, including Turkey, to use renewable energy sources. Also, Turkey is an energy importing country; more than two-thirds of her energy requirement is supplied by imports. In this context, geothermal energy appears to be one of the most efficient and effective solutions for sustainable energy development and environmental pollution prevention in Turkey. Since geothermal energy will be used more and more in the future, its current potential, usage, and assessment in Turkey is the focus of the present study. The paper not only presents a review of the potential and utilization of the geothermal energy in Turkey but also provides some guidelines for policy makers.     

Geothermal energy utilization trends from a technological paradigm perspective

The use of geothermal energy and its associated technologies has been increasing worldwide. However, there has been little paradigmatic research conducted in this area. This paper proposes a systematic methodology to research the development trends for the sustainable development of geothermal energy. A novel data analysis system was created to research the geothermal energy utilization trends, and a technological paradigm theory was adopted to explain the technological changes. A diffusion velocity model was used to simulate and forecast the geothermal power generation development in the diffusion phase. Simulation results showed that the development of installed capacity for geothermal generation had a strong inertia force along with the S-curve. Power generation from geothermal power sources reached a peak in 2008 and is estimated to be saturated by 2030. Geothermal energy technologies in hybrid power systems based on other renewable energy sources look to be more promising in the future.     

Importance of geothermal energy and its environmental effects in Turkey

Geothermal energy, a relatively benign energy source when compared with other energy sources due to reduction in greenhouse gas emissions, is used for electricity generation and direct utilization. Turkey has a place among the first seven countries in the world in the abundance of geothermal resources, but it has only used about 4% of its potential. The paper presents the status of energy needs and renewables, potential, utilization and the importance of geothermal energy in Turkey. It also gives a comparison between geothermal energy and other energy sources regarding environmental issues. It is estimated that if the geothermal heating potential alone in Turkey is used, 5 million residences will be heated and as a result, releases of 48 million ton/year CO₂ emissions into the atmosphere will be prevented. In addition to this, if the other geothermal potential (i.e. electricity) is used it will provide considerable environmental benefits. Therefore, it is expected that geothermal energy development will significantly speed up in the future.     

An alternative pathway from hot dry rock to green hydrogen by organic Rankine cycle applications

Some researchers have been focused on electricity generation using thermal energy extraction from HDRs via Organic Rankine cycles. This new research topic creates a new pathway to reach green hydrogen for countries that have geothermal power such as Turkey. In this study, a well in the Nevşehir region that does not has the potential to be used in direct geothermal energy applications due to the absence of water was examined. By using the heat obtained from HDR by injected water, the estimated amount of electricity that can be produced with a single shaft binary organic Rankine cycle was revealed by calculating the thermal energy that can be obtained from the wells which have a surface temperature of 183 °C at 2900 m 2900 m depth. In the next step, the hydrolysis of water with electricity obtained from renewable energy and the hydrogen potential that can be produced were revealed. This hydrogen, which is estimated to be produced, can be fed directly to the natural gas lines or subjected to processes such as storage or industrial usage.     

Efficiency improvement for geothermal power generation to meet summer peak demand

Geothermal power is an important part of New Zealand's renewable electricity supply due to its attractive cost and reliability. Modular type binary cycle plants have been imported and installed in various geothermal fields in New Zealand, with plans for further expansion. Power output of these plants deteriorates in the summer because plant efficiency depends directly on the geothermal resource and the ambient temperature. As these plants normally use air-cooled condensers, incorporating a water-augmented air-cooled system could improve the power output in summer thereby matching the peak air-conditioning demand. In this work, power generation for the Rotokawa plant was characterized using a similar plant performance and local weather. The improved performance was modelled for retrofit with a wet-cooling system. Maximum generation increase on the hottest day could be 6.8%. The average gain in power over the summer, November–February, was 1.5%, and the average gain for the whole year was 1%. With current binary unit generation capacity at the Rotokawa plant of 35 MW, investment in a water-augmented air-cooled system could provide 2 MW of peak generation on the hottest days. This investment in efficiency is found to compare favourably to other supply options such as solar PV, wind or gas.     

Power generation from geothermal resources in Turkey

This study provides information on power generation via geothermal resources and sector development. The first instance of power generation from geothermal resources was performed by a state-owned power plant at Kızıldere-Denizli, whereas the first private sector investment was the Dora-I power plant, commissioned in 2006. Legislation regulating rights ownership and certification laws was issued in 2007. The installed capacity of the geothermal resources is 311.871 MW for 16 power plants, and power generation licenses were issued for 713.541 MW at the end of 2012. The total potential geothermal power that can be generated in Turkey is estimated to be approximately 2000 MW. The geothermal fields in Turkey produce high levels of greenhouse gases, which have been deemed highly responsible for global warming. Due to high CO₂ emissions, the geothermal energy sector risks a carbon tax in the near future. For certain geothermal resources, multiple investors produce electricity from the same resource. The sector will inevitably experience severe damage unless permanent solutions are devised for problems related to sustainably managing geothermal resources and environmental problems.     

Turkey's Renewable Energy Facilities in the Near Future

In this work, renewable energy facilities of Turkey were investigated. Electricity is mainly produced by thermal power plants, consuming coal, lignite, natural gas, fuel oil and geothermal energy, and hydro power plants in Turkey. Turkey has no large oil and gas reserves. The main indigenous energy resources are lignite, hydro and biomass. Turkey has to adopt new, long-term energy strategies to reduce the share of fossil fuels in primary energy consumption. For these reasons, the development and use of renewable energy sources and technologies are increasingly becoming vital for sustainable economic development of Turkey. The most significant developments in renewable production are observed hydropower and geothermal energy production. Renewable electricity facilities mainly include electricity from biomass, hydropower, geothermal, and wind and solar energy sources. Biomass cogeneration is a promising method for production bioelectricity.     

Geothermal energy in Turkey: the sustainable future

Turkey is an energy importing nation with more than half of our energy requirements met by imported fuels. Air pollution is becoming a significant environmental concern in the country. In this regard, geothermal energy and other renewable energy sources are becoming attractive solution for clean and sustainable energy future for Turkey. Turkey is the seventh richest country in the world in geothermal energy potential. The main uses of geothermal energy are space heating and domestic hot water supply, greenhouse heating, industrial processes, heat pumps and electricity generation. The district heating system applications started with large-scale, city-based geothermal district heating systems in Turkey, whereas the geothermal district heating centre and distribution networks have been designed according to the geothermal district heating system (GDHS) parameters. This constitutes an important advantage of GDHS investments in the country in terms of the technical and economical aspects. In Turkey, approximately 61,000 residences are currently heated by geothermal fluids. A total of 665 MW_t is utilized for space heating of residential, public and private property, and 565,000 m² of greenhouses. The proven geothermal heat capacity, according to data from existing geothermal wells and natural discharges, is 3132 MWt. Present applications have shown that geothermal energy is clean and much cheaper compared to the other fossil and renewable energy sources for Turkey.     

Ranking locations for producing hydrogen using geothermal energy in Afghanistan

Geothermal energy is a type of renewable energy with high availability and independence from climatic and atmospheric conditions. It has been shown that geothermal energy is technically, economically and environmentally more suitable for hydrogen production than other renewable sources. Hydrogen has wide applications in many fields including cooling, oil, gas, petrochemical, nuclear, and energy industries. Afghanistan has significant potential in geothermal power generation and also several hydrogen-consuming industries that provide opportunities for geothermal-based hydrogen production. This study attempted to find suitable locations for the construction of geothermal power plant for hydrogen production in Afghanistan. Given the multitude of criteria involved in the choice of location, evaluations and comparisons were performed using multi-criteria decision-making methods. Nine criteria were used to evaluate 17 Afghanistan provinces in terms of suitability for geothermal-based hydrogen production. The SWARA (Stepwise Weight Assessment Ratio Analysis) method was used to weight the criteria and then the ARAS (Additive Ratio Assessment) method was used to rank the provinces. The results were validated. The results showed that Sari pul, Balkh and Herat are the most suitable Afghanistan provinces and Zabul, Ghor and Kandahar are the least suitable Afghanistan provinces for geothermal-based hydrogen production. The three methods produced almost identical rankings with only minor differences in the overall ranking of some provinces.     

Classification of geothermal resources in Poland by exergy analysis—Comparative study

Geothermal resources in Poland are of growing importance for the production of renewable energy. The total installed geothermal capacity (including heat pumps) at the end of 2008 was ca. 281 MW_t, while heat sales about 1501 TJ. Poland is characterised by low-temperature geothermal resources connected mostly with the Mesozoic sedimentary formations. In the paper the estimation of thermodynamic potential of Polish geothermal fields in comparison with selected global resources was presented. Geothermal resources were classified with reference to their specific exergy and specific exergy index (SEI). These indices define the quality of the energy content of a geothermal fluid better than conventional temperature criterions.     

Evaluation of a new geothermal based multigenerational plant with primary outputs of hydrogen and ammonia

Increasing environmental concerns and decreasing fossil fuel sources compel engineers and scientists to find resilient, clean, and inexpensive alternative energy options Recently, the usage of renewable power resources has risen, while the efficiency improvement studies have continued. To improve the efficiency of the plants, it is of great significance to recover and use the waste heat to generate other useful products. In this paper, a novel integrated energy plant utilizing a geothermal resource to produce hydrogen, ammonia, power, fresh water, hot water, heated air for drying, heating, and cooling is designed. Hydrogen, as an energy carrier, has become an attractive choice for energy systems in recent years due to its features like high energy content, clean, bountiful supply, non-toxic and high efficiency. Furthermore in this study, hydrogen beside electricity is selected to produce and stored in a hydrogen storage tank, and some amount of hydrogen is mixed with nitrogen to compound ammonia. In order to determine the irreversibilities occurring within the system and plant performance, energy and exergy analyses are then performed accordingly. In the design of the plant, each sub-system is integrated in a sensible manner, and the streams connecting sub-systems are enumerated. Then thermodynamic balance equations, in terms of mass, energy, entropy and exergy, are introduced for each unit of the plant. Based on the system inputs and outputs, the energy and exergy efficiencies of the entire integrated plant is found to be 58.68% and 54.73% with the base parameters. The second part of the analysis contains some parametric studies to reveal how some system parameters, which are the reference temperature, geothermal resource temperature and mass flow rate, and separator inlet pressure in the geothermal cycle, affect both energy and exergy efficiencies and hence the useful outputs.     

Geothermal power production in future electricity markets—A scenario analysis for Germany

Development and diffusion of new renewable energy technologies play a central role in mitigating climate change. In this context, small-scale deep geothermal power has seen growing interest in recent years as an environmentally friendly, non-intermittent energy source with large technical potential. Following the first successful demonstration projects, the German geothermal industry is currently experiencing an internationally unparalleled growth. In this study we explore the factors driving this development, and the role geothermal power production could play in the future of the German electricity market. For this, we apply the scenario technique, based on literature analysis and interviews with companies operating actively in the field. Our findings highlight the importance of political support and framework conditions in the electricity market, with the best prospects in a decentralised energy system based on renewable energy sources, where high investment costs and the risk of discovery failure are balanced by the benefits of low-carbon base load power.     

Hydropower for sustainable water and energy development

Turkey has a total gross hydropower potential of 433 GWh/year, but only 125 GWh/year of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 36% of the economically usable potential of the country would be tapped. Turkey presently has considerable renewable energy sources. The most important renewable sources are hydropower, biomass, geothermal, solar and wind. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. Over the last two decades, global electricity production has more than doubled and electricity demand is rising rapidly around the world as economic development spreads to emerging economies. Not only has electricity demand increased significantly, it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries.     

Present status and potential role of geothermal energy in the world

Geothermal energy has come of age as an energy source. It is found in most parts of the world and is harnessed by conventional technology. Commercial production on the scale of hundreds of MW has been undertaken for over three decades both for electricity generation and direct utilization. Some 80 countries have identified geothermal resources, and about 50 have quantifiable geothermal utilization at present. Electricity is produced from geothermal in 21 countries (total production 38 TWh/a) and direct application is recorded in 35 countries (34 TWh/a). Geothermal electricity production is equally common in industrialized and developing countries, but plays a more important role in the latter. Apart from China, direct use is mainly in the industrialized countries and Central and Eastern Europe. Most of the developing countries as well as Central and Eastern European countries still lack trained manpower, but there is a surplus in many industrialized countries. During 1973–1992, investments in geothermal energy amounted to approximately 22 billion USD. The large share of the private sector in the investments shows its confidence in this energy source. Data presented in the WEC Survey of Energy Resources 1995 on the “new renewables” (geothermal, solar, wind, and tidal energy) shows that geothermal has the largest installed electrical capacity (61%) and electricity production (81%) in the world of these four sources.     

Hydropower–water and renewable energy in Turkey: Sources and policy

Turkey's energy consumption has been growing much faster than its production. It forces Turkey to make a rapid action to supply energy demand. From the viewpoint of primary energy sources (petroleum and natural gas), Turkey is not a rich country, but it has an abundant hydropower potential to be used for generation of electricity. Hydropower is the most important kind of renewable, sustainable energy and a proven technology for electricity generation. The aim of this paper is to discuss sources and policy of hydropower, water and renewable energy in Turkey and compares the hydropower application with Europe.     

As a renewable energy hydropower for sustainable development in Turkey

The most important renewable sources are hydropower, biomass, geothermal, solar and wind. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. In recently, electricity has demand increased significantly; it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix. In the world, particularly in the developing countries renewable energy resources appear to be one of the most efficient and effective solutions for sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of the renewable energy sources. This paper deals with policies to meet increasing energy and electricity demand for sustainable energy development in Turkey. Turkey has a total gross hydropower potential of 433 GWh/year, but only 125 GWh/year of the total hydroelectric potential of Turkey can be economically used.     

Production engineering in geothermal technology: A review

Geothermal energy is abundant and renewable, but only a very small fraction can currently be converted commercially to electricity and heating value with today's technology. In recent years, the installed geothermal capacity worldwide has more than doubled. The increase in the use of geothermal energy is the result of a multi-disciplinary effort. Highlighted are some production engineering advances that have played a significant part in making geothermal a competitive renewable energy resource.     

Sustainable development of Turkey: Deployment of geothermal resources for carbon capture,utilization, and storage

As a developing country, Turkey’s sustainable development objectives converge on robust and sustainable economic development. The increase in its energy and electricity demand is attributed to the growth of population, urbanization, and industrialization parallel to economic and social growth. Instead of fulfilling the obligation to protect the environment arising from international agreements and achieving desired sustainable development, the dependency on imported fossil fuel in electrical energy production and energy-intensive economic growth results in intensified CO₂ emission as well as ironically negative economic output. Therefore, Turkey is forced to exploit its indigenous sources such as coal (which unfortunately increases atmospheric Green House Gas “GHG” emissions) and renewable resources. However, high GHG emission – mainly CO_{2 –} of Turkey’s coal power plants impairs deployment of indigenous sources for power generation. Indeed, there is a necessity of technical approaches for higher heat extraction efficiencies and mitigation of high concentration of energy-related CO₂ emission. Admittedly, “Carbon Capture, Utilization, and Storage (CCUS)” employing conventional hydrothermal resources offers highly efficient heat extraction, geological CO₂ sequestration, and utilization of CO₂ for power generation rather than considering CO₂ as an effluent. Although there are research gaps and lack of field scale experiment, the economic and environmental viability of implementing CCUS in Turkey can be improved by pilot or field scale projects whereby the presence of these projects commences technological and experimental advances in capturing CO₂ either from geothermal power plants or indigenous coal power plants, transporting it to the proven geothermal geologic site, and generating power. Apart from this, the “CO_{2 –} Plume Geothermal Systems (CPG)” compared to unconventional and conventional geothermal systems would commit vigorous potential for continual improvement in economic feasibility of CCUS without a guaranteed return on power generation investments in Turkey. Hence, legislations concerning incentives in CCUS would foster further improvements in the deployment of geothermal resources to pursue sustainable development in Turkey.