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Energy storage is one of the key technologies for energy conservation and therefore is of great practical importance. One of its main advantages is that it is best suited for solar thermal applications. This study deals with a comprehensive discussion of the evaluation and the selection of sensible and latent heat storage technologies, systems and applications in the field of solar energy. Several issues relating to energy storage are examined from the current perspective. In addition, some criteria, techniques, recommendations, checklists on the selection, implementation and operation of energy storage systems are provided for the use of energy engineers, scientists and policy makers. Copyright © 1999 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary: Human activities are directly related to fossil fuel consumption and cause global warming and climate change effects by emitting greenhouse gas into the lower atmosphere. To reduce and adapt to such effects, renewable energy sources such as surface dams, including hydroelectric energy (HE) generation units, are gaining importance. In the current literature, HE potential calculations are based on formulations that are quite simple, clear and do not distinguish between different situations. In this paper, two classification methodologies are proposed for better assessment of HE production. The first one is based on the concept of the hypsographic curve to distinguish different drainage basin features into "Young," "Mature" and "Old." The second classification takes into account the newly defined energy index (EI) principle, which helps to classify the HE generation capability of drainage basins into "Very low," "Low," "Normal," "High" and "Very high." The application of the proposed methodology is presented for three drainage basins from the upstream sub‐basins of the Tigris River in Turkey. A comparison of the results shows that the proposed methodologies not only give numerical values but also sets linguistically rational and logical rules for the HE potential of a drainage basin. In the upstream basin of the Tigris River, the EI values vary between 0.705 and 0.122, corresponding to the "High" and "Low" categories, respectively. It is recommended that these two classification procedures be considered before the construction of any dam for HE production. [ABSTRACT FROM AUTHOR]

Summary: Today, it has become imperative to design these systems at optimum size to make reliable and minimize the total costs of renewable energy systems. There are many studies about size optimization in the literature. However, few studies have approached the problem with a heuristic method at different levels of reliability and compared the results with commercial software. This paper aims to fill this gap by proposing an artificial bee colony (ABC) algorithm with different reliability ratios for renewable energy systems size optimization and comparing the results of the proposed method with the results of the HOMER Pro software. The current methodology is validated with a real case study on the load demand of a school building (latitude 41.37, longitude 27.3) in Turkey. The peak and average load per day for the school building are 7.4 kW and 51.8 kW, respectively. The proposed method has presented 14.71%, 14.36%, and 6.23%, respectively, more economical solutions than HOMER Pro software for hybrid photovoltaic (PV)/wind/battery, PV/battery, and wind/battery renewable energy system scenarios. In addition, the ABC algorithms with different reliability ratios (%0, %0.2, %1, and %3) are used to analyze the effect on the system cost of the loss of power supply probability. According to the results, the hybrid renewable energy system consisting of 230 PV panels, 6 wind turbines, and 34 batteries is the most economical option with a total annual cost of $42 717.58 compared to stand‐alone systems with a reliability %0 ratio. It has been seen that increasing the loss of power supply probability reduces system costs. Consequently, this study shows that using the ABC algorithm in size optimization of renewable energy systems yields accelerates the decision‐making process and more optimized solutions. [ABSTRACT FROM AUTHOR]

Summary: The application of renewable energy sources in electrical energy generation is becoming widespread due to the decrease of installation costs and the increase of environmental concerns. Hybrid power generation systems are advantageous to meet the load demand, but optimal sizing is the main concern for having a cost‐effective system based on given load demand and techno‐economic indicators. This paper proposes a deterministic algorithm and utilizes genetic and artificial bee colony (ABC) optimization algorithms for optimal sizing of PV/battery and PV/WT/battery hybrid systems with minimum levelized cost of electricity (LCOE) constraint for two locations, Nigde and Bozcaada, in Turkey. The loss of power supply probability (LPSP) is used to build a reliable system and to make sure that the system produces required energy. Experimental results showed that optimal sizing of each location is different due to different wind and solar characteristics of locations. PV/battery model is more suitable for Nigde location with 1.22% LPSP and 0.1514 [$/kWh] LCOE, while PV/WT/battery model is more cost‐efficient for Bozcaada location with 1.952% LPSP and 0.0872 [$/kWh] LCOE. Time performances of the algorithms are also investigated. It has been seen that the ABC algorithm has better performance and less execution time. This study demonstrated that heuristic algorithms are more applicable than deterministic algorithms, due to fast discovery of optimal solutions for hybrid renewable energy systems. [ABSTRACT FROM AUTHOR]

Summary Wind energy, with its high potential, has an important place among renewable energy sources. Therefore, the number of investments on wind energy is increasing with new turbine technologies and solutions. For the investors of these technologies, how to determine the location of wind turbines for such investments is a challenging and critical problem. Wind maps of the country are a useful resource to determine high potential locations. However, such maps often present an overview to provide the general picture, and there is a need for a more detailed analysis, specifically on the potential plant area. In this paper, we investigate the use of a recent regional wind power forecast method to determine the wind power potential. By applying the RegionalSHWIP on a potential plant area, investors can obtain the preliminary power prediction, hence the wind potential of the area, without any financial cost recurring for measurements and with negligible manhour for computation. The wind resource assessments of the RegionalSHWIP have been analyzed in comparison to the wind maps of four provinces from different regions of Turkey. In all of these test provinces, it has been observed that the model produces results compatible with the values in the wind potential atlas. In addition, the proposed model has been run on 16 online power plants by selecting 4 different real wind power plants from each province, pretending that these power plants are offline. It has been observed that the total MWh values obtained from the actual generation of these power plants and the total MWh values obtained by estimation are also compatible and the results have been found to support the model. [ABSTRACT FROM AUTHOR]

Often, solar irradiation estimation from simply measureable sunshine duration data is achieved by linear and nonlinear regression expressions, which depicts the statistical regression equation between the sunshine duration and solar irradiation data. These models are based on statistical parameters only, and therefore, the estimations do not take into consideration deviations from the averages. In this paper, an innovative probability methodology is proposed for solar irradiation estimation, which is based on the cumulative probability distribution functions (CDFs) of the sunshine duration and solar irradiation data. For this purpose, the sunshine duration data are converted to match the solar irradiation data cumulative distribution (CDF), which is then employed for the solar irradiation estimation. Hence, the CDFs of sunshine duration and solar irradiation data are preserved, and rather than global average, pointwise solar irradiation estimations are achieved. The application of the innovative probabilistic methodology is presented for seven solar irradiation measurements stations from different climate regions in Turkey. It is shown that the suggested method over performs other methodologies with very high improvements. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Predictions of wind energy potential in a given region are based on on-location observations. The time series of these observations would later be analysed and modelled either by a probability density function (pdf) such as a Weibull curve to represent the data or recently by soft computing techniques, such as neural networks (NNs). In this paper, discrete Hilbert transform has been applied to characterize the wind sample data measured on İzmir Institute of Technology campus area which is located in Urla, İzmir, Turkey, in March 2001 and 2002. By applying discrete Hilbert transform filter, the instantaneous amplitude, phase and frequency are found, and characterization of wind speed is accomplished. Authors have also tried to estimate the hourly wind data using daily sequence by Hilbert transform technique. Results are varying. [ABSTRACT FROM AUTHOR]

SUMMARY The Turkish wind energy industry is one of the most competitive and fastest growing industries in the energy sector. Industrial energy demands, Kyoto agreement and carbon trade are shown as probable causes. Currently, Turkey has a total installed capacity of about 48.5 GW for electricity from all energy sources. High energy prices and unstable suppliers have stimulated Turkey's growing interest in wind business and wind power. This paper analyzes Turkey's wind energy future perspective and power generation strategy with a view to explaining Delphi approach to wind energy development. In this study, the two-round Delphi survey was conducted by experts to determine and measure the expectations of the sector representatives through online surveys where a total of 70 experts responded from 24 different locations. The majority of the Delphi survey respondents were from 23 different universities (60%), electricity generation industries (21%), two different governmental organizations (11%), nongovernmental organizations (6%) and other institutions (2%). The article discusses not only the expert sights on wind energy technology but also all bibliometrical approaches. The results showed that Turkey's wind power installed capacity is expected to exceed 40 GW by the end of the 2020 s and in the middle of the 2030 s, and Turkey would be the European leading country in the field of electricity generation from the wind. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Turkey is rich in both geothermal energy and lignite reserves, which in many cases, are co-located. This condition makes it feasible to utilize both lignite and geothermal energy in a hybrid form for combined power heat, and cold generation, which may lead to optimally energy and exergy efficient, environmentally benign, and economically sound applications. This paper presents a novel concept of hybrid lignite-geothermal plant for a district energy system and hydrogen production facility in Aydin with special emphasis on high performance, green buildings and green districts. In this concept, lignite is first introduced to a partially fluidized-bed gasifier and then to a fluidized-bed gas cleaning unit, which produces synthetic gas and finally Hydrogen. The by-products, namely char and ash are used in a fluidized-bed combustor to produce power. Waste heat from all these steps are utilized in a district heating system along with heat received from geothermal production wells after power is generated there. HS gas obtained from the separator system is coupled with hydrogen production process at the lignite plant. Absorption cooling systems and thermal storage tanks complement the hybrid system for the tri-generation district energy system. On the demand side, the new, green OSTIM OSB administration building in Ankara is exemplified for greener, low-exergy buildings that will compound the environmental benefits. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

For optimum design of borehole thermal energy storage (BTES) and ground sources heat pump (GSHP) applications, determination of underground thermal properties is required. The design and economic feasibility (number and depth of boreholes) of these systems need thermal conductivity of geological structure, λ (W m-1 K-1), and thermal resistance of ground heat exchanger, R (K W-1 m). Thermal properties measured in laboratory experiments do not coincide with data of in situ conditions. Therefore, in situ thermal response test equipment has been developed and used in Canada, England, Germany, Norway, U.K., U.S.A. and Sweden to ensure precise designing of BTES systems. This paper describes the results and evaluations of the Adana continual thermal response test measurements. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, the effect of various system parameters on horizontal ground source compression refrigeration machine (CRM) performance is studied experimentally in Bursa, Turkey. A ground heat exchanger (GHE) system connected to CRM in a test room in the air conditioning and refrigeration laboratory of Uludag University has been designed and constructed. This system was tested for space cooling in August and September 2004 and performance tests were performed during this period. Overall, system mainly consists of the GHE (GHE–water circuit) and CRM (CRM–refrigerant circuit). Refrigerant is R134a. Hourly variations of inlet and outlet water temperatures, extracted heat from test room, rejected heat to ground, compression ratio, total power consumption, and coefficient of performance (COP) values for both whole system and only CRM are obtained. Thermal properties of soil are also estimated by using experimental data and theory. Cooling load of test room and rejected heat to ground, and all COP values are also presented. Finally, heat rejection rate to ground with respect to leaving water temperature from GHE is given. The COP of the overall system changes between 2 and 2.5, also CRM COP values are in the range of 3 and 3.86. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, an adaptive simulated annealing genetic algorithm is proposed to solve generation expansion planning of Turkey's power system. Least-cost planning is a challenging optimization problem due to its large-scale, long-term, nonlinear, and discrete nature of power generation unit size. Genetic algorithms have been successfully applied during the past decade, but they show some limitations in large-scale problems. In this study, simulated annealing is used instead of mutation operator to improve the genetic algorithm. The improved algorithm is applied to the power generation system with seven types of generating units and a 20-year planning horizon. The planning horizon is divided into four equal periods. The new algorithm provides approximately 6.6 billion US$ (3.2%) cheaper solution than GA and also shows faster convergence. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary: Estimation of solar radiation (SR) carries importance for planning available renewable energy, and it is also beneficial for solving agricultural, meteorological, and engineering problems. This study compares the ability of hybrid adaptive neuro fuzzy (ANFIS) models and long short‐term memory to search a suitable approach for SR prediction with minimum number of input parameters (temperature) in Mediterranean region of Turkey, which could be useful for the regions in which other effective parameters (eg, relative humidity, wind speed) are not available. The models considered were assessed by considering four data splitting scenarios, 50% train—50% test, 60% train—40% test, 70% train—30% test, and 80% train—20% test. Among the hybrid methods, the ANFIS with grey wolf optimization and genetic algorithm showed a superior accuracy. The study shows that applying different data splitting scenarios is necessary for better assessment of the data‐driven methods since the accuracies of the implemented methods increase by about 30% to 60% when the splitting data scenario varies from 50‐50% to 80‐20%. Sensitivity analysis shows that the performance of the model increases by about 40% using extraterrestrial radiation for the best model. The ANFIS with grey wolf optimization and genetic algorithm is recommended to predict monthly solar radiation with limited input data. [ABSTRACT FROM AUTHOR]

Summary: Equipping highways with charging stations (CSs) is a fundamental step for travelling with electric vehicles (EVs) between cities and countries conveniently. This article focuses on locating CSs to fully connect roads that may require multiple charging events by considering the minimum driving range for all possible paths in a transportation network. For this purpose, we present a new binary integer linear programming model named the Range Coverage Location Model (RCLM) to find the minimum required CSs and their locations that the driving range can cover without defining the paths in the network. By adding the result of RCLM as a constraint to the model, the optimum locations that maximize the EV flows are determined with the RCLM‐Max model. Two versions of the RCLM are introduced. The link‐based RCLM is designed for problems in which there are CSs in each of the origin/destination (OD) nodes (intersections), while the network‐based RCLM aims to connect links without stopping by the OD nodes, making the model stricter but convenient for EV travels. The proposed models are validated through extensive computational experiments with real data from a highway network in Turkey. The experiments show that RCLM and RCLM‐Max can solve very large‐scale problems in a very short CPU time. The findings suggest that the link‐based RCLM can be applied when the budget is at the forefront, and the network‐based model is preferred if the aim is to connect the main roads without stopping by the OD nodes. [ABSTRACT FROM AUTHOR]

Summary: Generally, wind energy production is based on the average wind speed without any classification. This article proposes a classification system on the basis of wind speed durations greater than a given threshold value. For this purpose, the wind quality designation (WQD) concept is defined based on the wind potential duration, amount, and intensity on a threshold level. Its classifications are depicted on five risk percentage classes as "excellent," "very good," "good," "fair," and "weak. Apart from the classification, the change of WQD with wind speed threshold provides qualitative and quantitative wind speed energy production assessment. The specific objective of the article is to present theoretical WQD explanations on the basis of the most frequently employed two‐parameter Weibull probability distribution function (PDF). The application is provided for Adiyaman City, Kahta meteorology station wind speed records from the Southeastern province of Turkey. It is noticed that there is no "Weak" category at this station and the most effective quality class is "Excellent" from 14 m/s to almost 27 m/s wind speeds. The average wind speed corresponds to about 62% WQD. Finally, the wind speed potential durations PDF abides by the logarithmic‐normal PDF, whereas amount and intensity accord with the Weibull PDFs. [ABSTRACT FROM AUTHOR]

This paper investigates the status of geothermal development in Turkey as of the end of 1999. Turkey is one of the countries with significant potential in geothermal energy. Resource assessments have been made many times by the Mineral Research and Exploration Directorate (MTA) of Turkey. The main uses of geothermal energy are mostly moderate- and low-temperature applications such as space heating and domestic hot water supply, greenhouse heating, swimming and balneology, industrial processes, heat pumps and electricity generation. The data accumulated since 1962 show that the estimated geothermal power and direct use potential are about 4500 MWe and 31 500 MWt, respectively. The direct use capacity in thermal applications is in total 640 MWt representing only 2 per cent of its total potential. Since 1990, space heating and greenhouse developments have exhibited a significant progress. The total area of greenhouses heated by geothermal energy reached up to about 31 ha with a heating capacity of 69.61 MWt. A geothermal power plant with a capacity of 20.4 MWe and a CO2 factory with a capacity of 40000 ton yr−1 have been operated in the Denizli-Kizildere field since 1984 and 1986, respectively. Ground source heat pumps have been used in residential buildings for heating and cooling for approximately 2 years. Present applications have shown that geothermal energy in Turkey is clean and much cheaper compared to the other energy sources like fossil fuels and therefore is a promising alternative. As the projects are recognized by the public, the progress will continue. Copyright © 2001 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary: Due to the extraordinary impact of the Coronavirus Disease 2019 (COVID‐19) and the resulting lockdown measures, the demand for energy in business and industry has dropped significantly. This change in demand makes it difficult to manage energy generation, especially electricity production and delivery. Thus, reliable models are needed to continue safe, secure, and reliable power. An accurate forecast of electricity demand is essential for making a reliable decision in strategic planning and investments in the future. This study presents the extensive effects of COVID‐19 on the electricity sector and aims to predict electricity demand accurately during the lockdown period in Turkey. For this purpose, well‐known machine learning algorithms such as Gaussian process regression (GPR), sequential minimal optimization regression (SMOReg), correlated Nyström views (XNV), linear regression (LR), reduced error pruning tree (REPTree), and M5P model tree (M5P) were used. The SMOReg algorithm performed best with the lowest mean absolute percentage error (3.6851%), mean absolute error (21.9590), root mean square error (29.7358), and root relative squared error (36.5556%) values in the test dataset. This study can help policy‐makers develop appropriate policies to control the harms of not only the current pandemic crisis but also an unforeseeable crisis. [ABSTRACT FROM AUTHOR]

Summary: The usage of stand‐alone power systems represents an excellent choice for remote communities that are impossible to couple to the electricity distribution network practicably. The current research aims to design a no grid tied hybrid system on the basis of a PV‐wind turbine‐hydrokinetic turbine and diesel generator, for the purpose of meeting the electricity needs of a house near the Seyhan River, Turkey. A software that performs hybrid optimization of systems that can generate energy using different energy sources was utilized for modeling the operation of systems and identifying the appropriate architecture. In the current research, simulations were carried out for eight different (off‐grid) power systems. The best optimized off‐grid hybrid power system comprises a photovoltaic array of 7.87 kW, two wind turbines, one hydrokinetic turbine, a diesel generator of 7 kW, lead‐acid batteries of 49 kWh, and a converter of 4.95 kW. The results of the present research demonstrated that the total net present cost was $161 327.08, while the levelized cost of electricity was $0.609/kWh for the optimized system. Furthermore, the renewable usage fraction and carbon dioxide emissions are 26.4% and 838.63 kg/year, respectively. In accordance with the simulation findings, the wind‐hydrokinetic power system has higher levelized cost of electricity and total net present cost in comparison with other power generation systems. [ABSTRACT FROM AUTHOR]

Summary: Despite the impact of personnel scheduling on the sustainability of production processes, it is a rarely studied problem in the electricity generation sector, whose main purpose is sustainable energy generation. From this point of view, personnel scheduling problem is handled in this study based on the impact of this problem, which focuses on fair and balanced job distribution according to the personnel qualifications, on the sustainable generation in the power plants. With its advantages such as ease of operation and maintenance, fast commissioning, lower greenhouse gas emissions compared to other fossil fuels and etc. one of the biggest Natural Gas Combined Cycle Power Plant (NGCCPP) in Turkey is chosen as application area. The main purpose of the study is to demonstrate the effect of fair, balanced and competency‐based personnel scheduling on generation stoppages resulting from personnel planning in power plants, which have great importance in energy supply security of the countries. This study is the first in the literature in terms of three different aspects. Firstly, in the energy sector, it is different in that it is a personnel scheduling study that takes into consideration the job assignment of the personnel according to their abilities and minimizes costs. Secondly, the large size of the problem is different from that of previous studies in the literature. Finally, the number of personnel employed in this generation facility varies according to the season. At this point, the past generation data are analyzed using an Artificial Neural Network (ANN) method and an estimation is made, and personnel scheduling is performed in the light of this information. Consequently, the proposed multi‐objective mathematical model supported with multi‐criteria decision making and ANN, shutdown rate of the power plant due to operator error is reduced 67.3%, and personnel satisfaction level is increased from 42% to 89%as solution. [ABSTRACT FROM AUTHOR]

Summary: Hydrogen can be considered as the most promising fuel towards the greenization. Developed and developing countries around the world have formed their research, investments and directives on hydrogen. The leading countries in this field can be cited as members of the European Union and the United States. Laws and regulations have been shared with the public under the aegis of the established policies. Additionally, determined targets for the short, medium and long term and their feedbacks are recorded by the reports of the competent authorities. Although the Republic of Turkey was aware of the importance of the issue, though there is no open source inventory as disclosed. In Turkey, governmental organization, General Directorate of Energy Affairs (YEGM), and foundations, such as the National Hydrogen Association (NHA), have been encouraging and supporting multidisciplinary studies and activities within the country and internationally. In this study, it is aimed to provide numerical analyses from 1970 to the present by considering hydrogen energy. Related information and data were compiled from online resources on scholarly publications, organizations, groups, books and book chapters, master and doctorate theses, patents received and completed projects. It is also aimed to create a unique information source to refer with respect to planning and activities. [ABSTRACT FROM AUTHOR]

The study deals with the energetic and exergetic analyses of a cogeneration (combined heat and power, CHP) system installed in a ceramic factory, located in Izmir, Turkey. This system has three gas turbines with a total capacity of 13 MW, six spray dryers and two heat exchangers. In the analysis, actual operational data over one-month period are utilized. The so-called CogeNNexT code is written in C++ and developed to analyze energetic and exergetic data from a database. This code is also used to analyze turbines, spray dryers and heat exchangers in this factory. Specifications of some parts of system components have been collected from the factory. Based on the 720 h data pattern (including 43 200 data), the mean energetic and exergetic efficiency values of the cogeneration system are found to be 82.3 and 34.7%, respectively. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In developing countries, energy consumption is continuously increasing in parallel to the developing technology. Turkey is one of these countries with its increasing population and energy demand, which increases every year with a very high rate, that is, 8% annually. Moreover, along with the increasing energy demand, the strategic energy policies have to be analyzed scientifically including the geographical importance for the realization phase. It is necessary to prioritize the determined policies and plan them according to the economic situation of the country. Hence, alternative energy policies have been prioritized objectively with scientific methods including the related institutions' evaluation. In this study, a model based on analytic network process, a group decision-making technique, is proposed for evaluating strategic energy policies. The model is used to assign priorities to strategic energy policies of Turkey. With this model, various people are included in the decision-making process and the effectiveness of the process is increased. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An experimental study is performed to determine the performance of a ground source heat pump (GSHP) system in the heating mode in the city of Erzurum, Turkey. The GSHP system using R-134a as refrigerant has a single U-tube ground heat exchanger (GHE) made of polyethylene pipe with a 16 mm inside diameter. The GHE was placed in a vertical borehole with 55 m depth and 203.2 mm diameter. The average coefficients of performance (COP) of the GSHP system and heat pump in heating mode are calculated as 2.09 and 2.57, respectively. The heat extraction rate per meter of the borehole is determined as 33.60 W m-1. Considering the current gas and electric prices in Erzurum city, the equivalent COP of the GSHP system should be 2.92 for the same energy cost comparing with natural gas. The virgin ground in Erzurum basin has high permeability and low thermal conductivity. In order to improve the thermal efficiency of GHE and thus improve COP of a GSHP in the basin, the borehole should be backfilled with sand as low-cost backfill material and a 1 to 2 m thick surface plug of clay should be inserted. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This study deals with evaluating the energy and exergy utilization efficiencies in the Turkish agricultural sector over a 12-year period from 1990 to 2001. In the energy and exergy analyses, two main energy sources, namely fuels and electricity, are taken into consideration, while the sectoral energy and exergy efficiencies are compared for this period. These main energy sources include diesel for tractors and other vehicles, and electricity for pumps. Overall energy utilization efficiencies are obtained to vary between 29.1 and 41.1%, while overall exergy utilization efficiencies are found to range from 27.9 to 37.4% in the analysed years, respectively. It may be concluded that the present technique proposed here may be used as a useful tool in analysing and evaluating the energy and exergy utilization efficiencies, identifying energy efficiency and/or energy conservation opportunities and dictating the energy strategies of countries. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Thermal stratification in a mantled hot water storage tank is analysed numerically for different water inlet velocities. The aim is to obtain higher thermal stratification and supply hot water for usage as long as possible. Twelve different water inlet velocities to the hot water storage tank are considered. The numerical method is validated by comparing its results against experimental and numerical results from the literature. It turned out that the results obtained from the numerical analysis have shown very good agreements with the results from previous works. As a result, the water temperature in the tank increases with the increase of the water inlet velocities to the mantle but this increment is not proportional. After a period of operation of 7.2 h, which corresponds to the average sunshine duration in Turkey, temperature increments of 6.5 and 35K have been estimated for the hot water inlet velocities of 0.01 and 0.3 m s-1, respectively, at a radial distance of 0.1 m and a height of 1 m inside the storage tank. [ABSTRACT FROM AUTHOR]