Search

The environmental impacts of energy production and consumption processes are becoming increasingly important as well as the limited resources of fossil fuels, as the demand for energy rapidly increases today. This situation emphasizes the importance of renewable energy and sustainability issues. Renewable energy sources such as solar, wind, hydroelectric, biomass and geothermal have a significant potential in meeting the energy demand. The utilization of these sources can enhance the energy security while they are reducing environmental impacts. The appropriate site selection decisions become crucial with the increasing demand for renewable energy sources. The Analytic Hierarchy Process (AHP) which is a Multi-Criteria Decision-Making (MCDM) method is preferred often as the effective tool in this process. The main aim of the study is to make a suitability analysis for the site selection of solar power plants (SPP). In this context, the spatial analyses for Denizli city is made using Geographic Information Systems (GIS) and AHP tools. Based on the expert opinions and related literature research, appropriate site selection criteria for solar power plants are determined. In addition, spatial and non-spatial data belonging to the study area are transferred to the GIS environment and analysis studies related to the study area are carried out. According to the findings, it is concluded that totally 44.579 hectares of land are highly suitable for SPP installation, totally 619.595 hectares are moderately suitable and totally 530.922 hectares are not suitable in Denizli Province. [ABSTRACT FROM AUTHOR]

In this study, the optimum panel tilt angles were determined monthly in order to benefit from solar energy more effectively for solar energy applications to be carried out in Iğdır province. For this purpose, the monthly average daily total solar radiation (HT) values on the solar panels were calculated according to the tilt angle of the panel. The tilt angle was changed from 0° to 90° in 1° increments for each month. The angle giving the highest HT value in each month was taken as the optimum angle. Then, the HT values at monthly optimum angles and the HT values obtained when the panels are placed horizontally, with latitude angle, latitude angle ±15° and seasonal average optimum angle were compared. While the optimum angle was obtained as 0° in June, it was observed that the optimum angle was 58° in January and December. Placing the panels with monthly optimum angles provided 0.02% to 55.61% more solar radiation to reach the surface compared to other conditions. Compared to the latitude angle, an energy gain of 13.35%, 20.89% and 17.46% was achieved in May, June and July, respectively. The lowest solar radiation gain was obtained in October, compared to the seasonal average optimum angle, and the highest gain was obtained in January, compared to the placing horizontally throughout the year. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) panels, which convert solar energy into electrical energy, generate non-linear, low-level direct current (DC) voltage. In this study, a DSP-based hybrid control method was proposed for the DC/DC boost converter to regulate the voltage of PV panels for high power applications. This proposed control method also includes perturb and observation maximum power point tracking (P&O MPPT) method. The output voltage was controlled with PI controller, and the current with average sliding mode (ASM) controller. The proposed hybrid control method was obtained by cascading P&O MPPT, PI, ASM controllers. With the proposed hybrid control method, while the PV panel was operated at the maximum power point, the output voltage and current were controlled by PI and ASM controllers, respectively. The input source of the DC/DC boost converter was modeled as FV panel and controlled with the proposed hybrid control method in the MATLAB/Simulink environment. The experimental setup was established for the proposed system and controller, and the experimental results of the system with 200V output voltage and 400W output power by DSP TMS320F28379D card were presented. [ABSTRACT FROM AUTHOR]

In this study, a photovoltaic system is simulated for maximum power point tracking using an artificial neural network. The interest in photovoltaic systems is increasing with inadequacy of fossil resources and rise in demand for energy. The variation of photovoltaic system performance depending on environmental conditions reduces efficiency. It is possible to prevent this by reaching maximum power point. Many techniques have been developed to operate system at maximum power point. With the spread of artificial intelligence, smart systems have started to be used in determining maximum power point. Artificial neural networks are intelligent systems that have the ability to learn, generalize and make decisions. In this study, maximum power point is determined with an artificial neural network whose inputs are temperature and radiation. The system was simulated in MATLAB/Simulink environment. A total of 1000 data were used in training of network in which Levenberg-Marquardt algorithm was used, 70% in training, 15% in validation and 15% in testing stages. It was observed that power of photovoltaic panel decreased from 225.1W to 46.9W, and power of boost converter from 220.9W to 45.75W when radiation was reduced from 1000W/m² to 200W/m² at regular intervals. When temperature was increased from 25°C to 45°C at regular intervals, it was determined that power of photovoltaic panel decreases from 225.1W to 194.6W, and power of boost converter from 220.9W to 190.7W. At constant radiation (1000W/m²) and temperature (25°C), system has the highest efficiency value of 98%. At constant temperature and different radiation conditions, it was seen that efficiency decreased as radiation value decreased. Similarly, under constant radiation and different temperature conditions, temperature increase caused a decrease in efficiency. The results show that photovoltaic system with artificial neural network based maximum power point tracking reaches maximum power point under changing environmental conditions. [ABSTRACT FROM AUTHOR]

Energy is crucial for economic, industrial, and social development. The increase in energy consumption is steadily rising. Fossil fuels, which cause greenhouse gas emissions, air, water, and soil pollution, are being replaced by sustainable and environmentally friendly renewable energy sources. Solar energy, which is the basis of renewable energy sources, can be used in both electricity and thermal energy production. In this study, the use of solar energy applications for meeting the electricity and heating needs of a two-person household under Ankara's climate conditions was examined, and an environmental analysis was conducted. The amount of energy that will be obtained by using photovoltaic panels, vacuum tube U-pipe solar collectors, and photovoltaic thermal panels separately and together was calculated. In addition, the effect of using Al2O3+CuO hybrid nanofluid in photovoltaic thermal panels as a working fluid on thermal energy transfer was investigated. As a result of the study, it was calculated that 11 panels with a power of 325 W would be required for meeting the energy demand with only photovoltaic panel use, and 7 panels with 300 W electricity and 600 W thermal power would be required for meeting the energy demand with only photovoltaic thermal panel use. Moreover, it was observed that using Al2O3-CuO hybrid nanofluid in photovoltaic thermal systems instead of pure water increased efficiency by 19.41%. It is recommended that the use of solar energy to meet energy needs will be both an economic solution by using a domestic energy source and an environmental solution by reducing greenhouse gas emissions, addressing the increasing natural gas problem in the world. [ABSTRACT FROM AUTHOR]

The human population in the world and in our country is constantly increasing. As a natural consequence of this increase, consumption is increasing. At the beginning of the increasing consumption is the need for energy. Many of the limited and decreasing energy resources on earth cause harm to the planet with their use. Thanks to these preferred environmental and sustainable energy sources, a reduction in environmental pollution and a slowdown in global warming are achieved. Solar energy is one of these environmental sources. In this study, a system design and theoretical analysis have been made to meet the heating and electrical energy needs of a house designed with a hybrid heat pump with PVT and environmentally friendly CO2 fluid. In the first stage, the heating energy need of the house designed in the study was determined. Afterward, the thermal and electrical analyzes of the PVT were modeled. Finally, the thermodynamic analysis of the heat pump was carried out. As a result of these analyzes and determinations made specifically for the designed system, findings in many parameters were obtained by comparing the system with both CO2 fluid and different fluids. The obtained findings are given in the thesis in graphic and chart formats comparatively. [ABSTRACT FROM AUTHOR]

With the increase in the world population, the need for food also increases, and accordingly, the importance of existing agricultural and pasture lands is better understood. While the world countries are making plans to increase the efficiency they get from their existing agricultural areas, the need for energy is increasing rapidly due to factors such as technology and industrialization. In order to meet the increasing energy need, all kinds of energy sources have been used until recently, ignoring the effects on the environment, but the limitation of resources such as coal and oil and the awareness of their negative effects on the environment has accelerated the orientation towards renewable energy sources. In this regard, wind and solar energy come to the fore. However, large lands are required for solar power plants, which creates a negative situation for limited agricultural areas. It is thought that the establishment of agrivoltaik systems or the preference of wind power plants in order to reduce the factors that suppress agricultural areas today, where the importance of agriculture and the need for agriculture are increasing, may benefit agriculture and animal husbandry. [ABSTRACT FROM AUTHOR]

The electricity grid is faced with the problems of insufficient investments, old infrastructure, line losses, low efficiency and energy quality. For this reason, many developed countries have begun to transition to micro and smart grid structures in which generation, consumption and storage are concentrated within a region. In this process, integrating local power generation resources into micro-smart grids will help energy supply. Among renewable energy sources, wind and solar energy are common and have a high application potential. In terms of local application, vertical wind turbines do not require towers, have low maintenance costs, and do not require a rudder system. These advantages increase when it becomes a hybrid system with solar energy. Especially in buildings where consumption is continuous, it is thought that these systems will contribute to the diversity in energy generation, even at a certain rate in the future. In this study, building integrated vertical wind turbine-solar hybrid energy systems (VWTS-HES) were examined, technical and economic analysis of the data was made with the HOMER PRO program in order to determine the most suitable renewable energy hybrid system to meet the electrical load, and suggestions were made in this direction. According to these results, it was concluded that Aktürk VWTSHES installation is the VWTS-HES with the lowest cost and the shortest depreciation period for 7 kW power, which is the monthly average electricity consumption of a family of 4, among the three VWTSHESs examined. In today's conditions, it has been seen that consumers can come together and turn to building-integrated VWTS-HESs so that consumers can contribute to the power system as producing consumers and micro-intelligent grid structures can develop, and VWTS-HES structures can contribute to the diversity of electrical energy generation. [ABSTRACT FROM AUTHOR]

Linear Fresnel collectors, which have a great potential to use solar energy more efficiently, need a validated simulation model in order to analyze their performance in the most accurate way during the design process. For this purpose, in order to understand the heat transfer capacity of the Linear Fresnel collector better, the geometric model and optical values of the system installed at Harran University GAPYENEV were simulated using both ANSYS Fluent and Tonatiuh. As a result of the simulations, the optical efficiency of the system and the radiation distribution on the absorber pipe in the receiver were found and compared. The amount of useful energy was calculated by finding the heat losses from the receiver. The thermal efficiency of the system was found by simulating the selected heat transfer fluid at constant flow and inlet temperature. The thermal efficiency of the linear Fresnel collector was found to be 0.348 with experimental data, while the thermal efficiency calculated with the ANSYS Fluent model was found to be 0.3223. [ABSTRACT FROM AUTHOR]

Determining where to install solar panels and power plants is a very complex and difficult to analyze spatial decision-making problem series. In order to solve this series of problems, Multi-Criteria Decision-Making methods integrated into Geographic Information Systems software have been preferred in recent years. This study aims to determine the areas with solar energy production potential in the Kars province. In the research, thematic maps were created for the purpose of processed research by obtaining data from various open sources in order to analyze the determined criteria that affect the location selection of areas with solar energy production potential. Based on the criteria weights calculated by AHP analysis from these maps, suitable areas with potential for solar power plant installation in the province of Kars were mapped in the GIS environment. As a result of the research, an area of 54,581 km2, which is very suitable and suitable for solar power plant installation in Kars province, has been determined and these lands constitute 55 % of the province’s surface area with a total surface area of 10,193 km2. The lands with potential for solar power plant installation in the Kars province show a homogeneous distribution. [ABSTRACT FROM AUTHOR]

The rapid development of technologies using renewable energy sources is paving the way for new solutions to meet the increasing energy and power needs of the industry. This study investigated the thermal and flow properties of a solar air heater used in food drying in the industry. The optimum efficiency of the solar air heater (SAH) was investigated for two different absorber plate lengths (1400 mm and 1820 mm). The energy and exergy efficiency values of both collectors were compared. ANSYS FLUENT 18.1 was used as a computational fluid dynamics (CFD) numerical analysis program in the study. Analyzes were performed at three different mass flow rates as 0.038-0.054-0.070 kg/s and 3-dimension (3D), respectively. For the accuracy of the CFD analysis, the experimental results with a mass flow rate of 0.038 kg/s were compared with the analysis results. Friction coefficients were calculated from the pressure drop obtained from the analysis. Temperature, velocity, and pressure distribution variations were shown for different times of the day. The highest thermal efficiency was realized at 13:00 at a mass flow rate of 85% and 0.070 kg/s. The thermal efficiency of the collector has increased with higher flow rates. Although the increase in the mass flow through the collector decreased the outlet temperature, the valuable energy amount increased. This study demonstrated that different mass flow rates and absorber plate size significantly affect the thermal efficiency of SAH. [ABSTRACT FROM AUTHOR]

Increasing energy demand around the world and meeting this demand from fossil fuels cause negative consequences such as global warming. For reducing the impact of these results, the use of renewable resources is gaining importance. Heating of buildings is a high energy dependent process, thus benefiting from solar energy is advantageous for locations with a long hours of sunshine. Manisa is also advantageous in terms of sunshine duration. One of the solar heating applications is the Trombe wall. In this study, a classical Trombe wall (Type-1) and a different type of Trombe wall (Type-2) were designed and these two types of walls were compared in terms of energy, economic and environmental aspects. During analyzes, the air channel depth and the variation of solar radiation intensity, which are important parameters for Trombe walls, are discussed. As a result of the calculations, the energy efficiency for Type-1 and Type-2 walls was found to be 0,37 and 0,46, respectively, at the optimized operating parameters for January (for 500 W/m2 solar radiation intensity and 0,35 m air duct depth). Again with these parameters, it has been calculated that the indoor temperature rises to the maximum values of 19,6 oC and 21,8 oC for Type-1 and Type-2 walls at 15.00. Economic analysis indicated that payback period of the Type-1 and Type-2 walls are 7,3 and 6,9 years, respectively. It has been calculated that the use of Type-1 and Type-2 walls provides a reduction of 5985,5 kg and 6405 kg in total carbon emissions, respectively. [ABSTRACT FROM AUTHOR]

Due to global warming in the world, energy production systems connected to fossil energy sources are gradually decreasing. Due to this, the use of renewable energy sources is increasing. Solar energy is one of the most important renewable energy sources. In order to meet the increasing energy needs, the use of solar energy in photovoltaic systems is increasing rapidly. Studies for the use of solar energy in thermal systems are also continuing to increase. The parabolic solar collector stands out among the thermal energy applications. With these collectors, it is possible to produce heat energy up to 300 oC temperatures. At this temperature, electricity can be generated by heat energy. On the other hand, in summer, when cooling energy is very much needed, cooling can also be done with absorption cooling systems using abundant solar energy.. High coefficient of performance(COP) can be obtained in double-stage absorption cooling systems with high temperature heat energy. In this study, the instantaneous thermal performance of parabolic trough type solar collectors was investigated by modeling. For this, a simulation program has been written in the MATLAB programming language. In this program, the DPP model was used to calculate the instantaneous direct solar radiation value(DNI). With the calculations made using this model, it has been shown that it would be appropriate to place such collectors, which follow the sun in one dimension, in a North-South direction so that they can produce more energy.Using the characteristics and dimensions of a sample collector, instantaneous efficiency and useful heat calculations were performed. Daily, monthly and annual thermal power values and efficiency calculations were made with the sum of these instantaneous values. For the regions selected as an example, comparisons were made by finding annual thermal power values depending on environmental parameters. The ideal environmental parameters for the installation of such systems have been determined and discussed. [ABSTRACT FROM AUTHOR]

Today, increasing energy costs bring the efficient use of energy to the agenda in the textile sector as well as in all sectors. The use of renewable energy sources in the production process will continue to occupy an important place in energy production as it is an inexhaustible and domestic energy source with low cost values compared to traditional fuels. Solar energy maintains its importance as the most preferred renewable energy source for domestic and industrial use due to its high potential. In this study, grid-connected and off-grid photovoltaic system designs were carried out using the HOMER Pro program in order to meet the electricity needs of a textile factory located in Bursa Demirtaş Organized Industrial District (DOID). As a result of the study, it was decided that the off-grid photovoltaic system was the most suitable system for the factory, and the net present cost of the system to be installed was determined as 2,625,139,000 TL ($ 151,654,477.2) and the simple payback period was determined as 14.04 years). [ABSTRACT FROM AUTHOR]

As a result of the rapid decrease in fossil fuels and increasing energy demand, countries have turned to alternative energy sources. Renewable resources, which are alternative to fossil resources and are environmentally friendly, are clean and inexhaustible energy resources. Solar energy is one of these alternative energy sources This study; With the RetScreen program, it is aimed to analyze the suitability of the system and observe its performance before the PV system is installed. Features affecting the performance of PV systems; It has been designed by considering factors such as the position of the panel, the angle of inclination, shading and panel type. Shadow analysis was performed with the Helioscope program. In the shadow analysis, firstly, the geographical location is defined and the determined parameters are entered into the system. Technical, energy and economic analysis of the 14 kW solar system for the Ziraatbiyotek building was made. The analysis was made in 2 different scenarios and the positive and negative aspects of the solar system to be installed in the building were revealed. The Ziraatbiyotek building, where the study was carried out, was established in the Naip District of the Süleymanpaşa district of Tekirdağ province. For the Ziraatbiyotek laboratory building, 60 panels of the GES power plant with an area of 405 m2 were used. The brand of the selected panel is Astronergy Solar and each has a power capacity of 240 W. The panel inclination is 30° and the azimuth angle is 0° in the RetScreen program. Polycrystalline was used as the panel type in two different scenarios. In the first scenario, emission reduction support was not included and the payback period of the system was 10.4 years, and in the other, $15 tCO2-1 and annual support of $142 were included and the payback period of the system was 9.8 years. According to the results obtained with the program, 20.1 Wh energy produced by the solar panel system decreased 9.5 tCO2 greenhouse gas emissions. It has been obtained that if a 14 kW solar energy system is installed in the Ziraatbiyotek building, approximately 40% of the annual electricity need will be met from solar energy. [ABSTRACT FROM AUTHOR]

The importance of clean energy resources has increased with the gradually decrease of energy resources and increasing environmental conscious. Hydrogen energy, comes at the forefront of environmentally friendly energy sources, can also be produced from hydrogen sulfide which is abundant in the bottoms of the Black Sea. The Black Sea has a great energy potential with a hydrogen capacity of 270 million tons. In this research, a study has been carried out that the energy required for the production of hydrogen from hydrogen sulfide at the bottom of the Black Sea by direct electrolysis method can be obtained from renewable energy sources on the Black Sea coast. A plant design which can produce 50 tons of hydrogen per year with approximately 640 MWh obtained from solar and wind energy on the Black Sea coasts has been considered. It was concluded that a hybrid system that can benefit from both solar and wind energy could be established in Istanbul and Zonguldak Filyos as a result of the solar and wind energy potential analyzes and economic analyzes were carried out in order to investment evaluation in these locations. Net present value method and internal rate of return method have been preferred and two different scenarios where the investment is realized by receiving 100% loan or by receiving 25% equity capital and 75% loan are discussed. Investment feasibility assessment and profitability ratios for both Istanbul and Filyos seem to be quite good, and it has been observed that the payback period of solar power plants is shorter compared to wind power plants. [ABSTRACT FROM AUTHOR]

In this study, thermodynamic modeling and analysis of geothermal and solar-assisted cogeneration energy systems to supply the electricity and heating requirement of residences in Afyonkarahisar province are performed. In the system considered, electricity is generated in the Organic Rankine Cycle (ORC) with thermal energy obtained from geothermal and solar resources. The generated electricity is given to the network according to the energy requirement. When the grid's energy requirement is low, the excess electricity is sent to the electrolysis unit, and hydrogen is produced and stored. When energy is required again in the grid, the fuel cell's hydrogen energy is converted into electrical energy and given to the grid. The heat energy released from the cycle as waste heat in the ORC cycle is used in residential heating. The thermodynamic performance evaluation of the system has been performed in the Engineering Equation Solver (EES) software using the geothermal and solar energy values of Afyonkarahisar province. The parametric study of the system is carried out at different geothermal source temperatures and solar radiation values. In Afyonkarahisar, the geothermal water temperature is between 70 and 130°C, and the mass flow is between 70 and 150 kg/s. Also, solar radiation varies between 300 and 1000 W/m2. Total power generation in geothermal and solar assisted ORC cycle is 2420 kW. If this power generation is used to generate hydrogen directly in the electrolysis unit, 0.0154 kg/h of hydrogen is generated from the system. The heating capacity of the system for residential heating is 8933 kW. The overall system's energy and exergy efficiency has been calculated as 34.5% and 46.0%, respectively. [ABSTRACT FROM AUTHOR]

The world's population growth and advanced technology processes lead to a higher need for energy in an annual context. Fossil-based resources such as coal, natural gas, oil, which are gradually decreasing, are frequently used to meet the increasing energy demand. Therefore environmental pollution reaches dangerous levels. The use of renewable energy sources, not requiring imports besides their low costs, is vital in resolving the environmental pollution in Turkey. This study examines the potantial of 50MW solar power plant in the Sincan district, Ankara province, for investment. It seems possible that solar power plant investments might recover the investment made within 4-5 years and produce energy for 25 years, which is the economic life of photovoltaic systems while reducing carbon emissions. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) power plants, which are one of the most important renewable energy sources, provide great opportunities in terms of clean energy, due to their almost zero harmful environmental impact and relatively easy installation, considering the solar potential of our country. In addition, the government supports offered within the scope of the Renewable Energy Resources Support Mechanism (YEKDEM) provide great opportunities to bring renewable energy resources into the economy. According to the projection made in the annual program of the Presidency of our country, an increase of 1000 MW is expected in the amount of electricity produced from solar power plants in 2022. In addition, the share of electricity produced by solar energy in the total production is expected to be 8.5%. In this study; the design and simulation application of a rooftop, grid-connected distributed solar power plant with a capacity of 1MWp was presented through the PVsyst program. In the study, it was seen that the panel slope, the right PV module, and inverter selection are essential. The annual amount of energy that can be supplied to the grid has been obtained as 1246 MWh. In the simulation studies, it was emphasized that such a facility, which was established compared to a power plant with equivalent energy production, would contribute positively to the impact of climate change by not emitting 14000 tons of Co2. It has been observed that revenue of 4,485,600 ₺ can be obtained from such a newly established facility for the first ten-year period with a fixed fee purchase guarantee with the domestic contribution. Considering that the life of the power plant will be 25 years, it can be said that the facility investment will be highly advantageous even without YEKDEM support. [ABSTRACT FROM AUTHOR]

With the developing technology and industrialization, electrical energy consumption is increasing every year. It is important that the electrical energy produced against the increasing demand is among the new and renewable energy sources. While factories go to produce their own electrical energy, these situations can also negatively affect energy quality. In this study, the problems related to energy quality in the solar power plant that a textile factory built with a self-consumption model were analyzed in detail and measurements were made. Detailed information about the measurement method and how the measurement is carried out is also shared. The problem in energy quality also negatively affects the production performance of the solar power plant and causes low production. Since the improvement of the production performance depends on the improvement of the energy quality, solution suggestions are also presented for the improvement of the energy quality. [ABSTRACT FROM AUTHOR]

The 1973 oil crisis caused the price of a barrel to rise from $2.59 to $11.65. There have been many oil crises since 1973. These crises have led countries around the world to seek alternative solutions. As a result of the researches, orientation towards renewable energy sources has emerged as a solution. Renewable resources are inexhaustible and cleaner energy sources than fossil fuels. Among the renewable energy sources, solar energy is the most promising source. Solar energy is distinguished from other renewable energy sources by its ease of use, ubiquity and being the cheapest energy at the same time. There are many different technologies and methods to generate electricity from solar energy. The most efficient and common technology for generating electrical energy is to run a turbine by concentrating the sun's rays in one place and obtaining high temperatures. Parabolic trough type solar collectors are at the forefront of this method. In this method, direct sunlight is concentrated by reflecting it to the receiver pipe, which is placed across the focal point of the parabolic collector, thanks to a reflective surface. In this study, a theoretical study was carried out in order to find a solution to the energy problem of the Comoros Islands, which are dependent on foreign and fossil fuels for energy supply. In this study, information about the Comoros solar energy potential, solar radiation and the equations required for the calculation of solar radiation and concentrator systems are given. In addition, the equations required for sizing the parabolic trough type solar concentrator and calculating the thermal and optical losses in the system are explained in detail. Then, calculations of electrical energy production in Comoros were made with a parabolic trough type solar collector. Parabolic trough solar concentrator system with 400kWe installed power and ORC turbine power generation system have been used for electric power generation in Comoros. Finally, the calculations and analyzes were evaluated and the suitability of this system in the Comoros Islands was demonstrated. [ABSTRACT FROM AUTHOR]

Today, the increasing energy need in Turkey is mostly met from imported energy sources. The disadvantages of imported energy sources are also known as economic and ambient impacts. Although the solar energy potential of our country is high, its share in electricity production is quite small. Along with the developments in the field of technology and materials, there are innovations in photovoltaic panels and improvements in their efficiency. One of the many factors affecting the efficiency of photovoltaic panels is the surface temperature. In this study, the surface temperature was analyzed depending on the annually ambient temperature and the solar radiation values in Denizli province. The effect of surface temperature on panel output power and efficiency has been revealed. The efficiency decreases linearly as the surface temperature rises, and this decrease is approximately 0.3% with a temperature increase of 5 ºC. [ABSTRACT FROM AUTHOR]

The fact that the refrigerant pairs used in absorption refrigeration systems do not have harmful effects on global warming and ozone layer makes absorption refrigeration g systems advantageous compared to vapor compression refrigeration systems. In this study, a comparative analysis of the system elements of the absorption refrigeration system, which is accepted to work with LiCl-H2O, LiBr-H2O and NH3- H2O working pairs, according to the different operating temperatures within the scope of the 1st and 2nd law of thermodynamics was made. In addition, in the study, incoming solar radiation values have been calculated for the province of Antalya, where the absorption refrigeration system is assumed to work from solar energy. In the study, the analysis of the absorption refrigeration system working with three different vacuum tube collectors and LiBr-H2O pairs has been made. In the analysis, collector efficiencies, required collector areas and the solar fraction values and collector areas required for economical operation have been calculated. Obtained results are given in tables and graphs. [ABSTRACT FROM AUTHOR]

The limited reserves of fossil resources, the fluctuations in their prices and the damage they cause to the environment have led countries to seek alternatives to primary energy resources. Solar energy, which is an unlimited and environmentally friendly resource, is a powerful alternative to other energy sources. The majority of the European Union countries offer various opportunities to consumers in electricity generation from solar energy with many incentive mechanisms and ensure their widespread use. In many parts of the world, interest in renewable energy sources such as solar, wind, hydrogen and geothermal is also growing. In addition to all these, researches are continuing to use alternative energy sources and to make energy production more efficient. The radiation value required to obtain electricity from solar energy varies according to the weather conditions during the day and seasonal characteristics. The climatic conditions in the area where solar power plants are installed directly affect the output power and energy cost to be obtained from photovoltaic panels. Estimating the output power produced from photovoltaic panels according to environmental conditions, guiding companies in the installation of solar energy systems, obtaining maximum energy, energy management and efficient operation of the system are of great importance. In this study, feedforward back propagation artificial neural networks and KNN (K-Nearest Neighbors) methods were used to estimate power values using the data (Temperature, Humidity, Pressure, Radiation) obtained from the installed photovoltaic panels. Thus, the panel values obtained under real field conditions were trained with both methods and the results were compared. As a result, the power values of the panel were classified using the artificial neural network model developed with the highest accuracy of 98.7945%. It has been seen that the machine learning models used for solar energy estimation developed within the scope of this study have high performance and can produce results very close to the real values. In addition, it was concluded that both artificial intelligence models developed in locations with different characteristics according to the determined load demand can be used. [ABSTRACT FROM AUTHOR]

In this study, a photovoltaic system located in on one horizontal ("UPPER") and four different vertical surfaces ("EAST", "WEST", "SOUTH", and "NORTH") surfaces has been established to measure the solar radiation coming from different directions. All data measured in unit of volt were collected minutely during one year (April 2020 to March 2021). Photovoltaic data were calibrated in unit of W/m2 with using the data measured simultaneously from 8-48 Model B&W Pyranometer. Using the R2 and RMSE statistical methods, the solar energy data from the "UPPER" photovoltaic and the pyranometer were compared with each other and it was found that R2=95 % and RMSE=40.10 W/m2. The monthly annual total (mean) solar radiation components in the "UPPER", "EAST", "WEST", "SOUTH", and "NORTH" orientations were measured to be 4210.98 W/m2 (mean 350.92 W/m2), 1345.79 W/m2 (mean 192.26 W/m2), 2780.92 W/m2 (mean 231.74 W/m2), 3577.94 W/m2 (mean 298.16W/m2) ve 1200.93W/m2 (mean 100.08W/m2), respectively. [ABSTRACT FROM AUTHOR]

The intermittent and variable nature of solar energy makes its efficient use very difficult. The biggest factor in this intermittency and variability is cloud movements. In the study, the performance of a flow-based algorithm for tracking and predicting the movements of clouds was investigated under the conditions of the Afyonkarahisar region. For this purpose, a digital camera was installed in Afyon Kocatepe University Engineering Faculty and sky images were recorded at regular intervals. Cloud and sky classifications were made on the images obtained. In order to follow the clouds, the most suitable corner points for tracking were determined using the Shi-Tomasi algorithm. The corner points found were followed on sequential images using the Lucas-Kanade optical flow algorithm and the motion direction and speed information of the clouds were obtained with the help of linear regression. Finally, using the relevant motion direction and velocity information, cloud motions with a resolution of 20 seconds for a time horizon of 340 seconds are estimated. For the data set used in the study, estimates were made with an error performance of 5.88%. The method has shown that it has a high potential in cloud motion prediction. [ABSTRACT FROM AUTHOR]

In order to reduce the drawback of intermittent operating conditions in systems using solar energy, it may be possible to store solar energy during hours when sunlight is sufficient and then using it in heating applications with a thermal energy storage system (TES). In this context, TES applications can be widely used to ensure the sustainability of solar energy. In this study, basic elements of sensible heat energy storage (STES) system, which is one of these methods, were comprehensively treated first. Next, energy analysis relations of this system are presented. Some applications of STES were then decribed. Finally, main concluding remarks were given while some recommendations were made. It may be concluded that one of the most critical parameters for evaluating the thermal behavior of the sensible heat TES tank is thermal stratification. [ABSTRACT FROM AUTHOR]

Besides the most common uses of antimony metal and / or compounds, with the development of solar energy technologies, the need for antimony and its compounds increases and the rapid depletion of primary sources in the world increases the importance of antimony recovery from secondary sources. The recovery method proposed in this study aims to reduce the ionic antimony by oxidation of the more active metal and to produce metallic antimony in powder form as a result of reduction process. Oxide based antimony containing ore has been treated by acidic solutions. But as the recovery rate was too low, the parameters affecting the metallic precipitation of antimony from acidic synthetic antimony solutions which are a secondary source were examined in detail. The physical and chemical properties of antimony metal were determined after examining reaction time, temperature, initial antimony concentration, zinc powder amount and solution pH parameters during cementation process which could affect experimental working conditions. As a result of the experimental studies, using 25 mL of 1000 ppm Sb3+ synthetic solution with the addition of 100 mg of metallic zinc and mixing speed of 60 rpm, recovery efficiency of up to 100% was achieved in a noticeably short time such as 5 minutes and metallic antimony of 99% purity was obtained. When 100% recovery was achieved with zinc of 100 mg in single-stage cementation, the same yield was achieved with the addition of 40% less zinc in two-stage cementation. [ABSTRACT FROM AUTHOR]

The emission of carbon dioxide (CO2), which is the biggest factor in global warming, increases the use of both electricity production and heating with the developing technological innovations and increasing population. The poor thermal insulation of some buildings and the high losses due to electricity transmission and distribution ensure that the rate of electricity consumed in residences remains high. In this study, with the smart application of the translucent-building-integrated photovoltaic system working with the effect of the Trombe wall in the model rooms, it provides maximum efficiency from the sun by using the solar energy both actively and passively at the same time. As a result, it provides both thermal insulation and electricity generation in buildings. Two model rooms are prepared and the 0.4°C accuracy temperature sensor of the semi-transparent photovoltaic system working with the effect of the Trombe wall is prepared and the data collecting card is produced using Arduino mega 2560 and calculated. In the first experimental study carried out in a difficult period such as February to May, only 14.93 kWh of energy could be produced due to the steep angle of the solar panel and the lower efficiency of the semi-transparent cell structure than its counterparts. Data are collected separately from the two model rooms, and their differences are examined in detail and it is seen what alternative models could offer. Energy savings of 100 kJ in February, 77.85 kJ in March, 97.66 kJ in April and 49.93 kJ between 1-10 May and 325.44 kJ in total 92 days are achieved. Thus, separate data are collected from the two model rooms and their differences are examined in detail and it is seen what alternative model could offer. [ABSTRACT FROM AUTHOR]

Energy is an important resource for the future of human beings. It is an indicator of development and sophistication. With the increase in the population and the development of technology, the need for energy has also increased. Because of limited fossil resources in energy production and in order to keep environmental pollution at minimum, renewable and environmentally compatible resources should be preferred and developed. Solar energy is one of the energy sources with high potential among renewable energy sources. Location selection is very important issue for solar energy as negative effect of a wrong location selection will be high because of high investment costs and agricultural land invasion. The aim of this study is to determine the most suitable location for the solar power plant within the boundaries of Karaman Başyayla, Konya Taşkent ve Niğde Bor. 8 criteria that affect the right location selection have been determined and criterion weights were found with Entropy. By using TOPSIS, MOOSRA and ARAS methods, it has been tried to determine the most suitable location for the solar power plant planned to be built in the regions above. Konya Taşkent alternative ranked first in all methods, while Karaman Başyayla alternative ranked second and Niğde Bor alternative ranked third. [ABSTRACT FROM AUTHOR]

The amount of electrical energy to be obtained from solar energy systems varies greatly depending on the solar radiation value. The design and planning of a solar energy system are possible by knowing the radiation value. Since solar radiation intensity has a highly variable structure throughout the day, it is very difficult to capture these changes using a single prediction model. In this context, in recent years, different hybrid models and approaches have been proposed by researchers to overcome the limitations of single models and increase predictive accuracy. In this study, the applicability and performance of the method were investigated by using the Decomposition-Ensemble learning approach, which is a hybrid approach to the estimation of solar radiation intensity data. In addition, it is aimed to increase the time resolution of forwarding solar radiation forecasts. In this context, 15-day solar radiation value was forecasted hourly, using an annual solar radiation data measured hourly with a pyranometer located within Afyon Kocatepe University, Solar and Wind Energy Application and Research Center. In the learning approach, Empirical Mode Decomposition (EMD) method is used for decomposition and Least Squares Support Vector Regression (LS-SVR) method is used for individual predictions. The most appropriate parameter values of LS-SVR models were determined by using a grid search algorithm and 5 fold crossvalidation methods. The results obtained from the study showed that the Decomposition-Ensemble learning approach is successful in estimating solar radiation data. [ABSTRACT FROM AUTHOR]

Photovoltaic systems, which is one of the subjects that many developed countries are working on, are used to obtain electrical energy from solar energy. Photovoltaic systems have emerged as one of the most reliable and affordable alternatives to meet energy needs. In case of meeting this energy need, examining the conditions such as partial shading depending on the time is vital for meeting the energy. The shading situation causes the power obtained to decrease significantly. As the shading rate increases, the efficiency decreases. Therefore, for different conditions, the effect of the shading situation on the power obtained must be investigated. This study was done in a laboratory environment by using solar simulator. The distance between the artificial light source and the panel is set at 0.8 m and 1.4 m, and the angle is 0 °, 20 ° and 40 °. In case of shading to the all cells and shading to 1/36, 2/36 cells, in terms of panel characteristic and change of maximum power are compared. The results showed that the maximum power obtained decreases as the distance and angle between the artificial light source and the panel increases. [ABSTRACT FROM AUTHOR]

In solar energy systems, due to the low efficiency in energy conversion, efforts to increase efficiency have gained importance today. Maximum Power Point Tracking (MPPT) systems have been developed to use solar energy systems at maximum efficiency. In this study, the effect of a frequently used maximum power point tracking algorithm on efficiency is investigated. Using Matlab/Simulink, a system that includes a solar cell module and Boost DC-DC converter is designed to detect the maximum power point in variable atmospheric conditions. This system is operated with maximum power point tracking unit and without maximum power point tracking unit, and the obtained results and their effects on efficiency are compared. The system has been studied in three different situations. In the inferences obtained, it was observed that the efficiency increased from 72.6% to 92.95% in the first working condition, the efficiency increased from 90.59% to 96.43% in the second working condition, and the yield increased from 92.27% to 94.46% in the third working condition. [ABSTRACT FROM AUTHOR]

In this study, an algorithm has been created to optimally sizing a photovoltaic pump system. The sizing algorithm works based on the energy balance in the system. The algorithm is suitable for the sizing of both battery-powered and battery-free photovoltaic (PV) pump systems. For PV pump systems containing batteries, optimization takes place using the iteration method with the balance of energies charging or discharging the battery. Optimization for battery-free systems is based on the availability of PV panel area to meet the energy used by the pump. The algorithm created in the study was applied for corn plant in 1 hectare area in Manisa - Salihli district in July. It is assumed that drip irrigation method is used for watering the plant. In addition, after the necessary assumptions are made for the well, the power of the pump is added to the calculations as 1.5 kW and the flow rate is 9,55 m3 /h. As a result, it was calculated that a total of 23 panels are required within the system with battery and on the other hand, 36 PV panels are required in the absence of a battery. In addition, the required battery amount was found to be 3. According to these results, if the battery is used in the system, the amount of PV panels required is reduced significantly. In addition, another important result is that half the amount of potential energy that the PV panel can obtain is wasted if there is no battery in the system. However, if the battery is used, this energy to be wasted is collected by the batteries and the system is provided to become more optimized. [ABSTRACT FROM AUTHOR]

In this study, solar energy supported basil drying system was designed and manufactured while conducting purple basil plant drying experiments. The experiments were carried out in three groups. In the first group of experiments, basil having were placed in the drying chamber and when the temperatures reached 45°C, 50°C, 55°C, the mass was measured at one hour intervals. In the second group of experiments, when the temperature reached 45°C, 50°C, 55°C, 60°C in the dryer, basil having were put into the dryer and dried. In the third group of experiments basil having a starting mass of different were placed in the drying cabinet and dried. Drying times were between 3 and 7 hours depending on the temperature increase. After the completion of drying process, water activity and color analysis of the dried products were performed. The final moisture content of dried basil is reduced to less than 15%. Water activity values have been found below the 0,6 value specified in the literature and it has been concluded that it can be accepted as safe in terms of microbial growth. Drying times were found as expected in experiments at different temperatures. Color analysis experiments were carried out and required values were reached. As a result of the analysis, it was found that the manufactured system successfully enables the drying of basil. [ABSTRACT FROM AUTHOR]

Energy is a constant need and this need is a growing resource. Renewable energy, which is one of these energy sources, is very important for our world to be both clean and sustainable. One of the central belt countries in the world, Turkey is a very fortunate country in terms of renewable energy sources. In this study, a model for solar energy source installation and energy efficiency has been proposed for Erzurum, Erzincan, and Sivas. This model has been solved by deterministic and robust optimization. Pursuant to the results obtained from the solutions with these methods, the most suitable location has been determined. At the end of the study, it has been found out that Erzurum is the most suitable city for the selection of the location according to both solutions. According to deterministic solution for Erzurum, the efficiency has been observed between 83950724.1 and 87591854.81 while it has been between 83416034.92 and 87065524.19 according to robust solution. There has been an approximately 0.618% difference between these two solutions. [ABSTRACT FROM AUTHOR]

This study aims to analyze the evaluation process of this source in the energy portfolio by Turkey which has a strong potential in terms of solar energy as well as examine solar energy applications, opportunities and risks in the context of Karabük as a local sample. Qualitative research method was used in the study. This research is a case study. In the research, it was thought that qualified and indepth information would be obtained from the authorities in the sector and from one of the purposeful sampling methods, the criterion sampling method was used. In this direction three themes emerged as the future of solar energy in global energy portfolio, advantages, disadvantages and future of solar energy in terms of Turkey, the advantages of Karabük province in terms of solar power plant (SPP) and SPP applications in Karabük province. In the study, it was found that the reason of more widespread of the application of SPP lands with roof and the side surface (front) in the general practice of Karabük and Turkey does not depend only on radiation values but also depends on the course of national energy policies, production of energy technologies, initial investment costs, related legislation, incentives, subsidies, transmission and distribution infrastructure, procedure processes and various geographical criteria for investing in the resource in question. As a result, although solar energy has been growing within the scope of investments, in energy policies on a global and national scale based on projections; fossil fuels, nuclear energy, hydraulic energy, wind energy, hydrogen energy will also play an active role. [ABSTRACT FROM AUTHOR]

This study presents a design and development of hybrid forecasting model by using ARIMA and artificial neural networks for short-term energy forecasting processes in energy management systems. Proposed model is applied into a company operating in the tobacco products manufacturing industry and reliability of the model is tested by using real-life data set in illustrative cases. In line with the results obtained from ARIMA method, some of the factors affecting electricity consumption are taken into consideration as input data for artificial neural network model. After considering the correlation between solar energy generation, working hours, production quantities and past electricity consumption data, various number of neurons and different training algorithms are tested to design the optimal system for the company. The proposed hybrid model provides around 39.9% improvement compared to forecast data obtained by using only ARIMA model. [ABSTRACT FROM AUTHOR]

Solar air collectors are generally used for drying industrial and agricultural products or for space heating. Nowadays solar energy is paid more attention due to decrease in fossil fuels and increase in energy prices. In this study, a single pass, forced convective solar air collector has been designed, manufactured and analysed experimentally under climatic conditions of Konya/Turkey. Experiments have been conducted at three different mass flow rates, on different days and under clear weather conditions. Hourly variation of solar radiation, inlet and outlet air temperatures, glass cover temperature, absorber plate temperature and thermal efficiency of the solar air collector have been examined by using the experimental data obtained. It is seen that with the increase in mass flow rate, temperature of the air at the outlet of the collector decreases while thermal efficiency of the collector increases. [ABSTRACT FROM AUTHOR]

Today, solar energy has become an indispensable element in providing energy infrastructure. Estimating the solar energy potential of building roofs in residential areas is important for the effective use of this energy. Nowadays, thanks to the developments in artificial intelligence algorithms, these tasks are performed automatically by computers. In this study, a solution is proposed by using deep learning architectures, which are the most advanced artificial intelligence algorithms. Convolutional Neural Network model called Roof-KSA with less parameters was proposed for semantic segmentation of building roofs in this research. A total of 3400 satellite images in 224x224x3 pixels size were used for semantic segmentation. Roof-CNN model has a total of 10 layers and 104,450 updated parameters. Within the scope of comparative analysis, Roof-CNN model has less parameters compared to U-Net models. In addition, Roof-KSA model stands out with 0.91404 global accuracy, 0.73092 mean accuracy, 0.65537 mean intersection over union, 0.84918 weighted intersection over union and 0.67244 mean BF score. As a result, it is seen that Roof-CNN model is more successful in accordance with obtained semantic segmentation results. [ABSTRACT FROM AUTHOR]

In terms of renewable energy sources, our country has a much bigger energy potential compared to many developed countries. Especially in terms of solar energy, our country is among the countries with the greatest solar energy potential among other countries. The base stations of GSM operators bring a significant cost to our country in terms of energy transport line and energy consumption in rural and mountainous areas. For this reason, especially in rural areas away from the center, GSM base stations can be supplied with solar energy to meet their economic needs. In this study, a sample base station system which is fed with solar energy in Isparta province is designed. Battery capacity and number of panels were determined and cost analysis was performed. In case of using PV with solar energy in base stations, system cost is high. However, it was observed that the use of PV saved 41% of the energy costs of the base station during the sun-drenched summer months. [ABSTRACT FROM AUTHOR]

This study investigates the effective solutions for the rational utilization of solar energy in dense cities of vertical urbanization. Taking into account the high embodiment of energy and exergy of transparent PV cells mounted on glass facades and structural aluminum material with associated embodied CO2 emission responsibilities, it has been concluded that in high-rise buildings with glass facades along with other physical constraints, exergy and energy-rational utilization of solar energy is not possible. Furthermore, it is stated that legal issues may arise due to solar shading on neighboring buildings. By providing tangible examples, it has been shown that in addition to solar energy, wind, geothermal, and biogas energy systems may be integrated towards hundred-percent renewable cities by employing a carbon-related city-planning model. This paper further emphasizes that the most rational way to utilize solar energy is to develop and diffuse district energy systems into the built environment with hybrid renewables by focusing on a comprehensive decarbonization model. This model indicates that low-rise buildings are more rational, although horizontal cities bear higher investment and operational costs of the wider infrastructure and associated additional CO2 emissions. The paper concludes that there should be an optimum city planning decision-making model by introducing a new metric. This decision-making mechanism is indexed to total CO2 emissions and is called the Optimum Urbanization Model. Additionally, a conceptual design of a hydrogen home with solar and wind energy is presented. [ABSTRACT FROM AUTHOR]

In this study, the thermodynamic and economic analysis of the hybrid power plant obtained by integrating Linear Fresnel Reflectors, which is one of the systems used in the concentrating solar power plants, to an existing coal-fired power plant was carried out. When thermodynamic effects were examined, specific dates, time, solar radiation, solar field and load factor were taken as parameters. Firstly, the area of the solar power plant was determined by thermodynamic optimization. Then, solar energy share in annual electricity generation and fuel and emission savings are calculated within the framework of specific scenarios. As a result of thermodynamic analysis, it has been found that placing the solar field parallel to the high pressure preheaters is the most feasible solution. In economic calculations, the investment payback period was found taking into account emissions and fuel savings and the share of solar energy in annual electricity generation. The effect of the solar field unit investment price and emission unit price on the payback period has been examined. The maximum annual fuel and emission savings were found for Scenario 7 as 7003,667 t/year and 7748,849 tCO2/year, respectively. It has been found that the payback period could be 7 years if the unit price of the solar field is 132 €/m2 or the support price for renewable energy is 0,225 €/kWh. As a result, in the coming years financially of this hybrid system to be implemented in Turkey it has been shown to be much more economical. [ABSTRACT FROM AUTHOR]

Increasing global energy demand and fluctuating costs drive mankind to sustainable and cost-effective energy solutions. Renewable resources and relevant energy-generating technologies stand out as sustainable and eco-friendly options. In recent years, with a significant decrease in energy production costs, solar energy has come to the fore and increased its production share in the national economies. Solar based electricity production technologies are preferred not only with their cost-effectiveness but also with their contribution to combating climate change and achieving sustainable development targets. In this context; the aim of this study is to analyze the techno-economic and environmental aspects of a system consisting of photovoltaic (PV) modules that use solar energy as a source to provide electrical power demand in a campus located in Istanbul. The solar potential of the Turkish Naval Academy of the National Defense University has been calculated based on the available rooftop area for PV modules in the campus, the availability of per unit area of the roof, the efficiency, inverter efficiency and temperature effects on the PV array's performance. The potential of the roof-mounted PV system was calculated using a modified calculation and then the feasibility of the proposed energy system has been developed by the RETScreen simulation tool. As a result, it is calculated that the proposed system will reach positive cash flow at the end of four years repayment period and continue its profit condition throughout the 25 years project life cycle, which will decrease the total greenhouse gas emissions by 93% and save 721.1 tons of crude oil. It has been evaluated as a cost-effective and environment-friendly application for the campus of the Turkish Naval Academy. [ABSTRACT FROM AUTHOR]

In this study, the thermodynamic performance of solar collectors (FPSCs) and vacuum tube solar collectors (VTSCs), electricity and hydrogen production were numerically compared. Both systems were analyzed for one year in Adana climate conditions. FPSCs and VTSCs are solar energy technologies that can produce heat energy from solar energy. They are used in various places to meet the need for hot water or warming. However, today electricity is used more in many places, electricity generation is becoming more valuable every day. Thus, humanity seeks to produce electricity from various sources. Organic Rankine Cycle (ORC) is a very important machine that can produce electricity from sources at low and high temperatures. In this way, the heat energy produced in the FPSCs and VTSCs was transferred to the ORC by means of a pump and electricity was generated. The electricity produced in the ORC was transferred to an electrolysis system where hydrogen was produced by electrolysis of water. The thermodynamic analysis of the system was carried out by the Engineering Equation Analyzer (EES) simulation program. According to the results, with the increase of the solar energy and ambient temperature, the thermal efficiency of the system consisting of the FPSCs and VTSCs and thus the power production efficiency of ORC increased. Thanks to these increases, hydrogen production has also increased significantly. Thus, in July, the maximum thermal efficiency of VTSCs and FPSCs was found as 6.25% and 5.46%, respectively. [ABSTRACT FROM AUTHOR]

In this study, it is aimed to compare the accounting practices of solar energy and electricity generating enterprises within the framework of uniform accounting plan and accounting standards and aim to explain the points to be considered. In the renewable energy sector, the points and the reasons for the accounting practices of the facilities are explained, accounting standards and tax legislation differences are mentioned. The research and development expenditures, license fees, value-added expenditures (special cost values), borrowing costs, deferred taxes and revenues of the rented immovable were addressed and the differences determined during the accounting stage were explained with the help of applications. [ABSTRACT FROM AUTHOR]

With today's rapid population growth and industrialization, energy needs are increasing day by day. Much of this energy needs come from fossil sources such as oil and coal. There is increasing interest in renewable energy sources in order to meet both the increasing energy demand and the fossil resources. Solar energy from renewable energy sources is one of the most important alternative energy sources for the future. In this study, the model of Organic Rankine Cycle (ORC) with parabolic solar collector assumed to be established in Isparta province and the thermodynamic analysis of the system are done. First and second law analyzes of the cogeneration system were performed and energy and exergy yields were calculated. The electricity needs of the house were met by converting to ORC with mechanical collecting using parabolic solar collectors. Then the driver includes the heating requirement of the house for the discharge of the condenser from the container. Thus, damage caused by fossil resources will be prevented and fuel saving will be ensured [ABSTRACT FROM AUTHOR]

In Turkey at the location where solar energy is rich, liquid-glazed type flat plate solar collectors have been widely used to obtain domestic hot water for many years. However, it is generally faced some products which do not fulfill the requirements of tbe final consumers and have low thermal efficiencies since this type of collectors are easily manufactured. In order to prevent from this issue, it is needed to do thermal performance tests of the solar collectors. The thermal performance tests are performed under the steady state and dynamic operating conditions. In this study, thermal performance of a liquid based (water), glazed (glass) type solar collector is determined under the dynamic operating conditions. For this purpose, thermal equation of the collector is developed, and an experimental setup is installed. Experiments are performed for four different inlet temperatures (25 oC, 30 oC, 45 oC, 60 oC) and constant mass flow rate (0.037 kg/s) at outdoor conditions. Constants in the equation are solved by Multiple Regression (MLR) method. Results of the experimental study and thermal equation show that a fairly similar characterization is obtained. [ABSTRACT FROM AUTHOR]

As the labour costs increases both in our country and in the world, pesticides are highly preferred within the scope of fight against diseases and pests in agriculture because of their ease-of-use and effectiveness. However, it is observed that pesticides are frequently and incorrectly used during the process of their applications. Consequently, human and animal health have been threatened, the causes of diseases gain resistance against the pesticide used over time, non-target organisms have been damaged, biological diversity has been reduced and phytotoxicities start to appear in culture plants. For all these reasons, the use of more reliable and cheaper solar energy methods have been are studied. In this study, the possibilities to make use of solar energy in soil disinfection in Tekirdag situated in the Thrace Region were investigated. It was calculated that water temperature could be increased to 62 °C with the use of solar connector according to the calculations made for June, July and August under the climatic conditions of Tekirdağ. The temperature of the collector water varied between 76 °C and 94 °C in the measurements performed on the solar collector in the same month due to exterior temperature. The highest temperature required for soil disinfection is 82 °C. These results obtained from the study revealed that hotbed soil could be disinfected with the thermal energy obtained from the solar collector. If the use of solar collector systems in soil disinfection is extended, it will make significant contributions to the sustainability of plant production and environmental protection. [ABSTRACT FROM AUTHOR]

The supply voltage levels of the multilevel inverters (MLIs) that are widely used nowadays are the significant limiting parameters. The major drawbacks of conventional two-level inverters used in the high power systems are the insufficient switch power against the power range, non-sinusoidal output waveforms, and increasing line transformer requirements. Furthermore, the higher switching frequency requirement to reduce the total harmonic distortion (THD) increases the switching losses. This study presents the design and analysis of a controller that is performed by using Matlab/Simulink environment. The asymmetrical MLI topology is constituted in trinary DC supply structure, and the switching frequencies are generated in sinusoidal pulse width modulation (SPWM) scheme. The grid connection of the inverter is controlled by the implemented proportional-integral (PI) controller and phase locked loop (PLL) control algorithm. The proposed control method is compared to conventional controllers in terms of THD rates and observer structure. It is observed that the designed PI controller decreases the THD ratio, with higher dynamic response. The improved control mechanism is tested under open-loop, PI controlled, and PI-PLL controlled structures to determine the THD ratios where the proposed single phase grid-tied control method is verified. The performed analysis results have shown that the PI and PI-PLL controllers provide almost same result, but the PI-PLL controller draws faster dynamic response comparing to PI control algorithm. Besides, the proposed PLL controller ensures the grid connection of inverter without complex control methods or complex algorithm requirement. [ABSTRACT FROM AUTHOR]