Showing papers in "Applied Solar Energy in 2019"
TL;DR: In this paper, the authors describe methods to develop the use of the renewable energy sources, particularly solar energy, and consider the key mechanisms to stimulate accelerated development of renewable energy source, using the Republic of Uzbekistan as an example.
Abstract: This paper describes methods to develop the use of the renewable energy sources, particularly solar energy. It considers the key mechanisms to stimulate accelerated development of renewable energy sources, using the Republic of Uzbekistan as an example.
20 citations
TL;DR: In this article, the design aspects and performance of a rooftop grid-connected solar photovoltaic power plant (RTGCSPVPP) has been studied for supplying the energy to whole hospital building.
Abstract: In this paper design aspects and performance of a rooftop grid-connected solar photovoltaic power plant (RTGCSPVPP) has been studied. The RTGCSPVPP is installed at Gauri Maternity Home Ramkrishna Puram Kota Rajasthan, India for supplying the energy to whole hospital building. It was observed under a certain period of time during May 2017. Power output and other parameters such as economic parameters which affect the feasibility of a PV plant as payback period, net present value, life cycle conversion efficiency, environmental related parameters as CO2 mitigation and earned carbon credits were calculated. Total energy demand and monthly energy consumption of previous one year of the site was assessed and analyzed for base load calculation and design. The outcome shows the financial viability and possible reduction of burden on conventional energy sources. The grid-connectivity of PV plant made through a net-metering system which supplied energy to the grid when power generation is more than its demand and receives the energy during low power generation.
18 citations
TL;DR: A cuckoo search (CS) algorithm to catch the global maximum power point of PV under PSC is presented and prominent outcomes show that the CS has the best performance compared to the Perturb and observe (P&O) techniques.
Abstract: A maximum power point tracking (MPPT) is a method to extract the optimal operating point of the photovoltaic power generation system. Under partial shading conditions (PSC), the power voltage characteristics exhibit more than one local peaks and one global peak. This paper presents a cuckoo search (CS) algorithm to catch the global maximum power point of PV under PSC. The main contributions of this work are to minimize the tracking time and increase the tracking efficiency of the PV modules. Furthermore, this work aims to study the behavior performance of two MPPT techniques which have been designed for extracting the GMPP under the PSC. The developed algorithms are implemented in MATLAB/Simulink platform, and their performances are evaluated. In addition, a step up (boost) DC–DC converter is designed and interfaced with resistive load in the proposed model. The prominent outcomes show that the CS has the best performance compared to the Perturb and observe (P&O) techniques. In addition, for all test cases, the tracking efficiency of the CS is higher than 99.97% within 150–180 ms.
16 citations
TL;DR: In this article, the authors presented the results of a study of wind speed and wind energy potential in Bukhara oblast located in southwestern Uzbekistan, and the main parameters k and c of the Weibull distribution function were determined using the empirical method.
Abstract: With the development of small business in Uzbekistan’s rural areas, there is a shortage of electric power, as well as power outages for these consumers. The use of renewable energy sources is one way to solve this problem, and this has been little studied in Bukhara oblast. A preliminary study of this problem shows that the region has the necessary capacity of renewable energy sources. This paper presents the results of a study of wind speed and wind energy potential in Bukhara oblast located in southwestern Uzbekistan. The data of wind speed and direction measured at the weather station at Bukhara’s international airport, taken at an altitude of 10 meters, were analyzed on the basis of the two-parameter Weibull distribution function. The main parameters k and c of the Weibull distribution function were determined using the empirical method. Wind speed and direction were statistically analyzed in MatLab and a graph (wind rose) was plotted. Wind energy potentials at different altitudes were also evaluated.
16 citations
TL;DR: In this paper, the authors study the situation on the global solar energy market and the features of designing and planning power plants based on variable renewable energy, and provide a SWOT analysis and conditions for including renewable energy into the fuel and energy balance of the republic, and also factors affecting the widespread adoption of renewable energy technologies.
Abstract: The article is a study of the situation on the global solar energy market and the features of designing and planning power plants based on variable renewable energy, and provides a SWOT analysis and conditions for including renewable energy into the fuel and energy balance of the republic, and also factors affecting the widespread adoption of renewable energy technologies. In addition, the scenario and model of developing renewable energy in Uzbekistan are suggested.
14 citations
TL;DR: In this paper, the authors present a brief analysis of the photovoltaic (PV) modules that are currently commercially available, including the possible causes of power losses of solar cells and modules, including losses caused by design features.
Abstract: This paper presents a brief analysis of the photovoltaic (PV) modules that are currently commercially available. The most used calculation formulas and measurement procedures used for evaluating the power characteristics of photovoltaic PV modules are given. The possible causes of power losses of solar cells and modules are described, including losses caused by design features. The theoretical calculations and experimental results of measuring the characteristics of silicon PV arrays with changing surface irradiance are compared. The calculated and experimental dependences of the power output variation of the ISM-50 photovoltaic module with changing its tilt angle are presented. It is shown that there is a significant discrepancy between theoretical studies and experimental results. A hypothesis has been put forward about the dependence of a real decrease in power characteristics and refraction indices of PV array protective coatings. An adjustment factor is proposed taking into account the decrease in the solar radiation output on the silicon photocell surface when passing through the antireflective protective coatings of the PV module. The conclusions drawn from the results of this work indicate that the identified factors affecting the electricity generation by photovoltaic converters need to be considered.
13 citations
TL;DR: In this article, an increase in the solar radiation flux on the receiving surface of flat-plate solar power plants by optimizing its orientation relative to the horizon was studied, and the optimal unregulated angle of the surface relative to horizon is 40°-45°.
Abstract: One of the main problems in solar power plants design is determining the optimal parameters of photovoltaic modules and auxiliary equipment (backup energy sources) that make it possible to economically justify electrical energy generation. Increasing the solar radiation utilization efficiency of the receiving surface by optimally orienting it relative to the horizon allows one to increase its performance without making changes to the design and equipment of the solar power plant. The subject of this study is an increase in the solar radiation flux on the receiving surface of flat-plate solar power plants by optimizing its orientation relative to the horizon. For the entire territory of Kamchatka krai, according to the available actinometric data on the solar radiation intensity, the optimal unregulated angle of the receiving surface relative to the horizon is 40°–45°. With transition from the south to the north of the region, the radiation intensity drops from 1395.4 kW h/m2 for Petropavlovsk-Kamchatsky to 1206.6 kW h/m2 for Korf. The optimal angle also lies within 75°–80° for winter, 15° for summer, 35°–40° in spring, and 60° in autumn. The use of seasonal adjustment leads to an increase in the solar radiation density on the receiving surfaces of flat-plate solar plants by 50 kW h/m2. Thus, increasing insolation on the surface of flat-plate solar power plants by optimally orienting it relative to the horizon allows one to increase its performance without making changes to the design and equipment of the solar power plant.
13 citations
TL;DR: In this paper, the authors analyzed the feasibility of installing a 300kW grid-connected solar photovoltaic (PV) plant in Syria, where Umm Al-Zaytun village in As-Suwayda province was chosen as a location of the plant, because it is characterized by high annual solar irradiance on the horizontal surface of about 1900 kW h/m2.
Abstract: The main objective of this paper is to analyze the techno-economic feasibility of installing a 300 kW grid-connected solar photovoltaic (PV) plant in Syria. Umm Al-Zaytun village in As-Suwayda province was chosen as a location of the plant, because it is characterized by the high annual solar irradiance on the horizontal surface of about 1900 kW h/m2. Technical performance analysis, system configuration, detailed losses and energy yield simulation for a proposed PV plant were performed, using the PVsyst software. The simulation results show, that the annual optimal tilt angle of PV modules is 25°, energy production is 493 MWh/yr, the annual average performance ratio is 0.799 and the capacity factor is 18.7%. In addition, by considering, that the electric power consumption per capita in Syria is 2232 kW h/yr, so the proposed solar power plant with 493 MW h/yr can provide energy to 220 capita/yr and save about 42.4 tons of oil equivalent yearly with carbon emission reduction of about 320.45 tCO2/yr. The economic evaluation of the proposed PV plant was carried out by Excel software with consideration, that the discount rate is 9%, the lifetime of the project is 25 years and the selling price of electricity to Syrian electricity distribution establishment is 0.119 $/kW h. The results of economic calculations show, that levelized cost of electricity is 0.094 $/kW h, the discounted payback period is about 11 years, the internal rate of return is 14%, profitability index is 1.46 and the net present value is 190587.3 $. As a result, the proposed grid-connected PV solar plant is considered economically, technically and environmentally feasible in Syria.
12 citations
TL;DR: In this article, the authors provided information on the worldwide development of decentralized energy systems which are created on the basis of utilizing, distributing and storing renewable energy, using smart control systems, about energy storage in various energy storage systems including pumped storage power plants considered one of the most efficient energy storage units.
Abstract: The article provides information on the worldwide development of decentralized energy systems which are created on the basis of utilizing, distributing and storing renewable energy, using smart control systems, about energy storage in various energy storage systems, including pumped storage power plants considered one of the most efficient energy storage units. The map of a decentralized power system, based on a wind energy, a photovoltaic, and a pumped storage plant (PSP) is proposed; the methods of making estimates to determine its parameters are given. The article also provides the results of simplified estimates made to determine the main parameters of a 5 MW decentralized power system based on a wind power and a PSP, which prove the feasibility and efficiency of the proposed map.
11 citations
TL;DR: In this article, the main reserves for increasing the efficiency of solar energy utilization in heat supply systems are considered, and the main ways of implementing the assigned task are revealed, which are: decreasing the heating temperature of heat carrier in the solar collector by 5−10°C, due to exclusion of the intermediate heat exchanger between the solar collectors and accumulator and replacement of a multi-contour system with antifreeze to a single-component self-draining unit; increasing the energy efficiency of known selfdraining plants up to 65−80% by mutual transformation
Abstract: The main reserves for increasing the efficiency of solar energy utilization in heat supply systems are considered in this paper. This is of particular relevance under the conditions of market stagnation of modern solar collectors with parameters close to their limiting values, and forcing out traditional solar water heating plants with photovoltaic systems, whose cost becomes commensurate with thermal ones. The research objective is revealing and estimating the main reserves and determining promising directions and rational ways of improving the efficiency of the solar heat supply systems, based on minimizing the loss of temperature voltage during the transfer of thermal energy from solar collector to heat accumulator and further to consumer. It is shown that the main reserves of improvement of efficiency of solar heat supply systems is the improvement of their schematics, auxiliary equipment and operating parameters using the simplest self-regulating active elements, that can significantly influence the hydrodynamics of non-isothermal fluid flow in the system and its thermal efficiency when low specific flow rates of heat carrier through solar collector. The main ways of implementing the assigned task are revealed, which are: decreasing the heating temperature of heat carrier in the solar collector by 5–10°C, due to exclusion of the intermediate heat exchanger between the solar collector and accumulator and replacement of a multi-contour system with antifreeze to a single-contour self-draining unit; increasing the energy efficiency of known self-draining plants up to 65–80% by mutual transformation of potential and kinetic energy of a fluid in the Venturi tube and thereby eliminating the loss of hydrostatic pressure due to jet rupture; decreasing the temperature difference by 5—10°С when charging and discharging the heat accumulator using high-efficient temperature stratification of water; reducing the loss of temperature voltage and stabilization of water heating temperature in thermosiphon solar hot water supply systems due to its single heating in solar collectors; reducing the average operating temperature by 5–10°C of the solar collector and of the helio field of solar collectors by increasing the uniformity of fluid flow distribution by individual collector channels and the helio field as a whole.
10 citations
TL;DR: In this paper, the operation principle of vanadium redox batteries, which is based on redox processes that occur in two volumes with vanadium electrolytes separated by a selective membrane, has been considered.
Abstract: Modern storage systems for electric energy generated by solar photovoltaic plants and other renewable energy sources have been analyzed. Among numerous energy storage systems, electrochemical ones, particularly redox battery systems, are of the greatest interest for use in the Central Asia region. The varieties of this energy storage system have been considered, including Zn/Br, Zn/Cl, Fe/Cr, Zn/Se, and Zn/K3Fe(CN)6 systems, as well as promising but underdeveloped iron–iron and lead hybrid operating on electrolytes based on sulfuric acid and with deposition on bipolar electrodes (Pb) and (PbO2), respectively. We have considered the operation principle of vanadium redox batteries, which is based on redox processes that occur in two volumes with vanadium electrolytes separated by a selective membrane. Their advantages for the above goals have been demonstrated. We discuss the prospect of vanadium redox battery production in Uzbekistan based on local vanadium resources in the form of both primary mined materials and manmade raw materials, such as vanadium-containing slags resulting from extraction during metallurgical processing of mined titanium and rare-earth element ores, as well as those formed during the processing of bauxite and phosphorite mined in local deposits. Particular emphasis has been placed on the question of combining the use of domestically produced vanadium pentoxide with developments of electrode surface activation for redox batteries made from graphitized materials with the inclusion of nanoscale particles of metals, such as iron and nickel, using ion-plasma technologies.
TL;DR: In this article, an autonomous device for water purification in remote rural areas of the Republic of Uzbekistan has been developed using an ultraviolet lamp with electricity supply from photovoltaic systems.
Abstract: The Republic of Uzbekistan currently has an urgent need to provide drinking water to the population of remote rural areas. The water sources in these areas are usually heavily polluted by pathogenic bacteria and the water must be sterilized before use. Due to the remote nature of settlements in these areas, it is impossible to perform this task using traditional methods suitable for urban areas, due to economic challenges. The problem is the lack of a developed infrastructure (electricity, communications) because of the economic situation and the remote location of these villages. In view of this, the scale of infectious diseases of people caused by poor-quality water in rural areas of the republic is quite high. In this regard, the development of compact and efficient water purification devices, which should be affordable for the rural population, is of particular relevance. Unlike most disinfectants, ultraviolet (UV) radiation does not inactivate microorganisms by chemical interaction. UV irradiation inactivates organisms by absorbing light, which causes a photochemical reaction that changes the molecular basis of the components to the function of the cell. As UV rays penetrate the cell wall of a microorganism, energy reacts with nucleic acids and its other vital components, leading to the injury or death of exposed cells. Ultraviolet lamps work in almost the same way as fluorescent lamps. The difference between the two lamps is that the fluorescent bulb of the lamp is coated with a phosphorous compound that converts ultraviolet radiation into visible light. The UV lamp is not covered, so it transmits the ultraviolet radiation produced by the arc. This study confirms the efficiency of the developed scheme of an autonomous device for disinfecting water when it is exposed by the radiation of an ultraviolet lamp with electricity supply from photovoltaic systems.
TL;DR: In this article, a pendulum-type converter is proposed for sea wave energy conversion and shown that the efficiency increases significantly if a low-damped mechanical oscillator which is adapted to a wave power spectrum, is used as a primary converter.
Abstract: This paper is concerned with the issue of the efficiency of sea wave energy conversion. It is shown that the efficiency increases significantly if a low-damped mechanical oscillator, which is adapted to a wave power spectrum, is used as a primary converter. Two major types of oscillators are considered. The pendulum-type converter is found to be the most promising. A new schematic of a pendulum-type converter is suggested and briefly described. The converter consists of two oscillators adjusted to work in resonance mode. The first one includes a ballast-controlled floating platform pitching on sea waves. The second oscillator is a long sector-shaped pendulum located on the floating platform. The use of sea wave energy converters is promising in regard to the widespread use of renewable sources and elimination of the environmental impact of fossil fuel consumption in coastal regions. Various systems have been developed and projects implemented in this field.
TL;DR: In this article, the authors present an ATmega 328p microcontroller, which transfers processed data from the sensors to the server by sending a GET request using a W5100 Wiznet Ethernet controller.
Abstract: The need for application of a device for online remote monitoring of electrical parameters and the operability of photovoltaic converters of solar power plants is justified in the context of the problems encountered in the Sevastopol Solar Power Plant (S. Energy Sevastopol LLC) operation. A structural diagram of the device showing the connection and purpose of its main functional components is presented. The circuit is based on an ATmega 328p microcontroller, which transfers processed data from the sensors to the server by sending a GET request using a W5100 Wiznet Ethernet controller. Such a solution allows for a high data transfer rate—up to 25 Mbps—and provides a simple connection to the Internet independently from operating systems and external computers. The characteristics and performance analysis of galvanically isolated sensors used in the device are presented, such as a current sensor based on an Allegro ACS712 integrated current sensor, and a voltage sensor based on the transistor optocoupler. The results of the device operation illustrating the photovoltaic plant daily operation on a sunny fall day are provided. The device provides for continuous monitoring of the operation of the photovoltaic converters with long-term storage of measured values in graphical and numerical form, which makes it possible for operational and dispatching personnel to visually analyze the plant operation, monitor its performance, compare key performance indicators of various sections, and obtain production reports by periods with plotting of curves, as well as receive alarm signals.
TL;DR: In this article, the authors discussed the use of hybrid predicting methods that imply taking into account the possibility of the weather scenarios simulation, advanced cloud-based image processing technology, and close-to-real-time cloud motion surveillance cameras.
Abstract: The construction and operation of large solar power plants (SPPs) and the dependence of their production on light and other meteorological factors leads to a strong dependence of the operation modes of the Republic of Crimea and Sevastopol power system on meteorological factors. Today, given that the share of solar power plants is about 30% of the total installed capacity, it is necessary to solve the problems that have a great impact on the power system operating modes. With large output capacity of the solar power plant, the operator has to give commands to turn off the generating equipment of thermal power plants. In power systems with a large share of solar generation, it is necessary to solve this problem by improving the generated power predicting methods, as it will reduce the dependence of operating modes on weather factors and increase the reliability of the power system. The paper discusses the use of hybrid predicting methods that imply taking into account the possibility of the weather scenarios simulation, advanced cloud-based image processing technology, and close-to-real-time cloud motion surveillance cameras. There was an experimental software created that selects coefficients of set configuration time series. In combination with the conservative methods, it makes predicting the SPP Perovo output more accurate. Taken together, the chosen methods of predicting solar power generation capacity in the power system of the Republic of Crimea and Sevastopol ensure not only stability of the power system as a whole, but also the maximum efficiency of power plants, allow to accelerate the integration of solar power plants into the power system, and have positive effects on the environment.
TL;DR: In this article, a new schematic of a desalination complex based on wind energy marine units is proposed, and the key parameters of the complex are determined based on an analysis of the water shortage in northern Crimea.
Abstract: This paper is concerned with the problem of water shortage in northern Crimea. It shows that the Crimean Peninsula lacks access to fresh water from natural sources. For decades, water supply was provided mostly from the Dnieper River via the North Crimean Canal. An emergency situation arose in water supply in Crimea after the canal was shut down. It has been shown that seawater desalination from renewables is the only reliable way to tackle the problem. The work reviews perspective desalination methods, suggests a new schematic of a desalination complex based on Wind Energy Marine Units, and determines key parameters of the complex.
TL;DR: In this paper, a low power consumption sun tracking system has been implemented for driving a crystalline silicon photovoltaic module under variable weather conditions, and the experimental results showed that this sun follower consumes less than 1% of the increased energy.
Abstract: Sun tracking systems are often used to improve the performance of crystalline silicon photovoltaic plants. However, their power consumption still remains a challenge till date. In this paper, a low power consumption sun tracking system has been implemented for driving a crystalline silicon photovoltaic module under variable weather conditions. The experimental results showed that this sun follower consumes less than 1% of the increased energy. Taking into account the tracker consumption, the energy gain can attain up to 25% under the same weather conditions compared to a fixed photovoltaic system. In addition to that, results gotten from data-based simulations are coherent with experimental results.
TL;DR: In this paper, the progress of work on the revising of building codes and regulations of the "Solar Hot Water Installations" operating in the territory of the Republic of Uzbekistan is shown.
Abstract: The progress of work on the revising of building codes and regulations of the “Solar Hot Water Installations”, operating in the territory of the Republic of Uzbekistan is shown. The goal of the work is to create a modified republican regulatory document that meets modern requirements and provides an increase in the energy efficiency of designed solar hot water installations by 30%. The analysis was conducted with domestic and foreign experience in the design, and construction and operation of solar hot water installations for various purposes was studied and summarized. The selection of advanced technical achievements and scientific research of different countries in the field of energy saving and efficient use of solar energy has been carried out. In the process of revising the regulatory document, outdated regulations were excluded; new regulatory requirements were included, taking into account the current level of scientific and technological achievements, design and construction practices, and regional features of the Republic of Uzbekistan. The article introduces and substantiates main changes made to the previously existing building codes and rules, developed on the basis of the analysis of generally accepted results of completed research, development and experimental work, the study and synthesis of domestic and foreign experience in designing, building and operating solar hot water installations for various purposes.
TL;DR: For various Russian Federation regions that are neither close to the generating facilities nor have reliable uninterrupted electricity supply, the presented system can significantly extend both the time of efficient use of energy resources and the service life of the equipment.
Abstract: Power supply to consumers, especially in remote areas, is often subject to emergency power outages. This leads to numerous problems such as the breakdown of household appliances and electronics, the inability to provide vital functions in homes and special institutions, and production failure. Also, grid companies sometimes cannot efficiently provide energy to private consumers due to insufficient capacity of the power grid. This journal discusses the use of power plants on alternative energy sources and systems of accumulation of electric energy connected to renewable energy sources. Such systems can be used in parallel with the existing electric power grid, as well as directly by autonomous consumers. This journal also describes the possibility of providing electric power to individual consumers using solar panels in combination with a system of accumulator batteries. The process of charge–discharge of capacitive batteries in the photovoltaic module–battery system is studied in order to increase the efficiency of low-power autonomous power plants. Studies show an increase in the efficiency of the system designed for the individual consumer by 30%, as well as the possibility of uninterrupted operation. The proposed model of the combined photovoltaic and storage system avoids the problems associated with emergency power outages. More importantly, for various Russian Federation regions that are neither close to the generating facilities nor have reliable uninterrupted electricity supply, the presented system can significantly extend both the time of efficient use of energy resources and the service life of the equipment.
TL;DR: In this article, a model sufficient to predict in different contexts of global solar radiation on a horizontal plane and other inclined area was proposed. And the experimental results show, that the values obtained, give a good estimate of the solar radiation and are in good agreement with those given by the elaborate model, which is in agreement with that of Perrin de Brichambaut, also more particularly for an incident on an inclined area.
Abstract: This work is done to propose a model sufficient to predict in different contexts of global solar radiation on a horizontal plane and other inclined area. This is very important for a variety of applications of solar energy conversion. Indeed, the lack of data before, we will not know what will be the solar potential before to ensure such feasibility or function. After this study, the development of a suitable model for the Biskra site for five angles of inclination, of any solar project was made through an experimental study. The experimental results show, that the values obtained, give a good estimate of the solar radiation and are in good agreement with those given by the elaborate model, which is in agreement with that of Perrin de Brichambaut, also more particularly for an incident on an inclined area.
TL;DR: In this article, the authors considered the structure of the regional energy supply of Crimea and presented the characteristics of the main groups of regional electricity producers, including combined heat and power plants, mobile gas turbine power plants and renewable energy sources, and backup power sources.
Abstract: This paper considers the structure of the regional energy supply of Crimea and presents the characteristics of the main groups of regional electricity producers, including combined heat and power plants, mobile gas turbine power plants, renewable energy sources, and backup power sources. It is proposed, depending on the purpose of calculations in the context of the transportation problem under consideration, to use average actual rates for a given period with energy suppliers as tariffs (the calculation purpose is to reduce the electricity production and transportation cost), as well as conditional qualitative assessments, such as “fines” (the purpose is to improve the environmental friendliness and reliability of the system as a whole). The influence of the produced solar plant power on the operating modes of the Crimean energy system is assessed. The solar power production optimization technique that affects the reliability and quality of power supply is developed. Various energy supply scenarios for Crimea are generated, including peak and average power consumption modes with various options for solar activity, season, including and excluding energy sources under construction, and off-season repair of power sources. Based on the calculation data, the reliability of the regional energy system is estimated for various power supply scenarios, as well as the need to use an energy bridge for a power exchange with the mainland.
TL;DR: In this paper, the current status of meteorological stations of actinometric observations in Uzbekistan is compared with the satellite observations and reanalysis data from NASA POWER, ERA5, and SARAH-E.
Abstract: This work considers the current status of meteorological stations of actinometric observations in Uzbekistan. The data obtained from six modern ground-based meteorological stations in Uzbekistan are compared with the satellite observations and reanalysis data from NASA POWER, ERA5, and SARAH-E. It is shown that the comparative deviations of the data of NASA POWER from the ground monthly amounts of solar radiation on the horizontal surface for most regions of Uzbekistan from April to September do not exceed 8%, which is quite acceptable for the design of solar power plants. The comparative deviations of the data of ERA5 and SARAH1E for the same period of the year do not exceed 8 to 12%. According to the results of the calculation studies on verifying global horizontal solar radiation using the three aforementioned databases, these can be used in engineering calculations. When performing calculation studies, one can select any base depending on the required information, i.e. daily or hourly solar radiation values.
TL;DR: In this article, the results of the first stage of verification of the generalized computational algorithm for determining the geometrical, dynamical, and energy parameters of the "parabolic trough concentrator - tube heat receiver" solar receiver system were presented.
Abstract: This paper presents the results of the first stage of verification of the generalized computational algorithm for determining the geometrical, dynamical, and energy parameters of the “parabolic trough concentrator – tube heat receiver” solar receiver system. This algorithm is based on the dimensionless coupled mathematical model of heat and mass exchange in the “Sun – parabolic trough concentrator – tube receiver” system. The Monte Carlo ray tracing method was used to calculate irregular heat flux from the concentrator to the tube receiver surface. The 3D mathematical model of heat exchange in the tube receiver was solved using the finite volume method. The mathematical model took local climatic and geographical features into account, as well as micro- and macroscopic imperfections of the concentrator surface. The dimensional problem of heat exchange in the tube receiver of the solar parabolic trough system was solved at the first stage of verification. A simplified physical model was described. It was assumed that the glass envelope around the tube receiver was removed. The dimensional mathematical model of heat exchange in the tube receiver is based on the system of Navier–Stokes equations for viscous incompressible liquid with constant physical properties. The mathematical model with real boundary conditions was solved numerically. An analytical solution for the test problem with trivial boundary conditions was obtained. The results of the test numerical problem were compared with analytical solution results and were found to be in close agreement. Numerical experiments with real boundary conditions were conducted using the computational algorithm. The numerical data were compared with the results of field experimental studies and showed nearly total agreement, which proved the adequacy of the basic mathematical model and the resulting numerical algorithm.
TL;DR: In this article, the authors developed a thermodynamic model of a photovoltaic module with an asymmetric parabolic trough concentrator and a line photodetector with a triangular profile, which is supplied with the heat carrier channel system.
Abstract: In this work, the new photovoltaic modules, including the photodetectors and concentrators, providing the effective transformation of solar energy into thermal and electric energy are considered. The creation of the algorithm of the design calculation of the thermo-photo-electric module with the set power parameters with the use of laws of geometrical optics, and also heat and mass exchange are mathematically modelled. When using similar modules, at the heart of which there is a paraboloidal concentrator and a photodetector with the heat carrier’s channel system, the creation of the cogeneration installations for the development of electricity and heat is possible. In the course of the research, a solar module with a parabolic trough concentrator and a line photodetector with a triangular profile, which is supplied with the heat carrier channel system, is developed for the first time and the physical and mathematical models are developed, based on which, the following aspects are developed: the design data of the module; distribution of sunlight concentration across the width of the photodetector; dependences of the thermodynamic values of heat conductivity, the viscosity of the heat carrier (water) on temperature and their ratio from the distribution of the heating of the heat carrier across the profile of the photodetector; distribution of the temperature of the heating of the heat carrier; distribution of the heating energy of the heat carrier; the time of the heat carrier’s heating; and the heating of the heat carrier’s mass per unit of time; the thermal power of the heat carrier and the thermal efficiency of the module (coefficient of efficient use of power of solar radiation), which adequately reflect real parameters of the functioning of the manufactured SB solar modules. It is shown that the thermal efficiency (and, respectively, other power parameters) of a module with a photodetector with a triangular profile at any distribution of the illumination exceeds the thermal efficiency of a module with a photodetector with a rectangular profile. The model samples, developed by such a technique are investigated at the corresponding stands, and are tested in natural conditions. The solar module with the asymmetric parabolic trough concentrator with a line photodetector of a triangular profile of the concentrated radiation with the heat carrier channel system ensures the water heating temperature (ranging from 38 to 60°С) with the reduction of water consumption (from 11.1 to 5.5 l/h), at an illumination of ~850 W/ m2, and the thermal efficiency changes within 49–65%.
TL;DR: In this paper, the structural and morphological characteristics of antimony selenide (Sb2Se3) thin films, which were deposited by the chemical molecular beam deposition (CMBD) in atmospheric pressure hydrogen flow on an alkali glass substrate.
Abstract: This work presents the structural and morphological characteristics of antimony selenide (Sb2Se3) thin films, which were deposited by the chemical molecular beam deposition (CMBD) in atmospheric pressure hydrogen flow on an alkali glass substrate. It was found that the deposition temperature affected the morphology and structure of the films. At a low deposition temperature of 720 K, the film depicts a preferable crystal orientation (211), i.e., one-dimensional (1D) Sb2Se3 ribbons are aligned along the growth direction. Morphological studies show that the grain size increases with the temperature of the substrate; however, the 1D Sb2Se3 chains tend to align along the lateral direction. The Sb2Se3 films were found to have a preferable orientation (211) and polycrystalline structure. At higher substrate temperatures of 770 and 820 K, they also have a polycrystalline structure, but with an orientation (120). The studies of surface morphology show that at low substrate temperatures the samples have fine grains that have sizes of (200–300) nm, but are rather tightly packed and have 1D Sb2Se3 chains, which are aligned along the growth direction that corresponds to the orientation (211). It was found that the Sb2Se3 thin films with the orientation (211) were suitable for an absorber layer of solar cells, due to their anisotropic properties.
TL;DR: In this article, a two-in-one parabolic trough collectors (PTC) setup is proposed to heat water and air simultaneously, where the unused absorbed heat from the collector is used to heat the air which is passed via bottom chambers.
Abstract: Parabolic trough collectors (PTC) are solar thermal energy collectors designed to capture the sun’s direct radiation over aperture area and concentrate it onto a focal point. Parabolic shaped mirrors are used to focus the solar radiation on the pipe that carries water to heat it. The concentrated heat from the parabolic collector heats up the water and helps in producing hot water which can be used domestically. Drying is one of the important and energy consuming processes. Especially foragricultural product processing open yard drying is widely adapted, without proper hygienic condition. The presently designed cost effective two in one PTC setupcanheat water and air simultaneously. In the box shaped structure the hot water isgenerated at the top of the box. The unused absorbed heat on the collector is used to heat the air which is passed via bottom chambers. As a result, hot water (60°C) and hot air (45°C) can be obtained which is used mainly for heating purpose. Manual tracking type of design is chosen for cost effectiveness and simplicity in structure. This Combined water and air heating design improves the total efficiency of the system up to 4.3% when compared with the conventional PTC design. In addition, the emission reduction of 1 kg of CO2/day can be achieved and simple payback period is 2 years when compared to electric heaters which can be easily affordable by common man.
TL;DR: In this article, the authors presented the assessment of water resources and condition of drinking water supply in Uzbekistan and the problem of the Aral Sea, as well as resources, shortages and forecasts on fresh water resources in the world are estimated on the basis of available data.
Abstract: Data on the condition of drinking water supply in the world are provided in this work, as well as resources, shortages and forecasts on fresh water resources in the world are estimated on the basis of the available data. The assessment of water resources and condition of drinking water supply in Uzbekistan is presented and the problem of the Aral Sea is mentioned. As one of the main solutions to the problem of drinking water supply for the region’s population, the desalination of saline waters with the use of renewable energy sources (RES), generally solar energy, is proposed. Current global trends on the development of desalination installations with the use of renewable energy sources and forecasts for further development are analyzed. Taking the international experience and development into account, as well as the specifics of our region, some recommendations on the stimulation and development of use of desalination installations using renewable energy sources to improve the quality of the population’s drinking water supply, especially in remote regions, are offered.
TL;DR: In this article, the effect of cetyltrimethyl ammonium bromide (CTAB), anionic sodium dodecyl sulphate (SDS), and non ionic tween 80 surfactants on the electrical output of the cationic oxazine dye brilliant cresyl blue (BCB)-fructose (redox couple) system in photogalvanic cells have been studied.
Abstract: The photogalvanic cells are rechargeable device with the sun light in which surfactant solutions are potentially important for efficient energy conversion and storage. Here, effect of cationic cetyltrimethyl ammonium bromide (CTAB), anionic sodium dodecyl sulphate (SDS) and non ionic tween 80 surfactants on the electrical output of the cationic oxazine dye brilliant cresyl blue (BCB)-fructose (redox couple) system in photogalvanic cells have been studied. For this, the photopotential and photocurrent for different cells having BCB-fructose system without and with surfactant (CTAB, SDS and tween 80) in the alkaline medium have been measured. The total 30 different cells have been prepared for optimizing the concentration of electrolytes corresponding to the higher electrical out put. Generally, the electrical output increases in presence of a particular surfactant, due to increase in solubilization and stabilization properties of dye molecules in the water. The amount of enhancement in electrical output of BCB-fructose system was highest with SDS and lowest with tween 80, i.e. the order for BCB-fructose system with different surfactants in photogalvanic cells is: BCB-fructose-SDS > BCB-fructose-CTAB > BCB-fructose-tween 80. This order for electrical output was good agreement with the stability order of BCB-SDS/CTAB/tween 80 system, on the basis of spectrophotometric study. Hence, among these surfactants, SDS has stronger capacity, (due to opposite charge on BCB and SDS) to stabilize the BCB-fructose system leads to enhancement in electrical output of photogalvanic cells. Therefore, dye and surfactant, having chemical structure, like BCB and SDS, has a great importance of improvement of electrical performance to photogalvanic cells in the future.
TL;DR: In this article, the effect of atmospheric climatic factors on the operation of photovoltaic modules of a power plant was studied, and the modes of operation of the solar power plant were studied depending on temperature parameters, as well as taking into account the wind load and other parameters.
Abstract: This article paper the results of studying the effect of atmospheric climatic factors on the operation of the photovoltaic modules of a power plant. The modes of operation of the solar power plant were studied depending on temperature parameters, as well as taking into account the wind load and other parameters. The change in the production of electric energy is shown for various results of the study of a serial photovoltaic module RS 250 with a power of 250 W, which is used for the generation of electric energy at some solar power plants in the south of Ukraine. The results make it possible to evaluate its performance in natural conditions depending on various climatic factors. The article describes the study of the operation of a wind power plant (WPP) with helical blades; this type of WPP allows using the kinetic energy of the wind flow more fully to convert it into mechanical energy of rotation of the wind turbine shaft. The coefficient of wind energy utilization by the rotor of a wind turbine with such a design is much higher than that of horizontal-axis wind turbines. Wind–solar power plants operating in parallel with the general power grid occupy quite large territories. In this case, as a rule, wind turbines are located in the north part of the plant, without interfering with the operation of the modules, while photovoltaic modules are located on the south side of the wind turbines, which minimizes the losses from shading by the tower, engine room, and wind turbine blades. All the studies described above allow installing additional generating capacities on wind and solar power plants, which will greatly increase the total production of the plant and the efficiency of the entire energy complex.
TL;DR: In this article, a standalone cooling system is designed as prototype which helps to proposal for a methodology for large-scale application through energy estimation of this system, and the cooling system used in this study will be beneficial with using of string of PV panels with a minimum of three panels.
Abstract: The use of solar energy is very promising for favorable Sun Belt countries. However, in these regions the hot climate leads to high temperatures which conduct to significant power losses in photovoltaic panels. In this paper we study the heating behavior of photovoltaic panels and front side water cooling efficiency. A standalone cooling system is designed as prototype which helps to proposal for a methodology for large-scale application through energy estimation of this system. Two typical situations were studied: the first one with a uniform distribution of the temperature and the second one with a non-uniform distribution of temperature under partial shadowing leading to hot spot effect. The gain in electrical power with cooling is about 45% in the case of a non-uniform distribution compared to 12% in the case of a uniform distribution at 30°C outdoor temperature. It was also noticed that temperature on hot spot point depends of the shadow type (direct and indirect). The estimation of the supplement of energy obtained from the cooling system demonstrates that the cooling system used in this study will be beneficial with using of string of PV panels with a minimum of three panels. This makes the autonomous cooling system very efficient.