Vol 54, No 2 (2018)
- Year: 2018
- Articles: 12
- URL: https://journals.rcsi.science/0003-701X/issue/view/8925
Direct Conversion of Solar Energy to Electricity
Design and Optimization of Amorphous Based on Highly Efficient HIT Solar Cell
Abstract
The objective of this paper is to improve the power conversion efficiency of HIT solar cell using amorphous materials. A high efficiency amorphous material based on two dimensional heterojunction solar cell with thin intrinsic layer is designed and simulated at the research level using Synopsys/RSOFT-Solar Cell utility. The HIT structure composed of TCO/a-Si:H(p)/a-Si:H(i)/c-Si(n)/a-Si:H(i)/a-Si:H(n+)/Ag is created by using of RSOFT CAD. Optical characterization of the cell is performed by Diffract MOD model based on RCWA (rigorous coupled wave analysis) algorithm. Electrical characterization of the cell is done by Solar cell utility using based on Ideal diode method. In addition, optimization of the different layer thickness in the HIT structure is executed to improve the absorption and thereby the photocurrent density. The proposed HIT solar cell structure resulted in an open circuit voltage of 0.751 V, a short circuit current density of 36.37 mA/cm2 and fill factor of 85.37% contributing to the total power conversion efficiency of 25.91% under AM1.5G. Simulation results showed that the power conversion efficiency is improved by 1.21% as compared to the reference HIT solar cell. This improvement in high efficiency is due to reduction of resistive losses, recombination losses at the hetero junction interface between intrinsic a-Si and c-Si, and optimization of the thicknesses in a-Si and c-Si layers.
Prospects for the Production of Silicon and Solar Energy Products in the Republic of Uzbekistan
Abstract
The paper presents the results of a comparative analysis of the technical and economic parameters of the trichlorosilane and monosilane processes of silicon production. It is shown that Russia’s available gangue quartz, quartz sands, natural gas, and new methods of smelting technical silicon, as well as new technologies for its conversion into monosilane, makes it possible to organize environmentally friendly industrial production of raw silicon and competitive, highly efficient photovoltaic energy products based on monosilane technology.
Morphology and Photoelectric Characteristics of the Thin-Film Polycrystalline Structure SnO2-CdS/Cu(InGa)Se2-Ag
Abstract
The surface morphology and photoelectric characteristics of a thin-film SnO2-CdS/Cu(InGa)Se2-Ag heterostructure have been studied. The chemical and phase composition of the Cu(InGa)Se2 film in the synthesized structure have been investigated. The current transfer mechanism has been studied, and the main parameters of the semiconductor material have been determined. It has been found that there are no oppositely connected barriers in the heterostructure.
Solar Power Plants and Their Application
Calculating the Hydrodynamic Characteristics of the Active Section of the Self-Draining Solar Loop of a Heating System
Abstract
The article considers experimental studies of the hydrodynamic characteristics of the active section of the self-draining solar loop of a heating system. This element is designed as a flow constrictor referred to as Ventury tube, with a high degree of flow constriction of 2–5 in the region with strong viscous resistance. The experimental data are processed in a criteria form, the general type of which is obtained by dimensional technique and compared with data from other authors. The obtained criteria dependences can be used to calculate the hydrodynamic characteristics of the active section of the self-draining solar loop of a heating system.
Characteristic Features of the Energy Modes of a Large Solar Furnace with a Capacity of 1000 kW
Abstract
The possible energy characteristics of the LSF (large solar furnace with a capacity 1000 kW) based on numerical calculations are analyzed. The technical characteristics of the LSF are presented. The energy characteristics of the total system with different inaccuracies of the reflecting surfaces, energy contributions of certain shelves and groups of heliostats, and the contributions of certain heliostats and shapes of their focal spot are determined. Empirical formulas are proposed to describe the obtained numerical results. The problem of implementing the possible energy modes of the LSF with and/or without the inclusion of certain shelves and groups of heliostats is analyzed. The problem of a change in the energy density distribution in the focal spot of the LSF during the day is considered.
Utilizing of Solar Energy for Extracting Freshwater from Atmospheric Air
Abstract
It presents a method to extract pure water from atmospheric air, which depends on intensifying the water vapor from the air. The plant was designed to perform the optimum levels to produce high quality water with minimal electricity consumption. The harvesting water was inspected and analyzed based on ISO/IEC 17025 method to check the purity of water. This study also investigates the potential of a solar powered using for atmospheric water generation (AWG) as a new option for fresh water production. A proposed solar AWG unit was assembled, analyzed and modeled using HOMER software. The results demonstrated that the water produced by the water extraction plant is pure, safe, economical, and acceptably tasting. It can be used as drinking water after treated by filter and disinfected by Ultra Violet Light (UV) technique. The feasibility analysis showed that there is a potential to adopt solar powered of AWG as strategic and alternative option for a small area; which is suffering from a shortage of drinking water.
Study of the Thermal Technical Characteristics of a Combined Solar Desalination and Drying Plant
Abstract
The paper presents the results of calculated research on determining the thermal technical indicators of a combined solar desalinization and drying plant. The structure of the plant is developed and proposed. A mathematical model is developed that describes the thermal processes occurring in the plant based on heat-balance equations solved using the Laplace method.
Method for Increasing the Efficiency of a Biaxial Solar Tracker with Exact Solar Orientation
Abstract
Modern solar follow-up systems make it possible to increase a solar cell’s efficiency and, as a result, solar energy utilization. The paper considers modern solar follow-up methods and their operational principles. Trackers are separated onto uniaxial and biaxial according to the plane which tracking occurs. Biaxial trackers are the most efficient. The operational principles of active and passive trackers are studied. A laboratory model of a biaxial solar tracker with precise solar orientation is described, based on an algorithm for calculating the voltage with current sensors. The following are given in the paper: the current–voltage characteristic obtained for different solar array positions and using trackers; the relationships between the power and measured currents and voltages. The efficiency is calculated for different solar array positions and using a tracker.
Solar Energy Concentrators
10% Loss of Incident Power through Solar Reactor Window: Myth or Good Rule of Thumb?
Abstract
It is known that a solar beam crossing a window losses 10% of its incident power. Yet, this affirmation is not supported by many published scientific evidences. In this work, a heat flux mapping method was used to determine the heat flux distributions at the focal spot of a solar concentrating device without and with a window on the incident beams' trajectory. The presence of a window on the beams' trajectory induces a 12% loss of the total power and a 11% decrease of the peak heat flux density.
Performance of Cylindrical Parabolic Collector with Automated Tracking System
Abstract
Parabolic solar collector collects the radiant energy emitted from the sun and focuses it at a point. Parabolic trough collectors are the low cost implementation of concentrated solar power technology that focuses incident sun light on to a tube filled with a heat transfer fluid. However, the basic problem with the cylindrical parabolic collector without tracking was the solar collector does not move with the orientation of sun. Development of automatic tracking system for cylindrical parabolic collectors will increase solar collection as well as efficiency of devices. The main aim of this paper is to design, fabricate and analyze the performance of parabolic collector with automated tracking system. The automated tracking mechanism is used to receive the maximum possible energy of solar radiation as it tracks the path of sun. The performance of the parabolic trough collector is experimentally investigated with the water circulated as heat transfer fluid. The collector efficiency will be noted.
Economics and Ecology of Solar Engineering
Reducing the Costs of Paying for Consumed Electric Energy by Utilizing Solar Energy
Abstract
The use of a low-power solar network and standalone power plants is the most promising for the needs of the housing and utilities sector, small industrial enterprises, social and public health facilities, recreation areas, remote objects, and agricultural industries; this will make it possible to reduce the load on the energy system at peak moments, as well as to decrease losses when transporting electric energy in its elements. It is assumed that the minimum value of the unit cost of generated electric energy is used as the criterion for configuring and selecting the parameters of solar power equipment, which will make it possible to set up an economically feasible additional power supply to the consumer, since it excludes the use of storage devices and rearrangement of the power supply system.
Renewable Energy Sources
Artificial Continuous Air Current Generation Plant
Abstract
A plant theoretically capable of generating a 24/7 continuous induced air stream and the concept of this plant are described, as well as its operational principle and materials from which the plant will be manufactured. Arguments in favor of the relevance of this plant are adduced.