Modelization equations of six approaches for tracking the sun are recalled and used to evaluate the constraints and performances to which they lead to.The geographical study case is taken for the specific latitude of ...Modelization equations of six approaches for tracking the sun are recalled and used to evaluate the constraints and performances to which they lead to.The geographical study case is taken for the specific latitude of 12 North that is a good matching with the location of the country of Burkina Faso.Three decisive periods were locally established in order to consider the different travels of the sun on sky during one year.This work presents some technical data which facilitates the choice of sun tracking approaches with concern of a concentrator limits such as its angle of acceptance,its motion control card interpolation model,or its minimum irradiation level for energy conversion effectiveness.展开更多
Current PV cells technology takes advantage mainly from beam radiation. In this context the sun-trackers are such devices for efficiency improvement. On the other hand, projected shadows between devices make mandatory...Current PV cells technology takes advantage mainly from beam radiation. In this context the sun-trackers are such devices for efficiency improvement. On the other hand, projected shadows between devices make mandatory to increase the distances between mounting systems. Thus, the land’s capacity for mounting PV panels can be dramatically decreased. This fact conducts us to wonder where the optimum efficient point is. First, in this paper different types of sun-tracking systems are classified according to the movement they perform (cinematic classification). Further, three real PV installations-fixed, horizontal-axis tracking and dual-axis mount tracking—located in the same geographical area in Spain (they are approximately under the same weather conditions) are analyzed. These installations have been studied in order to establish which one is the most efficient and affordable—Specific Energy Production (SEP) and Performance Ratio (PR) analysis. PVGIS solar radiation estimate tool has been used for comparing the theoretical radiation potential on each plant. The land requirements have been considered in the analysis of the Ground Cover Ratio (GCR) and the Surface Performance Ratio (SPR). Moreover, comparing three main financial indicators let us carry out a financial study: Payback Time (PBT), Net Present Value (NPV) and Internal Rate of Return (IRR). In the case study, final annual energetic results demonstrate that the dual-axis plant shows a relevant SEP advantage, but if we take into account the land occupied for this sort of devices we find much more profitable the horizontal-axis sun-tracking system, with a SPR value 4.24% higher than the fixed system we have studied. Its PBT is also a 22% lower than the dual-axis tracking installation.展开更多
This work proposes a new design and architecture of a flexible biaxial solar tracker. A new approach was adopted with the use of a two separated cards, the smart and power card in a scalable concept. This module allow...This work proposes a new design and architecture of a flexible biaxial solar tracker. A new approach was adopted with the use of a two separated cards, the smart and power card in a scalable concept. This module allows a more saving of energy in comparison with the fixed systems for PV （photovoltaic） application and allows hire performances for CSP （concentrated solar power） systems. It provides a significant added value for higher power applications in comparison with the existing system. The developed sun tracking system is autonomous, flexible, scalable and low cost system.展开更多
The use of renewable energy resources to produce the electricity is a rising trend in various countries worldwide. This is especially because these energies do not produce the greenhouse gases;therefore, don’t become...The use of renewable energy resources to produce the electricity is a rising trend in various countries worldwide. This is especially because these energies do not produce the greenhouse gases;therefore, don’t become a destructive factor on the ozone layer and the environment. Besides, the fossil energies are always exposed to price changes and will eventually end, while the renewable energies don’t pose such problems and are freely acquired from the nature. Some of the most important of these reproducible energy resources are the energies of the wind and the solar energy. The generation capability of a photovoltaic power plant is largely dependent on the intensity of the sun radiation. On the other hand, the changing of position causes the sun to have a variable shining intensity in different seasons and different times of the year;therefore, some of the solar power plants possess solar tacking systems. This paper studies the different types of photovoltaic systems including fixed panel, photovoltaic farms equipped to the single axis and double axis tracking systems and their effects on the performance of the solar power plants. In order to determine the position of the sun in the sky, the zenith and azimuth angles of it are used to extract the relations between the different parameters of the sun radiation. The resulted parameters are used in the modeling of the single axis and double axis systems. In the paper it is utilized from the sun parameters in Qeshm Island of Iran in the summer of 2011.展开更多
The Beijing 325-m Meteorological Tower (325MT) is used to observe the vertical variation of solar radiation. Results of the experiments indicate that the automatic radiation monitoring system, including a sun tracker ...The Beijing 325-m Meteorological Tower (325MT) is used to observe the vertical variation of solar radiation. Results of the experiments indicate that the automatic radiation monitoring system, including a sun tracker and data collection system, works well and all the specifications meet WMO observation standards. The measurement data show that there is a significant radiation decrease from 320 m to the surface, where the difference is only about 30 W m-2 on light air-pollution days, while the maximum reaches about 110 W m-2 when heavy pollution appears near the ground. The global UV radiation decreases on heavy air-pollution days and under poor visibility conditions, and the difference between 300 m and 8 m is larger than on clear days.展开更多
文摘Modelization equations of six approaches for tracking the sun are recalled and used to evaluate the constraints and performances to which they lead to.The geographical study case is taken for the specific latitude of 12 North that is a good matching with the location of the country of Burkina Faso.Three decisive periods were locally established in order to consider the different travels of the sun on sky during one year.This work presents some technical data which facilitates the choice of sun tracking approaches with concern of a concentrator limits such as its angle of acceptance,its motion control card interpolation model,or its minimum irradiation level for energy conversion effectiveness.
文摘Current PV cells technology takes advantage mainly from beam radiation. In this context the sun-trackers are such devices for efficiency improvement. On the other hand, projected shadows between devices make mandatory to increase the distances between mounting systems. Thus, the land’s capacity for mounting PV panels can be dramatically decreased. This fact conducts us to wonder where the optimum efficient point is. First, in this paper different types of sun-tracking systems are classified according to the movement they perform (cinematic classification). Further, three real PV installations-fixed, horizontal-axis tracking and dual-axis mount tracking—located in the same geographical area in Spain (they are approximately under the same weather conditions) are analyzed. These installations have been studied in order to establish which one is the most efficient and affordable—Specific Energy Production (SEP) and Performance Ratio (PR) analysis. PVGIS solar radiation estimate tool has been used for comparing the theoretical radiation potential on each plant. The land requirements have been considered in the analysis of the Ground Cover Ratio (GCR) and the Surface Performance Ratio (SPR). Moreover, comparing three main financial indicators let us carry out a financial study: Payback Time (PBT), Net Present Value (NPV) and Internal Rate of Return (IRR). In the case study, final annual energetic results demonstrate that the dual-axis plant shows a relevant SEP advantage, but if we take into account the land occupied for this sort of devices we find much more profitable the horizontal-axis sun-tracking system, with a SPR value 4.24% higher than the fixed system we have studied. Its PBT is also a 22% lower than the dual-axis tracking installation.
文摘This work proposes a new design and architecture of a flexible biaxial solar tracker. A new approach was adopted with the use of a two separated cards, the smart and power card in a scalable concept. This module allows a more saving of energy in comparison with the fixed systems for PV （photovoltaic） application and allows hire performances for CSP （concentrated solar power） systems. It provides a significant added value for higher power applications in comparison with the existing system. The developed sun tracking system is autonomous, flexible, scalable and low cost system.
文摘The use of renewable energy resources to produce the electricity is a rising trend in various countries worldwide. This is especially because these energies do not produce the greenhouse gases;therefore, don’t become a destructive factor on the ozone layer and the environment. Besides, the fossil energies are always exposed to price changes and will eventually end, while the renewable energies don’t pose such problems and are freely acquired from the nature. Some of the most important of these reproducible energy resources are the energies of the wind and the solar energy. The generation capability of a photovoltaic power plant is largely dependent on the intensity of the sun radiation. On the other hand, the changing of position causes the sun to have a variable shining intensity in different seasons and different times of the year;therefore, some of the solar power plants possess solar tacking systems. This paper studies the different types of photovoltaic systems including fixed panel, photovoltaic farms equipped to the single axis and double axis tracking systems and their effects on the performance of the solar power plants. In order to determine the position of the sun in the sky, the zenith and azimuth angles of it are used to extract the relations between the different parameters of the sun radiation. The resulted parameters are used in the modeling of the single axis and double axis systems. In the paper it is utilized from the sun parameters in Qeshm Island of Iran in the summer of 2011.
文摘The Beijing 325-m Meteorological Tower (325MT) is used to observe the vertical variation of solar radiation. Results of the experiments indicate that the automatic radiation monitoring system, including a sun tracker and data collection system, works well and all the specifications meet WMO observation standards. The measurement data show that there is a significant radiation decrease from 320 m to the surface, where the difference is only about 30 W m-2 on light air-pollution days, while the maximum reaches about 110 W m-2 when heavy pollution appears near the ground. The global UV radiation decreases on heavy air-pollution days and under poor visibility conditions, and the difference between 300 m and 8 m is larger than on clear days.
