scholarly journals The Effect of Collector Shading and Masking on Optimized PV Field Designs

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3471
Author(s):  
Avi Aronescu ◽  
Joseph Appelbaum
Keyword(s):  
Energy Loss ◽  
Global Radiation ◽  
Incident Radiation ◽  
View Factor ◽  
Diffuse Component ◽  
Isotropic Model ◽  
Direct Beam ◽  
Tel Aviv ◽  
Sky View Factor ◽  
Beam Incident

Photovoltaic (PV) solar fields are deployed with multiple rows. The second and subsequent rows are subject to shading and masking by the rows in front. The direct beam incident radiation on the second row is affected by shading and the diffuse incident radiation is affected by masking, expressed by sky view factor. Hence, all rows, besides the first one, receive lower incident radiation. The design of PV fields must take into account the decrease in the incident radiation caused by these two effects. The paper investigates by simulation the annual incident diffuse, direct beam and global radiation on the first and on the second row for optimized PV fields at two sites: Tel Aviv, Israel, with low diffuse component, and Lindenberg–Germany monitoring station, with a high diffuse component. The study emphasizes the importance of the diffuse incident radiation on the energy loss of the PV field. The percentage annual global energy loss due to shading and masking on the second row amounts to 1.49% in Tel Aviv and 0.46% in Lindenberg. Isotropic and anisotropic diffuse models were considered. The calculated diffuse incident energy for the isotropic model is lower than the values for anisotropic model by about 8% in Tel Aviv and 3.75% in Lindenberg.

Experimental Verification of the Sky View Factor Model in Multiple-Row Photovoltaic Fields

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Y. Massalha ◽  
J. Appelbaum
Keyword(s):  
Experimental Study ◽  
Energy Loss ◽  
Factor Model ◽  
Diffuse Radiation ◽  
View Factor ◽  
Pv Systems ◽  
Sky View Factor ◽  
Row Width ◽  
Pv Modules ◽  
Inclination Angles

Abstract In multiple rows of photovoltaic fields, the rows may be installed with several modules placed along the row width. The verification of the sky view factor model pertains to the second and subsequent rows. Photovoltaic (PV) modules along the row width experience uneven incident diffuse radiation caused by differences in the sky view factor of the modules. The present experimental study verifies first the sky view factor model, and second shows the differences in output power of the PV modules (affected by the sky view factors) placed in different locations along the width of the second row. This work complements the theoretical previous work and emphasizes the importance of the incident diffuse radiation, associated with the sky view factor, on the energy loss of the PV field. Two rows deployed with PV modules were tested on the laboratory roof for several days for different inclination angles and distances between rows. The results show that a top module on a row may generate 8% more power than a bottom module at noontime. The findings of this experimental study have technical significance in designing PV systems.

Positional error modeling of sky‐view factor measurements within urban street canyons

2021 ◽  
Author(s):  
Zian Wang ◽  
Guoan Tang ◽  
Guonian Lü ◽  
Cheng Ye ◽  
Fangzhuo Zhou ◽  
...  
Keyword(s):  
Error Modeling ◽  
View Factor ◽  
Positional Error ◽  
Street Canyons ◽  
Urban Street ◽  
Sky View Factor ◽  
Urban Street Canyons

scholarly journals Calculation of the irradiance of solar radiation in a greenhouse with a complex structure using a diagram for sky view factor

2020 ◽  
Vol 76 (1) ◽  
pp. 44-52
Author(s):  
Shuh MATSUDA ◽  
Hisashi YOSHIKOSHI ◽  
Tomoyo SUZUKI ◽  
Yuuki OHTA ◽  
Ayaka CHIBA ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Complex Structure ◽  
View Factor ◽  
Sky View Factor

Development of synthetic hemispheric projections suitable for assessing the sky view factor on vertical planes

2015 ◽  
Vol 74 ◽  
pp. 279-286 ◽  
Author(s):  
J. Ramírez-Faz ◽  
R. López-Luque ◽  
F.J. Casares
Keyword(s):  
View Factor ◽  
Sky View Factor

scholarly journals Application of Method for Calculating Sky View Factor Using Google Street View: Relation Between Sky View Factor and Physical Elements in Urban Space

2019 ◽  
Vol 2 ◽  
pp. 1-8
Author(s):  
Shoko Nishio ◽  
Fumiko Ito
Keyword(s):  
Urban Space ◽  
Computation Method ◽  
View Factor ◽  
Statistical Process ◽  
Google Street View ◽  
Sky View Factor ◽  
Street View ◽  
The Difference ◽  
Physical Elements

<p><strong>Abstract.</strong> We applied a computation method of calculating the sky view factor (SVF) using Google Street View to Shibuya area, Tokyo, for the purpose of examining the relation between the SVF/SVF change and physical elements. The distribution of the SVF calculated by the above method was visualized, and the statistical process showed the tendency of a high SVF in quasi-residential districts and roadsides of high-graded trunk roads. The difference in the SVF change was small at 10-m intervals. The SVF change tended to be more apparent near an intersection and at different elevations.</p>

Modeling the effective emissivity of the urban canopy using sky view factor

2015 ◽  
Vol 105 ◽  
pp. 211-219 ◽  
Author(s):  
Jinxin Yang ◽  
Man Sing Wong ◽  
Massimo Menenti ◽  
Janet Nichol
Keyword(s):  
Urban Canopy ◽  
View Factor ◽  
Effective Emissivity ◽  
Sky View Factor

scholarly journals Comparisons on Calculating Methods of Total Daily Global Solar Radiation in Urban Area Based on Panoramic Images

2019 ◽  
Vol 136 ◽  
pp. 05010
Author(s):  
Moyan Zhang ◽  
Yan Liu ◽  
Ruixin Chen ◽  
Xiangfei Guo ◽  
Weiqing Yuan ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Urban Area ◽  
Morphological Characteristics ◽  
Global Solar Radiation ◽  
View Factor ◽  
Sky View Factor ◽  
Panoramic Images ◽  
Rayman Model ◽  
Morphology Characteristics ◽  
Tree View

In this paper, the total daily global solar radiation is tested at 18 locations with different morphological characteristics in Xi’an University of Architecture and Technology. PTgui is used to convert the panoramic pictures from Baidu Street Map to fisheye images. Sky view factor (SVF) and tree view factor (TVF) are calculated by Rayman model with fisheye images. SVF is used to calculate the total daily global solar radiation at the 18 locations with two different methods and TVF is used to classify the locations. The calculations and testing results are compared and combined the morphological characteristics. Then it is found that using suitable methods on different locations is necessary to obtain more accurate results whether the TVF (tree view factor) is more than 0.3 or less. To obtain solar radiation at different locations in the urban area, the calculating methods should be carefully chosen based on the morphology characteristics of the location.

scholarly journals Automatic Sky View Factor Estimation from Street View Photographs—A Big Data Approach

2017 ◽  
Vol 9 (5) ◽  
pp. 411 ◽  
Author(s):  
Jianming Liang ◽  
Jianhua Gong ◽  
Jun Sun ◽  
Jieping Zhou ◽  
Wenhang Li ◽  
...  
Keyword(s):  
Big Data ◽  
View Factor ◽  
Sky View Factor ◽  
Street View ◽  
Factor Estimation

View Factors to Grounds of Photovoltaic Collectors

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
J. Appelbaum
Keyword(s):  
Global Radiation ◽  
Appreciable Amount ◽  
View Factor ◽  
Solar Pv ◽  
Mathematical Expressions ◽  
Inclination Angles ◽  
View Factors ◽  
Solar Field ◽  
Analytical Expressions ◽  
General Configuration

Ground reflected radiation is one component of the global radiation on photovoltaic collectors in a solar field. This component depends on the view factor of the collector to ground, hence depends on the relative position of the collectors to each other. General analytical expressions and numerical values for the view factor to the ground were developed between flat-plate collectors positioned in a general configuration. Based on the general expression, the view factors to ground for particular collector configurations were derived. For deployment of photovoltaic collectors in multiple rows with common inclination angles, the view factor to ground is rather small, and hence, the reflected radiation from the ground on the collectors may be neglected compared to the direct beam and the diffuse components. However, in some cases the reflected radiation from the ground may constitute an appreciable amount as in snowy area. Bifacial photovoltaic (PV) panels can absorb solar radiation by both the front and the rear sides and are usually deployed vertically. In this case the reflected radiation from the ground on the panels may be appreciable depending on the ground albedo. The mathematical expressions of the different view factors may be used by the solar field designer to estimate the amount of reflected radiation from the ground reaching the collectors for different configurations of solar PV plants.

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