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Theoretical and experimental investigation of photovoltaic cell performance, with optimum tilted angle: Basra city case study
Case Studies in Thermal Engineering 14 (2019) 100421
Contents lists available at ScienceDirect
Case Studies in Thermal Engineering journal homepage: www.elsevier.com/locate/csite
Theoretical and experimental investigation of photovoltaic cell performance, with optimum tilted angle: Basra city case study
T
Ali K. Shaker Al-Sayyab∗, Zainab Y. Al Tmari, Maher K. Taher Southern Technical University, Iraq-Basra, Iraq
ARTICLE INFO
ABSTRACT
Keywords: Solar energy Photovoltaic cell Tilted angle
This work includes a theoretical and experimental study to evaluate the effect of a photovoltaic cell tilted angle variation on the generated power of a photovoltaic cell, located in Basra city. In this study, to find an optimum tilted angle, without using the tracking system, a mathematical model is used that is programmed by Mat lab R218a. This model was checked using an experimental test rig and the tilted angle varied across a range from 0° to 90°. The results show that this model is more accurate for tilted angle finding and indicates that the optimum yearly tilted angle of a photovoltaic cell located in Basra city (latitude 30° 30”) is equal to 28°.
1. Introduction In Iraq, Basra city's thermoelectric power plants use fossil fuels, which represent a major source of generated electricity; however, these plants are problematic due to the environmental impact and pollution caused by generating systems. Looking forward, the burning of fossil fuel generates CO2, which has an effect on global warming. Therefore, alternative sources must be considered for the near future. Compared with primary energy sources, solar electricity energy generation systems have some merits, such as energy-regeneration, cleanliness, no pollution, and safety [1]. At the present time, there are two major techniques for solar electricity energy generation: photovoltaic generation and solar-heated generation. There are some merits of solar photovoltaic technology, such as no noise, mechanical friction, and rotatable parts, but there are high generating costs and problems with inefficiency [2]. The PV cell orientation and tilt angle have more effect on the performance of photovoltaic [3]. Many studies adopted to predict the effect of photovoltaic cell orientation and tilts on its performance. The authors of [4] state that the optimum yearly tilt angle is equal to the latitude. The authors of [5] show that the tracking system has daily collected solar energy of 19%–24% higher than of fixed system. The authors of [6] demonstrates that the yearly optimum tilted angle winter is less from summer by 15° of location latitude. The authors of [7] reports that the PV array should be north facing in the southern hemisphere and the optimum tilt angle of PV array depends only on the latitude. The authors of [8] shows the monthly changing of the tilt angle of the PV cell achieves a solar radiation of approximately 30% more than of fixed one. The authors of [9] state that the optimum tilted angle for a PV cell array is difference from moth to other over the year. The authors of [9] show that the optimum tilt angle is directly proportion with location latitude. The authors of [10]did a theoretical study for finding optimum tilted angle for northern Iraq cites, they conclude that the optimum tilted angle is not equal to latitude. the author of [11,12] report that the optimum yearly tilted angle of a photovoltaic cell is not equal to location latitude. The authors of [13] concludes that the reliability increased with the increased system capacity. The simulated value became more accurate when the model was modified by weather conditions. authors of [16] Did a comparison between three methods for measure energy produced by photovoltaic modules integrated in various external opaque shadings of typical office buildings in Greece. The
Corresponding author. E-mail addresses: [email protected] (A.K. Shaker Al-Sayyab), [email protected] (Z.Y. Al Tmari), [email protected] (M.K. Taher). ∗
https://doi.org/10.1016/j.csite.2019.100421 Received 3 September 2018; Received in revised form 6 February 2019; Accepted 23 February 2019 Available online 28 February 2019 2214-157X/ Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Symbols description unit
hs N ID Θ
Photovoltaic cell Area, m2 Diffused solar radiation received by the horizontal plane, W/m2 Diffused solar radiation received by the titled photovoltaic cell, W/m2 Energy theoretically received per m2and per day, kWh/m2/day Electric Power, watt Global solar radiation received by the collector, W/m2 Global solar radiation received by the horizontal
Ac DH Di E Ew Gi GH
θz α β φ| η δ ΔD
plane, W/m2 Height of the sun at true solar midday, (°) Number of solar day Direct solar flux, W/m2 Angle formed by the normal to the collector and the solar rays incident, (°) Azimuth angle, (°) Albedo Photovoltaic cell tilted angle, (°) Latitude of the city, (°) Photovoltaic Cell efficiency Declination angle of the sun, (°) Duration of the day
results showed that the simple simulation and the more elaborated models have similar performance for most of the shading devices, apart from those with a complicated geometry. And the complete model that the difference of energy production per m2of venetian blind outwards inclined system and of canopy inclined system is 44.12% higher in the case of canopy inclined. the authors of [17] Study the effect on climate conditions on the performance of photovoltaic cell, they Conclude that in countries with a high solar potential and warm climate, PV system performance parameters are influenced, mainly, due to higher values of Tm, so the a-Si/m-Si PV modules show a better efficiency in summer. The authors of [18] did a comparison for different tracking system of parabolic solar water heater, they conclude that the model of North -South axis give the highest collected energy with 34% increase from East- West rotate mode. In current study, we present an experimental and simulation study to find the optimum yearly and monthly tilted angle for the PV cell located in Basra city (latitude 30°30′). The aim of this study is to: 1. Find the best monthly and yearly tilt angle of PV cell in Basra city 2. Verify the accuracy of the adopted model experimentally. Mathematical Method for the Optimum Tilted Angle. The solar irradiation from the sky is the combination of two components of the direct irradiation and the diffuse irradiation [14]. (see. Fig. 1) In this work, the Schwartz model [15] is used to find the optimum tilt angle ( ) of the photovoltaic cell in Basra city, due to it is a simplicity than other authors. In this model, the direct radiation is under three sky conditions: Clear:
ID = 1230e
1 3.8 sin(hs + 1.6)
(1)
Very Clear:
ID = 1210e
1 6 sin(hs + 1)
(2)
Polluted:
ID = 1260e
1 2.3 sin(hs + 3)
(3)
The diffused radiation for any sky conditions: (4)
DH = 125(sin(hs ))0.4 The total radiation received by the horizontal plane:
(5)
GH = DH + ID sin(hs ) Diffuse and total radiations receipts by the inclined collector plane:
2
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Fig. 1. Definition of solar and sky angles [10].
1 + cos( ) 1 DH + 2
Di =
cos( ) GH 2
(6) (7)
Gi = ID . cos( ) + Di
Where the factor is the coefficient of the reflexion of the ground located in front of the collector (usually taken equal to 0.2). and the angle formed between the normal of the collector and the solar rays at solar midday define by:
= 90
( + hs )
(8)
hs = 90
+
(9)
The Solar day length:
D=
2 Cosh 1 ( Tan ( ). tan( )) 15
= 23.45 sin 360°
(10)
(284 + N ) 365
(11)
Received energy:
E=
2
× Gi ×
D
(12)
The photovoltaic cell efficiency:
=
E
EW Ac
(13)
1.1. Test rig In this study, to check the accuracy of the mathematical model, a test rig (Fig. 2) was assembled comprising of: 1. 2. 3. 4.
Photovoltaic cell 24 W Fluke 3000 FC Series wattmeter with accuracy of 1% + 3 to measure the consumption power by load Four electric lamps (as load) connected in parallel to the cell Protractor to measure the cell tilted angle
3
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Fig. 2. Test Rig.
2. Results and discussion Optimum Monthly Tilted Angle. 2.1. Photovoltaic cell tilted angle vs. generated power To find the fixed tilted angle that gives higher generated electricity by photovoltaic cells over days of the month, the tilted angle will vary over a range of 0°–90° with a step of 5°. Fig. (3) shows that as the tilted angle increases, generated power will also increase due to growth in the amount of normal solar radiation that incidents to the cell's surface, the generated power reaches a value of which the tilted angle increases and the generated power decreases (maximum value).
Fig. 3. Effect of the tilted angle on the generated power by a photovoltaic cell located in Basra city.
2.2. Effect of solar day number on the tilted angle Fig. (4-A-B) show the effect of a tilted angle variation on the generated power by a photovoltaic cell located in Basra city on different days at the same time (12:00 p.m.) and during the same month (March). Both figures have the same phenomena of the effect of the tilted angle variation but are different in optimum-tilted angles due to differences in the solar-day number. The difference in the months offers variations in the declination angle, since each month differs in declination angles as shown in 4
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Fig. 4. Effect of tilted angle variation on generated power of a photovoltaic cell located in Basra city over different solar.
Fig. (5). As mentioned in Fig. (5), the declination angle of February is less than that of March. As the declining angle increases, the path of the sun's rays will decrease, and, in turn, this will decrease the solar beam, absorbing, and scattering, and increasing the flux of solar energy that reaches the photovoltaic surface, so that power generates more power; this explains why the generated power in March is more than that of February Fig. (4-B) and Fig. (4-C). Taking the same step using the mathematical models for all other months' optimum tilted angles can be found, see Fig. (6).
5
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Fig. 5. Declination angle variation with number of days.
Fig. 6. Optimum monthly tilted angle.
Fig. 7. Optimum monthly tilted angle of a photovoltaic cell.
2.3. Optimum yearly tilted angle The finding of optimum yearly tilted angles will get rid the consumption of electric power that is used to operate the tracking system and reduce the cost of system maintenance. The variation of the tilted angle will be adopted over the year. An average value of generated electric power over a year will be used as a method to find generated power by any tilted angle. Fig. (7) shows that there is one angle that gives maximum generated electric power over the year, and this angle can be taken as a yearly optimum tilted angle. This angle does not equal the latitude of Basra city (latitude 30.30°) and this refutes the claim of many studies that take optimum tilted angles as equal to latitude.
6
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
3. Conclusions 1) The monthly optimum tilted angle of a photovoltaic cell for each month is not equaled due to disparities in the declination angle. 2) For Basra city, the photovoltaic cell optimum yearly tilted angle is equal to 28°. 3) The predicted energy by the current model is more than experimental because of the model does not account the effect of ambient air temperature (heating) on photovoltaic performance. 4) The Schwartz's model is more accurate for finding the best-tilted angle of a photovoltaic cell. Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.csite.2019.100421. References [1] J. Byrne, B. Shen, W. Wallace, The economics of sustainable energy for rural development: a study of renewable energy in rural China, Energy Policy 26 (1) (1998) 45–54. [2] Fraunhofer - Institut Solare Energiesysteme - ISE, "Der Rappenecker Hof im 21. Jahrhundert", Freiburg - Germany, (October 2003) Available: www.ise. fraunhofer.de/german/fields/field3/mb1/materialien/rappeneckerhof.pdf. [3] Ashok Kumar, Optimization of tilt angle for photovoltaic array, Int. J. Eng. Sci. Technol. 3 (4 Apr) (2011). [4] O.C. Vilela, N. Fraidenraich, C. Tiba, Photovoltaic pumping systems driven by tracking collectors: experiments and simulation, Solar Energy jornal 74 (1) (2003) 45–52. [5] S.S.H. Soulayman, On “the optimum tilt of solar absorber plates”, Renew. Energy 1 (1991) 551–554. [6] Hamdy K. Elminir, Ahmed E. Ghitas, F. El-Hussainy, R. Hamid a, M.M. Beheary, Khaled M. Abdel-Moneim, Optimum solar flat-plate collector slope:Case study for Helwan, Egypt, Energy Convers. Manag. 47 (2006) 624–637. [7] Koray Ulgen, Optimum tilt angle for solar collectors, Energy Sources, Part A 28 (2006) 1171–1180. [8] Kamal Skeiker, Optimum tilt angle and orientation for solar collectors in Syria, Energy Convers. Manag. 2009 50 (2009) 2439–2448. [9] Hamid Moghadam, Farshad Farshchi Tabrizi, Ashkan Zolfaghari Sharak, Optimization of solar flat collector inclination, Desalination 265 (Issues 1–3) (15 January 2011) 107–111. [10] Ali Khalid Shaker Al-Sayyab , Maher Kadhim Taher, Optimum Tilted Angle of Photovoltaic Cell Located in Northern Iraq Cities to Get Maximum Generated Electric Power, National Renewable Energies Conference and Their Applications 2013. [11] Ali Khalid Shaker Al-Sayyab, Maher Kadhim Taher, Optimum yearly tilted angle of photovoltaic cell to receive maximum solar radiation in southern Iraq cities, thi-qar univ. J. Eng. Sci. 5 (1) (2014) 1–14. [12] Akeel M. Ali, Ali K. Shaker Al-Sayyab, Mohammed A. Abdulwahid, Optimisation of tilted angles of a photovoltaic cell to determine the maximum generated electric power: a case study of some Iraqi cities, Case Stud. Therm. Eng. 12 (2018). [13] Haiying Wang, Ninghui Zhu, Xiaomin Bai, Reliability model assessment of grid connected solar photovoltaic system based on Monte Carlo, Appl. Sol. Energy 51 (No. 4) (2015) 262–266. [14] Romdhane Ben Slama, Incidental solar radiation according to the solar collector slope -horizontal measurements conversion on an inclined panel laws”, Open Renew. Energy J. (2009) 52–58. [15] B.M. Schwartz, The Solar Radiation, Thermal Conversion and Applications; Technique and Documentation, twenty-first ed., (1980) Paris. [16] M. Mandalaki, S. Papantoniou, T. Tsoutsos, Assessment of energy production from photovoltaic modules integrated in typical shading devices, Sustain. Cities Soc. 10 (2014) 222–231. [17] Nikolaos Savvakis, Theocharis Tsoutsos, Performance assessment of a thin film photovoltaic system under actual Mediterranean climate conditions in the island of Crete, Energy 90 (Part 2) (October 2015) 1435–1455. [18] Maher K. Taher, Ali K. Shaker Al-Sayyab, Mohammed A. Abdulwahid, Investigation the performance of parabolic solar water heater with different tracking system-basra city case study, J. Eng. Appl. Sci. 14 (1) (2019) 145–152.
7
Contents lists available at ScienceDirect
Case Studies in Thermal Engineering journal homepage: www.elsevier.com/locate/csite
Theoretical and experimental investigation of photovoltaic cell performance, with optimum tilted angle: Basra city case study
T
Ali K. Shaker Al-Sayyab∗, Zainab Y. Al Tmari, Maher K. Taher Southern Technical University, Iraq-Basra, Iraq
ARTICLE INFO
ABSTRACT
Keywords: Solar energy Photovoltaic cell Tilted angle
This work includes a theoretical and experimental study to evaluate the effect of a photovoltaic cell tilted angle variation on the generated power of a photovoltaic cell, located in Basra city. In this study, to find an optimum tilted angle, without using the tracking system, a mathematical model is used that is programmed by Mat lab R218a. This model was checked using an experimental test rig and the tilted angle varied across a range from 0° to 90°. The results show that this model is more accurate for tilted angle finding and indicates that the optimum yearly tilted angle of a photovoltaic cell located in Basra city (latitude 30° 30”) is equal to 28°.
1. Introduction In Iraq, Basra city's thermoelectric power plants use fossil fuels, which represent a major source of generated electricity; however, these plants are problematic due to the environmental impact and pollution caused by generating systems. Looking forward, the burning of fossil fuel generates CO2, which has an effect on global warming. Therefore, alternative sources must be considered for the near future. Compared with primary energy sources, solar electricity energy generation systems have some merits, such as energy-regeneration, cleanliness, no pollution, and safety [1]. At the present time, there are two major techniques for solar electricity energy generation: photovoltaic generation and solar-heated generation. There are some merits of solar photovoltaic technology, such as no noise, mechanical friction, and rotatable parts, but there are high generating costs and problems with inefficiency [2]. The PV cell orientation and tilt angle have more effect on the performance of photovoltaic [3]. Many studies adopted to predict the effect of photovoltaic cell orientation and tilts on its performance. The authors of [4] state that the optimum yearly tilt angle is equal to the latitude. The authors of [5] show that the tracking system has daily collected solar energy of 19%–24% higher than of fixed system. The authors of [6] demonstrates that the yearly optimum tilted angle winter is less from summer by 15° of location latitude. The authors of [7] reports that the PV array should be north facing in the southern hemisphere and the optimum tilt angle of PV array depends only on the latitude. The authors of [8] shows the monthly changing of the tilt angle of the PV cell achieves a solar radiation of approximately 30% more than of fixed one. The authors of [9] state that the optimum tilted angle for a PV cell array is difference from moth to other over the year. The authors of [9] show that the optimum tilt angle is directly proportion with location latitude. The authors of [10]did a theoretical study for finding optimum tilted angle for northern Iraq cites, they conclude that the optimum tilted angle is not equal to latitude. the author of [11,12] report that the optimum yearly tilted angle of a photovoltaic cell is not equal to location latitude. The authors of [13] concludes that the reliability increased with the increased system capacity. The simulated value became more accurate when the model was modified by weather conditions. authors of [16] Did a comparison between three methods for measure energy produced by photovoltaic modules integrated in various external opaque shadings of typical office buildings in Greece. The
Corresponding author. E-mail addresses: [email protected] (A.K. Shaker Al-Sayyab), [email protected] (Z.Y. Al Tmari), [email protected] (M.K. Taher). ∗
https://doi.org/10.1016/j.csite.2019.100421 Received 3 September 2018; Received in revised form 6 February 2019; Accepted 23 February 2019 Available online 28 February 2019 2214-157X/ Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Symbols description unit
hs N ID Θ
Photovoltaic cell Area, m2 Diffused solar radiation received by the horizontal plane, W/m2 Diffused solar radiation received by the titled photovoltaic cell, W/m2 Energy theoretically received per m2and per day, kWh/m2/day Electric Power, watt Global solar radiation received by the collector, W/m2 Global solar radiation received by the horizontal
Ac DH Di E Ew Gi GH
θz α β φ| η δ ΔD
plane, W/m2 Height of the sun at true solar midday, (°) Number of solar day Direct solar flux, W/m2 Angle formed by the normal to the collector and the solar rays incident, (°) Azimuth angle, (°) Albedo Photovoltaic cell tilted angle, (°) Latitude of the city, (°) Photovoltaic Cell efficiency Declination angle of the sun, (°) Duration of the day
results showed that the simple simulation and the more elaborated models have similar performance for most of the shading devices, apart from those with a complicated geometry. And the complete model that the difference of energy production per m2of venetian blind outwards inclined system and of canopy inclined system is 44.12% higher in the case of canopy inclined. the authors of [17] Study the effect on climate conditions on the performance of photovoltaic cell, they Conclude that in countries with a high solar potential and warm climate, PV system performance parameters are influenced, mainly, due to higher values of Tm, so the a-Si/m-Si PV modules show a better efficiency in summer. The authors of [18] did a comparison for different tracking system of parabolic solar water heater, they conclude that the model of North -South axis give the highest collected energy with 34% increase from East- West rotate mode. In current study, we present an experimental and simulation study to find the optimum yearly and monthly tilted angle for the PV cell located in Basra city (latitude 30°30′). The aim of this study is to: 1. Find the best monthly and yearly tilt angle of PV cell in Basra city 2. Verify the accuracy of the adopted model experimentally. Mathematical Method for the Optimum Tilted Angle. The solar irradiation from the sky is the combination of two components of the direct irradiation and the diffuse irradiation [14]. (see. Fig. 1) In this work, the Schwartz model [15] is used to find the optimum tilt angle ( ) of the photovoltaic cell in Basra city, due to it is a simplicity than other authors. In this model, the direct radiation is under three sky conditions: Clear:
ID = 1230e
1 3.8 sin(hs + 1.6)
(1)
Very Clear:
ID = 1210e
1 6 sin(hs + 1)
(2)
Polluted:
ID = 1260e
1 2.3 sin(hs + 3)
(3)
The diffused radiation for any sky conditions: (4)
DH = 125(sin(hs ))0.4 The total radiation received by the horizontal plane:
(5)
GH = DH + ID sin(hs ) Diffuse and total radiations receipts by the inclined collector plane:
2
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Fig. 1. Definition of solar and sky angles [10].
1 + cos( ) 1 DH + 2
Di =
cos( ) GH 2
(6) (7)
Gi = ID . cos( ) + Di
Where the factor is the coefficient of the reflexion of the ground located in front of the collector (usually taken equal to 0.2). and the angle formed between the normal of the collector and the solar rays at solar midday define by:
= 90
( + hs )
(8)
hs = 90
+
(9)
The Solar day length:
D=
2 Cosh 1 ( Tan ( ). tan( )) 15
= 23.45 sin 360°
(10)
(284 + N ) 365
(11)
Received energy:
E=
2
× Gi ×
D
(12)
The photovoltaic cell efficiency:
=
E
EW Ac
(13)
1.1. Test rig In this study, to check the accuracy of the mathematical model, a test rig (Fig. 2) was assembled comprising of: 1. 2. 3. 4.
Photovoltaic cell 24 W Fluke 3000 FC Series wattmeter with accuracy of 1% + 3 to measure the consumption power by load Four electric lamps (as load) connected in parallel to the cell Protractor to measure the cell tilted angle
3
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Fig. 2. Test Rig.
2. Results and discussion Optimum Monthly Tilted Angle. 2.1. Photovoltaic cell tilted angle vs. generated power To find the fixed tilted angle that gives higher generated electricity by photovoltaic cells over days of the month, the tilted angle will vary over a range of 0°–90° with a step of 5°. Fig. (3) shows that as the tilted angle increases, generated power will also increase due to growth in the amount of normal solar radiation that incidents to the cell's surface, the generated power reaches a value of which the tilted angle increases and the generated power decreases (maximum value).
Fig. 3. Effect of the tilted angle on the generated power by a photovoltaic cell located in Basra city.
2.2. Effect of solar day number on the tilted angle Fig. (4-A-B) show the effect of a tilted angle variation on the generated power by a photovoltaic cell located in Basra city on different days at the same time (12:00 p.m.) and during the same month (March). Both figures have the same phenomena of the effect of the tilted angle variation but are different in optimum-tilted angles due to differences in the solar-day number. The difference in the months offers variations in the declination angle, since each month differs in declination angles as shown in 4
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Fig. 4. Effect of tilted angle variation on generated power of a photovoltaic cell located in Basra city over different solar.
Fig. (5). As mentioned in Fig. (5), the declination angle of February is less than that of March. As the declining angle increases, the path of the sun's rays will decrease, and, in turn, this will decrease the solar beam, absorbing, and scattering, and increasing the flux of solar energy that reaches the photovoltaic surface, so that power generates more power; this explains why the generated power in March is more than that of February Fig. (4-B) and Fig. (4-C). Taking the same step using the mathematical models for all other months' optimum tilted angles can be found, see Fig. (6).
5
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
Fig. 5. Declination angle variation with number of days.
Fig. 6. Optimum monthly tilted angle.
Fig. 7. Optimum monthly tilted angle of a photovoltaic cell.
2.3. Optimum yearly tilted angle The finding of optimum yearly tilted angles will get rid the consumption of electric power that is used to operate the tracking system and reduce the cost of system maintenance. The variation of the tilted angle will be adopted over the year. An average value of generated electric power over a year will be used as a method to find generated power by any tilted angle. Fig. (7) shows that there is one angle that gives maximum generated electric power over the year, and this angle can be taken as a yearly optimum tilted angle. This angle does not equal the latitude of Basra city (latitude 30.30°) and this refutes the claim of many studies that take optimum tilted angles as equal to latitude.
6
Case Studies in Thermal Engineering 14 (2019) 100421
A.K. Shaker Al-Sayyab, et al.
3. Conclusions 1) The monthly optimum tilted angle of a photovoltaic cell for each month is not equaled due to disparities in the declination angle. 2) For Basra city, the photovoltaic cell optimum yearly tilted angle is equal to 28°. 3) The predicted energy by the current model is more than experimental because of the model does not account the effect of ambient air temperature (heating) on photovoltaic performance. 4) The Schwartz's model is more accurate for finding the best-tilted angle of a photovoltaic cell. Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.csite.2019.100421. References [1] J. Byrne, B. Shen, W. Wallace, The economics of sustainable energy for rural development: a study of renewable energy in rural China, Energy Policy 26 (1) (1998) 45–54. [2] Fraunhofer - Institut Solare Energiesysteme - ISE, "Der Rappenecker Hof im 21. Jahrhundert", Freiburg - Germany, (October 2003) Available: www.ise. fraunhofer.de/german/fields/field3/mb1/materialien/rappeneckerhof.pdf. [3] Ashok Kumar, Optimization of tilt angle for photovoltaic array, Int. J. Eng. Sci. Technol. 3 (4 Apr) (2011). [4] O.C. Vilela, N. Fraidenraich, C. Tiba, Photovoltaic pumping systems driven by tracking collectors: experiments and simulation, Solar Energy jornal 74 (1) (2003) 45–52. [5] S.S.H. Soulayman, On “the optimum tilt of solar absorber plates”, Renew. Energy 1 (1991) 551–554. [6] Hamdy K. Elminir, Ahmed E. Ghitas, F. El-Hussainy, R. Hamid a, M.M. Beheary, Khaled M. Abdel-Moneim, Optimum solar flat-plate collector slope:Case study for Helwan, Egypt, Energy Convers. Manag. 47 (2006) 624–637. [7] Koray Ulgen, Optimum tilt angle for solar collectors, Energy Sources, Part A 28 (2006) 1171–1180. [8] Kamal Skeiker, Optimum tilt angle and orientation for solar collectors in Syria, Energy Convers. Manag. 2009 50 (2009) 2439–2448. [9] Hamid Moghadam, Farshad Farshchi Tabrizi, Ashkan Zolfaghari Sharak, Optimization of solar flat collector inclination, Desalination 265 (Issues 1–3) (15 January 2011) 107–111. [10] Ali Khalid Shaker Al-Sayyab , Maher Kadhim Taher, Optimum Tilted Angle of Photovoltaic Cell Located in Northern Iraq Cities to Get Maximum Generated Electric Power, National Renewable Energies Conference and Their Applications 2013. [11] Ali Khalid Shaker Al-Sayyab, Maher Kadhim Taher, Optimum yearly tilted angle of photovoltaic cell to receive maximum solar radiation in southern Iraq cities, thi-qar univ. J. Eng. Sci. 5 (1) (2014) 1–14. [12] Akeel M. Ali, Ali K. Shaker Al-Sayyab, Mohammed A. Abdulwahid, Optimisation of tilted angles of a photovoltaic cell to determine the maximum generated electric power: a case study of some Iraqi cities, Case Stud. Therm. Eng. 12 (2018). [13] Haiying Wang, Ninghui Zhu, Xiaomin Bai, Reliability model assessment of grid connected solar photovoltaic system based on Monte Carlo, Appl. Sol. Energy 51 (No. 4) (2015) 262–266. [14] Romdhane Ben Slama, Incidental solar radiation according to the solar collector slope -horizontal measurements conversion on an inclined panel laws”, Open Renew. Energy J. (2009) 52–58. [15] B.M. Schwartz, The Solar Radiation, Thermal Conversion and Applications; Technique and Documentation, twenty-first ed., (1980) Paris. [16] M. Mandalaki, S. Papantoniou, T. Tsoutsos, Assessment of energy production from photovoltaic modules integrated in typical shading devices, Sustain. Cities Soc. 10 (2014) 222–231. [17] Nikolaos Savvakis, Theocharis Tsoutsos, Performance assessment of a thin film photovoltaic system under actual Mediterranean climate conditions in the island of Crete, Energy 90 (Part 2) (October 2015) 1435–1455. [18] Maher K. Taher, Ali K. Shaker Al-Sayyab, Mohammed A. Abdulwahid, Investigation the performance of parabolic solar water heater with different tracking system-basra city case study, J. Eng. Appl. Sci. 14 (1) (2019) 145–152.
7