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The Effect of Cooling on the Performance of Photovoltaic Cells under Dusty Environmental Conditions
Available online at www.sciencedirect.com
ScienceDirect Energy Procedia 61 (2014) 2383 – 2386
The 6th International Conference on Applied Energy – ICAE2014
The Effect of Cooling on the Performance of Photovoltaic Cells under Dusty Environmental Conditions A. Aldihania, A. Aldossarya, S. Mahmouda, R.K.AL-Dadaha* a School of Mechanical En gineering,University of Birmingham, Edgbaston, Birmingham, United Kingdom, B15-2TT.
Abstract Solar photovoltaic technology is a major form of renewable energy and is gaining worldwide interest due to rising energy demands and concerns of environmental effects. Kuwait is located on latitude of 29.220N and enjoys high solar radiation in most parts of the year (7.65 kWh/m2.day). However, Kuwait suffers from dust and sand storms due to its very little vegetation, dryness, weightless-textured surface soil and frequent unstable strong air currents. This work investigates the performance of solar PV panel based on HIT silicon cells under Kuwait environment and assesses the effect of cooling in reducing the impact of dust on the PV power output. Measurements showed that dust reduces the power output by 16% at midday. This effect can be partially compensated through cooling the PV panel. © 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license © 2014 The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and/or peer-review under responsibility of ICAE Peer-review under responsibility of the Organizing Committee of ICAE2014
Keywords: HIT Solar Cells, Cooling, Sand, IV characteristics
1. Introduction Kuwait is located on latitude of 29.220N and enjoys high solar radiation in most parts of the year (7.65 KWh/m2.day). However, Kuwait suffers from dust and sand storms due to its very little vegetation, dryness, weightless-textured surface soil and frequent unstable strong air currents [1]. The deposition of aerial dust on PV modules reduces their transmittance and cause a reduction in their power output and conversion efficiency [2-3]. This work experimentally investigates the performance of solar PV panel under Kuwait environment and numerically simulates the effect of cooling in reducing the impact of dust on the PV power output. Measurement of voltage, current, temperature and in plain solar radiation for clean and dusty solar panels was carried out with time on a daily basis over a period of one year. The solar panel used is made of HIT solar cells and has overall dimensions of 1580mmx798mm. Throughout this
* Corresponding author. Tel.: +44-0121-4143513; fax: +44-0121-4143598. E-mail address: [email protected].
1876-6102 © 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of the Organizing Committee of ICAE2014 doi:10.1016/j.egypro.2014.12.010
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A. Aldihani et al. / Energy Procedia 61 (2014) 2383 – 2386
period of measurement no planned cleaning procedure was applied. Figure 1 shows the daily measured current, voltage, radiation and temperatures for clean and dusty solar PV panels for the 18th of July 2013. It can be seen that the dusty panel produces lower current than the clean one by up to 1Amps at midday. However, the clean panel produced slightly lower voltage (average of 2Volts) than the dusty one and showed higher temperature values. This resulted in reducing the power output from 180W to 150W at noon due to dust. This work investigates the use of cooling to minimize the impact of dust. 2. Electrical and Thermal Modelling In order to assess the effect of temperature and dust on the panel performance, the clean HIT cell was modelled using the single diode solar cell circuit model [4]. Equations 1-3 describe the relationship between major parameters like output current, voltage, input radiation and temperature [4]. (1) where, I and V are the PV array or cell output current and voltage, q is the charge of an electron, k is the boltzman’s constant, T is the cell temperature, and A is the ideality factor of pn junction which determines the cell deviation from the ideal pn junction characteristic and it ranges from 1 to 5 where 1 is being the ideal value. Id, the cell reverse saturation current, varies with temperature according to the following equation: (2) where, Tc is the cell reference temperature (298.15K), Ic is the reverse saturation current at Tc, and Eg is the band gap energy of the semiconductor used in the cell. Iph the photo current relies on the solar radiation as well as the cell temperature as following: (3) where, Iscr is the short circuit current at reference temperature and radiation, Ki is the short circuit current temperature coefficient, and S is the solar irradiation in mW/cm2. Figure 2 shows the measured IV curves compared to the predicted ones at hours 9am, 12 noon and 15pm. It is clear from this figure that the model predictions were in close agreements with the measured ones. Using the dusty panel measured data, the validated model was used to predict the loss in radiation due to dust and investigate the effect of cooling on improving the power output of the dusty panel. Figure 3 shows the effect of decreasing the PV panel temperature on increasing the power output of the dusty panel throughout the day. It can be shown that an average of 2W/oC can be achieved during the noon time. Therefore a cooling system need to be investigated that can reduce the temperature of the dusty panels and partially offset the loss in PV power output. COMSOL multi-physics software was used to simulate the heat transfer process between the PV panel and the cooling system consisting of an array of rectangular channels with cross section of 100mm x2mm. The simulations were carried out to predict the average temperature of the PV cell at various water velocities ranging from 0.1mm/s to 5mm/s and different cooling water inlet temperatures (25oC to 49oC). Figure 4 shows that using cooling water with inlet temperature (T_in) of 40oC or lower the PV cell can be cooled by more than 20K. Therefore, it can be concluded that cooling of dusty PV panels can partially reduce the impact of the dust and improve the power output.
2385
1200
70
1000
60
Temperature [C]
Solar Radiation [W/m2]
A. Aldihani et al. / Energy Procedia 61 (2014) 2383 – 2386
800 600
Measured Radiation
400 200
50 40 30
Clean Dusty
20 10
0 04:48
07:12
09:36
12:00
14:24
16:48
0 04:48
19:12
07:12
09:36
Time
14:24
16:48
19:12
Time (b)
(a) 6
45
5
40
4 35
Current [A]
Voltage [V]
12:00
Clean
30
Dusty 25 20 04:48
07:12
09:36
12:00
14:24
16:48
3 2
Clean Dusty
1 0 04:48
19:12
07:12
09:36
Time
12:00
14:24
16:48
19:12
Time
(c) (d) Fig. 1. (a) Radiation, (b) temperature, (c) voltage and (d) current for clean and dusty PV panel 4.5
ϭϮ͗ϬϬŶŽŽŶ
5.0
3.0
Current (A)
3.5
Predicted Measured
2.5 2.0 1.5 1.0 0.5
4.0
Predicted Measured
3.0 2.0 1.0
0.0 0
0.2
0.4
0.6
0.8
0.0
Voltage (V)
0
0.2
4.0
0.4
Voltage (V)
ϭϱ͗ϬϬƉŵ
3.5 3.0
Current (A)
Current (A)
6.0
ϵ͗ϬϬĂŵ
4.0
2.5
Predicted Measured
2.0 1.5 1.0 0.5 0.0 0
0.2
0.4
0.6
0.8
Voltage (V) Fig. 2. Predicted and measured current versus voltage curves for clean PV panel
0.6
0.8
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A. Aldihani et al. / Energy Procedia 61 (2014) 2383 – 2386
T_in=322.15 T_in=308.15
T_in=317.15 T_in=298.15
T_in=313.15
PV cell average Temperature (K)
340 335 330 325 320 315 310 305 300 295 0
Fig. 3. Effect of temperature on power output of a dusty PV panel.
1
2
3
4
5
Inlet flow velocity (mm/s) Fig. 4. Effect of cooling water velocity on panel temperature
3. Conclusions Kuwait enjoys high solar radiation of 7.65 kWh/m2.day but suffers from dust storms that impact on the power output of solar PV panels. Experimental measurements for HIT PV panel has shown that the accumulated dust over a period of 12 months can lead to maximum loss in power output of 16% at noon for the July month. Numerical simulation results have shown that the use of cooling can partially compensate for this power loss. A water cooled panel with temperature reduction of 20K can improve the power output from 150W to 171W at midday. Such temperature drop can be achieved with water inlet temperature below 40 0C and velocity of 1mm/s. References [1] Al-Hurban A, Al-Ostad N. Textural characteristics of dust fallout and potential effect on public health in Kuwait city and suburbs, Environmental Earth Sciences 2010; 60:169-181. [2] Mani M, Pillai R. Impact of dust on solar photovoltaic (PV) performance: research status, challenges and recommendations, Renewable and Sustainable Energy Reviews 2010; 14 (9): 3124-3131. [3] Mekhilef S, Saidur R, Kamalisarvestani M, Effect of dust, humidity and air velocity on efficiency of photovoltaic cells, Renewable and Sustainable Energy Reviews 2012; 16: 2920-2925. [4] Singh G. Solar power generation by PV (photovoltaic) technology: A review, Energy 2013; 53: 1-12.
Biography Adel Aldihani has a Bachelor of Science degree in Electrical Engineering from University of Texas at San Antonio in (U.S. 2008). He obtained his M.Sc. in Engineering and Technology “Renewable Energy” from University of Northumbria (UK 2011). Currently, he is a PhD research student in Mechanical Engineering at University of Birmingham (UK).
ScienceDirect Energy Procedia 61 (2014) 2383 – 2386
The 6th International Conference on Applied Energy – ICAE2014
The Effect of Cooling on the Performance of Photovoltaic Cells under Dusty Environmental Conditions A. Aldihania, A. Aldossarya, S. Mahmouda, R.K.AL-Dadaha* a School of Mechanical En gineering,University of Birmingham, Edgbaston, Birmingham, United Kingdom, B15-2TT.
Abstract Solar photovoltaic technology is a major form of renewable energy and is gaining worldwide interest due to rising energy demands and concerns of environmental effects. Kuwait is located on latitude of 29.220N and enjoys high solar radiation in most parts of the year (7.65 kWh/m2.day). However, Kuwait suffers from dust and sand storms due to its very little vegetation, dryness, weightless-textured surface soil and frequent unstable strong air currents. This work investigates the performance of solar PV panel based on HIT silicon cells under Kuwait environment and assesses the effect of cooling in reducing the impact of dust on the PV power output. Measurements showed that dust reduces the power output by 16% at midday. This effect can be partially compensated through cooling the PV panel. © 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license © 2014 The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and/or peer-review under responsibility of ICAE Peer-review under responsibility of the Organizing Committee of ICAE2014
Keywords: HIT Solar Cells, Cooling, Sand, IV characteristics
1. Introduction Kuwait is located on latitude of 29.220N and enjoys high solar radiation in most parts of the year (7.65 KWh/m2.day). However, Kuwait suffers from dust and sand storms due to its very little vegetation, dryness, weightless-textured surface soil and frequent unstable strong air currents [1]. The deposition of aerial dust on PV modules reduces their transmittance and cause a reduction in their power output and conversion efficiency [2-3]. This work experimentally investigates the performance of solar PV panel under Kuwait environment and numerically simulates the effect of cooling in reducing the impact of dust on the PV power output. Measurement of voltage, current, temperature and in plain solar radiation for clean and dusty solar panels was carried out with time on a daily basis over a period of one year. The solar panel used is made of HIT solar cells and has overall dimensions of 1580mmx798mm. Throughout this
* Corresponding author. Tel.: +44-0121-4143513; fax: +44-0121-4143598. E-mail address: [email protected].
1876-6102 © 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of the Organizing Committee of ICAE2014 doi:10.1016/j.egypro.2014.12.010
2384
A. Aldihani et al. / Energy Procedia 61 (2014) 2383 – 2386
period of measurement no planned cleaning procedure was applied. Figure 1 shows the daily measured current, voltage, radiation and temperatures for clean and dusty solar PV panels for the 18th of July 2013. It can be seen that the dusty panel produces lower current than the clean one by up to 1Amps at midday. However, the clean panel produced slightly lower voltage (average of 2Volts) than the dusty one and showed higher temperature values. This resulted in reducing the power output from 180W to 150W at noon due to dust. This work investigates the use of cooling to minimize the impact of dust. 2. Electrical and Thermal Modelling In order to assess the effect of temperature and dust on the panel performance, the clean HIT cell was modelled using the single diode solar cell circuit model [4]. Equations 1-3 describe the relationship between major parameters like output current, voltage, input radiation and temperature [4]. (1) where, I and V are the PV array or cell output current and voltage, q is the charge of an electron, k is the boltzman’s constant, T is the cell temperature, and A is the ideality factor of pn junction which determines the cell deviation from the ideal pn junction characteristic and it ranges from 1 to 5 where 1 is being the ideal value. Id, the cell reverse saturation current, varies with temperature according to the following equation: (2) where, Tc is the cell reference temperature (298.15K), Ic is the reverse saturation current at Tc, and Eg is the band gap energy of the semiconductor used in the cell. Iph the photo current relies on the solar radiation as well as the cell temperature as following: (3) where, Iscr is the short circuit current at reference temperature and radiation, Ki is the short circuit current temperature coefficient, and S is the solar irradiation in mW/cm2. Figure 2 shows the measured IV curves compared to the predicted ones at hours 9am, 12 noon and 15pm. It is clear from this figure that the model predictions were in close agreements with the measured ones. Using the dusty panel measured data, the validated model was used to predict the loss in radiation due to dust and investigate the effect of cooling on improving the power output of the dusty panel. Figure 3 shows the effect of decreasing the PV panel temperature on increasing the power output of the dusty panel throughout the day. It can be shown that an average of 2W/oC can be achieved during the noon time. Therefore a cooling system need to be investigated that can reduce the temperature of the dusty panels and partially offset the loss in PV power output. COMSOL multi-physics software was used to simulate the heat transfer process between the PV panel and the cooling system consisting of an array of rectangular channels with cross section of 100mm x2mm. The simulations were carried out to predict the average temperature of the PV cell at various water velocities ranging from 0.1mm/s to 5mm/s and different cooling water inlet temperatures (25oC to 49oC). Figure 4 shows that using cooling water with inlet temperature (T_in) of 40oC or lower the PV cell can be cooled by more than 20K. Therefore, it can be concluded that cooling of dusty PV panels can partially reduce the impact of the dust and improve the power output.
2385
1200
70
1000
60
Temperature [C]
Solar Radiation [W/m2]
A. Aldihani et al. / Energy Procedia 61 (2014) 2383 – 2386
800 600
Measured Radiation
400 200
50 40 30
Clean Dusty
20 10
0 04:48
07:12
09:36
12:00
14:24
16:48
0 04:48
19:12
07:12
09:36
Time
14:24
16:48
19:12
Time (b)
(a) 6
45
5
40
4 35
Current [A]
Voltage [V]
12:00
Clean
30
Dusty 25 20 04:48
07:12
09:36
12:00
14:24
16:48
3 2
Clean Dusty
1 0 04:48
19:12
07:12
09:36
Time
12:00
14:24
16:48
19:12
Time
(c) (d) Fig. 1. (a) Radiation, (b) temperature, (c) voltage and (d) current for clean and dusty PV panel 4.5
ϭϮ͗ϬϬŶŽŽŶ
5.0
3.0
Current (A)
3.5
Predicted Measured
2.5 2.0 1.5 1.0 0.5
4.0
Predicted Measured
3.0 2.0 1.0
0.0 0
0.2
0.4
0.6
0.8
0.0
Voltage (V)
0
0.2
4.0
0.4
Voltage (V)
ϭϱ͗ϬϬƉŵ
3.5 3.0
Current (A)
Current (A)
6.0
ϵ͗ϬϬĂŵ
4.0
2.5
Predicted Measured
2.0 1.5 1.0 0.5 0.0 0
0.2
0.4
0.6
0.8
Voltage (V) Fig. 2. Predicted and measured current versus voltage curves for clean PV panel
0.6
0.8
2386
A. Aldihani et al. / Energy Procedia 61 (2014) 2383 – 2386
T_in=322.15 T_in=308.15
T_in=317.15 T_in=298.15
T_in=313.15
PV cell average Temperature (K)
340 335 330 325 320 315 310 305 300 295 0
Fig. 3. Effect of temperature on power output of a dusty PV panel.
1
2
3
4
5
Inlet flow velocity (mm/s) Fig. 4. Effect of cooling water velocity on panel temperature
3. Conclusions Kuwait enjoys high solar radiation of 7.65 kWh/m2.day but suffers from dust storms that impact on the power output of solar PV panels. Experimental measurements for HIT PV panel has shown that the accumulated dust over a period of 12 months can lead to maximum loss in power output of 16% at noon for the July month. Numerical simulation results have shown that the use of cooling can partially compensate for this power loss. A water cooled panel with temperature reduction of 20K can improve the power output from 150W to 171W at midday. Such temperature drop can be achieved with water inlet temperature below 40 0C and velocity of 1mm/s. References [1] Al-Hurban A, Al-Ostad N. Textural characteristics of dust fallout and potential effect on public health in Kuwait city and suburbs, Environmental Earth Sciences 2010; 60:169-181. [2] Mani M, Pillai R. Impact of dust on solar photovoltaic (PV) performance: research status, challenges and recommendations, Renewable and Sustainable Energy Reviews 2010; 14 (9): 3124-3131. [3] Mekhilef S, Saidur R, Kamalisarvestani M, Effect of dust, humidity and air velocity on efficiency of photovoltaic cells, Renewable and Sustainable Energy Reviews 2012; 16: 2920-2925. [4] Singh G. Solar power generation by PV (photovoltaic) technology: A review, Energy 2013; 53: 1-12.
Biography Adel Aldihani has a Bachelor of Science degree in Electrical Engineering from University of Texas at San Antonio in (U.S. 2008). He obtained his M.Sc. in Engineering and Technology “Renewable Energy” from University of Northumbria (UK 2011). Currently, he is a PhD research student in Mechanical Engineering at University of Birmingham (UK).