1. Impact of Tilt Angle on the Performance of
Photovoltaic Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA
University of Malaya
Mohammad Abdullah Al Mamun
Md. Hasanuzzaman
Jeyraj A/l Selvaraj

2. Presentation contents
 Introduction
 Methodology
 Optimum tilt angle determination
 Tilt angle-latitude relations
 Results and Discussion
 Optimization tilt angle
 Tilt angle-latitude trade off
 Optimum tilt angle mapping
 Conclusion
2
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

3. Introduction
3
• For Maximum energy harvest from PV
the module must face normal to the sun
• This dependent on:
• Latitude of the site of installation
• Seasonal variation
• PV output depends on
• Orientation of the module
• Tilt angle
• Tracking
• Fixed PV array: latitude angle-declination
• Single-axis tracker:
 Changing 15° per hour a day
 Require additional focus
Single-axis tracker
Fixed PV array
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

4. Introduction …contd.
4
 Dual-axis trackers: 40% increased energy harvest
compared to fixed arrays
 Mechanical or electromechanical devices
 Slightly more expensive
 More maintenance and repair required
 More complex system
 Solar Tracking uses software to calculate the sun’s track based on latitude, longitude, date
and time
 Changing tilt angle and orientation of the PV panel monthly, seasonal or yearly might be
more possible than relating a dynamic sun tracker
Dual-axis tracker
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

5. Introduction …contd.
5
• Latitude: Angular height of the sun
with module.
• Azimuth angle: Compass direction
from which the sunlight is coming.
azimuth angle required
• Corrected solar panel orientation
varies with the latitude and time of
year.
Declination angle
• Declination: Rotation of the
Earth around the sun
• Declination is zero at March 22
and September 22
• Declination reaches 23.45° on
June 22 and -23.45° on
December 22
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

6. Introduction …contd.
6
 PV output increase by 5.6% using adjusted tilt angle (Mahmoud and Nabhan, 1990)
 Monthly change in tilt angle helps to capture 5% more solar irradiation
yearly compared to fixed PV system (Yakup and Malik, 2001)
 For South Africa, optimum tilt angle = latitude angle + 10° (Khatib et. al., 2012)
 For USA, optimum tilt angle = latitude angle + 20° (Tang and Wu, 2004)
 Optimal tilt angle 10° for Sabah and Sarawak (Weixiang, 2008)
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

7. Optimum tilt angle determination
• Mathematically define the optimal tilt angle
Tilt angle-latitude relations
• Determined the optimum tilt angle for particular
latitude site
Methodology
7
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

8. Optimum tilt angle determination
8
𝑯 𝑻 = 𝑯 𝒈 − 𝑯 𝒅 𝑹 𝒃 + 𝑯 𝒈 𝝆
𝟏 − 𝒄𝒐𝒔 𝜷
𝟐
+ 𝑯 𝒅 𝑹 𝒅Total solar irradiation:
𝒅
𝒅𝜷
𝑯 𝑻 = 𝟎
𝒅
𝒅𝜷
𝑹 𝒃 = 𝟎
⇒
𝒔𝒊𝒏 𝝋−𝜷 𝒄𝒐𝒔 𝜹 𝒔𝒊𝒏 𝝎 𝒔−
𝝅
𝟏𝟖𝟎
𝝎 𝒔 𝒄𝒐𝒔 𝝋−𝜷 𝒔𝒊𝒏 𝜹
𝒄𝒐𝒔 𝝋 𝒄𝒐𝒔 𝜹 𝒔𝒊𝒏 𝝎 𝒔+
𝝅
𝟏𝟖𝟎
𝝎 𝒔 𝒔𝒊𝒏 𝝋 𝒔𝒊𝒏 𝜹
⇒ 𝜷 = 𝝋 − 𝒕𝒂𝒏−𝟏
𝝅
𝟏𝟖𝟎
𝝎 𝒔 𝒔𝒊𝒏 𝜹
𝒄𝒐𝒔 𝜹 𝒄𝒐𝒔 𝝎 𝒔
Fixed orientation:
Optimum tilt angle:
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

9. Tilt angle-latitude relations
9
 Thumb rules
Solar panels should be more vertical during winter
to gain most of the low winter sun
More tilted during summer to maximize the
output
 Solar power plants use this relationship for
solar panel installation
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

10. Results and Discussion
 Optimization of tilt angle
Optimize monthly and seasonal tilt angles for Malaysia
 Tilt angle- latitude trade off
Find out optimum tilt angle for Malaysia base on latitude
 Optimum tilt angle mapping
Structure five locations are taken into account having the
latitude
10
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

11. Optimization of tilt angle
0
5
10
15
20
25
30
35
1 2 3 4 5 6 7 8 9 10 11 12
OPtimumtiltangle(deg.)
Month
Kuala Lampur Johor Bahru
Ipoh Kuching
Alor Setar
Figure 1: Optimum tilt angle versus month for five locations in Malaysia.
11
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

12. Optimization of tilt angle
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
0 10 20 30 40 50 60 70 80
SolarEnergy(KWh/m2)
Surface tilt angle (deg.)
FEB
JAN
NOV
DEC
OCT
MAR
APR,MAY, JUN,
JULY, AUG & SEP
OPTIMUM TILT ANGLE
Figure 2: Optimal tilt angles determined monthly for Kuala Lumpur.
12
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

13. Optimization of tilt angle
-30
-20
-10
0
10
20
30
1 2 3 4 5 6 7 8 9 10 11 12
Declinationat15thineachmonth
Month
Figure 3: Solar PV module declination in Kuala
Lumpur.
-20
-10
0
10
20
30
0 50 100 150 200 250 300 350
Surfacetiltangle(deg.)
Date of the year
Figure 4: The relationship between surface tilt angle and
date of the year in Perlis, Malaysia.
13
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

14. Optimization of tilt angle
3
3.5
4
4.5
5
5.5
6
1 2 3 4 5 6 7 8 9 10 11 12
SolarEnergy(KWh/m2)
Month
Kuala Lumpur Johor Bahru
Ipoh Kuching
Alor Setar
Wet
season
Dry season Wet
season
Figure 5: Monthly average solar PV energy production for five locations in Malaysia
14
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

15. Tilt angle-latitude trade-off
Latitude angle Tilt angle
0-15o 15o
15-25o Same as latitude angle
25-30o + 5o to local latitude
angle
30-35o + 10o to local latitude
angle
35-40o + 15o to local latitude
angle
40o+ + 20o to local latitude
angle
Table 1: Solar PV panel tilt angle
References Recommended tilt
angle
Remarks
Duffie and
Beckman
(𝜙 + 15°) ± 15°
Negative
sign is for
summer
and
positive
sign for
winter
season
Chinnery (𝜙 + 10°)
Elminir et al. (𝜙 + 15°) ± 15°
Heywood (𝜙 − 10°)
Hottel (𝜙 + 20°)
Garg 𝜙 + 15o, 𝜙 − 15o,
0.9𝜙
Lunde (𝜙 ± 15°)
Kern and harris (𝜙 + 10°)
Lof and Tybout 𝜙 + (10° → 30°)
Yellot (𝜙 + 20°)
Table 2: Optimum tilt angle-latitude angle relations
15
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

16. Tilt angle-latitude trade-off
-20
-15
-10
-5
0
5
10
15
20
25
30
1 2 3 4 5 6 7 8 9 10 11 12
Tiltangle(deg.)
Month
Tilt=Latitude
Tilt =0 deg.
Tilt =Latitude-Declination
Figure 6: Tilt angle versus months.
Figure 7: The relationship between the tilt angle
and date of the year.
16
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA
-20
-15
-10
-5
0
5
10
15
20
25
30
0 50 100 150 200 250 300 350
Tiltangle(deg.)
Date of the year
Tilt=Latitude
Tilt=0 deg.
Tilt= Latitude-Declination

17. Optimum tilt angle mapping
Figure 8: optimum tilt angle mapping of Malaysia
Location Latitude
Site
Location
Zone
Kuala Lumpur 3.8o
Zone A
Selangor 3.07o
Negeri
Sembilan
2.73o
Malacca 2.19o
Pahang 3.81o
Sarawak 1.55o
Johor Bahru 1.27o Zone B
Perak 4.59o Zone C
Terengganu 5.31o Zone D
Penang 5.41o
Zone E
Perlis 6.44o
Kedah 6.12o
Kelantan 6.13o
Sabah 5.98o
Table 3: Latitude angle at different
sites in Malaysia
17
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA

18. Conclusion
 Compared to the fixed tilted panels, seasonal adjustments can
provide up to 40% more solar energy
 The optimum tilt angle of Malaysia is 15o
 By changing the optimal tilt angles seasonally, the PV output for
Johor Bharu, Kuala Lumpur, Ipoh, Alor Setar and Kuching increase by
5.02, 5.03, 5.65, 6.13 and 7.96% respectively
 While changing the optimal tilt angle monthly for the same areas, the
collected yields increases by 4.58, 4.54, 5.70, 5.85 and 4.11%
respectively
 The tilt angle of a solar panel should be adequate to receive
maximum solar irradiation and to avoid partial shading
Impact of Tilt Angle on the Performance of Photovoltaic
Modules in Malaysia: A review
4th IET International Conference on Clean Energy and Technology, CEAT, 2016
14-15 November, 2016, Kuala Lumpur, MALAYSIA 18

19. Thank you
19