Presented at 3rd International Conference on the Developments in Renewable Energy Technology, ICDRET 2014, on January 9-11, 2014 at Dhaka, Bangladesh http://icdret.uiu.ac.bd/ Award: Prof. H. Rashid Best Paper Presentation Award (2nd Position) Presented by: Samiul Alam

1. Sun Tracking Schemes
for
Photovoltaic Panels
Marzia Hoque Tania
Md. Samiul Alam

2. Objective
Design & implementation of Single axis tracker
Design & implementation of Dual axis tracker
Performance synopsis

3. Aspects of Sun Position

4. Source:Electropaedia
Aspects of Sun Position: Continue

6. A Solar tracker is a device for orienting a solar
photovoltaic panel or concentrating solar reflector or
lens toward the sun. The sun's position in the sky
varies both with the seasons (elevation) and time of
day as the sun moves across the sky.
A Solar Tracker

7. Solar Trackers
Considering movement capability-
 Fixed surfaces
 One axis trackers
 Two axes trackers
Regarding control units-
 Passive
 Microprocessor and
 Electro-optical
Picture: Market Electrification Systems at
Barkal Upazila under Rangamati District

8. Accuracy Requirement

9. Design & Implementation of the Systems

10. Block Diagram of Automatic Single Axis
Solar Tracking Scheme

11. System Implementation Flowchart of the Single
Axis Tracker
Legend
LDR1=Light Dependent Resistor at The East
LDR2=Light Dependent Resistor at The West
Forward Rotation=East to West
Reverse Rotation=West to East
Start
Input LDR1 & LDR2
LDR1<LDR2?
Rotate required step(East to West)
Get First Interrupt
Stop Forward Rotation
Reverse to Initial Stage
Get Second Interrupt
Stop Processing Until Getting The
Input
Activate The Load
Get Input?
End
Yes
No
Yes
No
Time Delay

12. Methodology and Operation of Designed Single
Axis Tracker

13. Block Diagram of Automatic Dual Axis Solar
Tracking Scheme

14. START
Take Input from the 4 sensors
Compare corresponding Inputs
Movement
Required?
Motor-1,
Motor-2
or both?
Check movement
combination for both
Give proper combination
of pulse for motors one
Forward or
Reverse?
Forward or
Reverse?
Give 1 Pulse
Reverse
Give 1 Pulse
Forward
Give 1 Pulse
Reverse
Give 1 Pulse
Forward
Motor 2Motor 1
Yes
No
Both
ForwardReverseForwardReverse
System Implementation Flowchart of the Dual
Axis Tracker

15. Response time: 1 sec
High precision
High accuracy
Availability of components
High convergence speed
Independence of PV characteristics
No need of statistical data over a long period
Gained power is almost constant over a period
of time
System Verification

16. Assessment of the Prototype: Single Axis
Tracker
No dead band found
Dynamic response
Least steady state error
Energy output increment ~ 21%
System can be operated with low maintenance
Low power requirement for circuits operation

17. Assessment of the Prototype: Dual Axis
Tracker
 Complex in hardware mechanism
 Energy increment: 33.5% (theoretical 42%)
 System power consumption is high
 System maintenance is excessive
 Less reliable in bad weather

18. Conclusion
Though the single axis tracker presented here shows
high precision and high accuracy to track the sun
and the dual axis tracker shows convincing energy
gain, these two trackers need to be upgraded to
improve-
 Mechanical System
 The sensors array
 The power supply
 Microprocessor functionality
 This design can be replicated to larger scale