This document discusses solar trackers, which are devices that orient solar panels toward the sun for increased efficiency. It describes the need for solar tracking to maintain optimal sunlight absorption as the sun's position changes daily and seasonally. The key types of solar trackers are single-axis and dual-axis models. It also outlines the basic components, working mechanisms, applications, advantages like increased efficiency, and disadvantages like higher costs compared to fixed panels. Cost-benefit analyses show that trackers can increase energy output by 10-15% with only a 7-8% increase in investment costs.

1. Submitted by
Seyed Samsamoddin Naghavi Chaleshtori
University of Pune

2. CONTENTS
 Introduction
 What is a Solar Tracker ?
 Need for a Sun Tracking System
 Condition for Maximum Output
Types of solar trackers
 Basic Components
 The Working
 Applications
 Advantages & Disadvantages
Economic of solar trackers
 Conclusion

3. INTRODUCTION
 Conventional Energy
 Depletion of them
 Renewable Energy
 PV
 Azimuth and declination angle and Position of the sun

4. How the Track Rack follow the sun
1.Sunrise "Wake- Up
The Track Rack begins the
day facing west. As the
morning sun rises in the
east, it heats the unshaded
west-side canister with both.
2. Mid-Morning
The Track Rack moved by the shifting
weight of liquid flowing from one side
of the tracker to the other through a
copper tube that connects the east and
3. Mid-Afternoon
As the sun moves, the Track
Rack follows (at approximately
15o per hour, continually
seeking equilibrium as liquid
moves from one side of the
tracker to the other.
4. Sunset
The Track Rack completes its daily
cycle facing west. It remains in this
position overnight until it is
"awakened" by the rising sun the
following morning.
direct and reflected rays (from the inter surface
of the "shadow plate") forcing liquid into the
shaded east-side cannister.
west canisters .When one canister is exposed to the sun
more than the other, its vapor pressure increases, forcing
liquid to the cooler, shaded side.

5.  Solar arrays are being used increasingly as efficiencies reach
higher levels, and are especially popular in remote areas where
placement of electricity lines are not economically viable.
 For further optimization of these panels solar trackers are being
implemented, which enhances the efficiency of panels by 30-35 %.

6. What is a solar Tracker ?
 A solar tracker is a generic term used to describe devices that orient or
align various payloads toward the sun.
 Example for payloads are photovoltaic panels, reflectors, Collectors,
lenses or other optical devices.
 The system focuses on the optimization of the electric energy
produced by photovoltaic cells through the development of a sun-
tracking system.

7. Need For A Sun Tracking System
 From dawn to dusk the sun keeps changing the angle from 0-90 rising
and 90-180 declining.
 In a year of 365 days the sun moves approximately 22.5 degrees north
to 22.5 degrees south of the equator.
 We get maximum energy from the sun when
 - The angle of the sun is perpendicular to surface
 - The sun’s position is 0 +/- 5 degrees of the equator

8. The main reason to use a solar tracker is to reduce the cost of the
energy you want to capture. A tracker produces more power over a
longer time than a stationary array with the same number of
modules. This additional output or “gain” can be quantified as a
percentage of the output of the stationary array. Gain varies
significantly with latitude, climate, and the type of tracker you
choose—as well as the orientation of a stationary installation in the
same location.
Climate is the most important factor. The more sun and less
clouds, moisture, haze, dust, and smog, the greater the gain
provided by trackers. At higher latitudes gain will be increased due
to the long arc of the summer sun. In the cloudiest, haziest
locations the gain in annual output from trackers can be in the low
20 percent range.

10. Seasonal Variations in Output:
Gain from trackers is much greater during the long days of summer than
in winter. There is strong sun for many additional hours, including the
utility’s peak use hours (noon to 6 pm). If
your system is connected to the grid and your utility has time-of-day
metering, the tracker’s ability to capture all the afternoon sun can mean
money in your pocket. Time-of-day metering means that utilities
purchase excess power during peak hours in summer at a significant
premium, adding even more value to a tracker system. On off-grid
systems, however, a tracker may not add as much value if a stationary
array will produce all the power you need in summer.

11. A tracking system helps the solar panels keep oriented to the sun at
the optimum possible angle.
The tracking system improves the efficiency of solar panels by 30%
for single axis and an additional 6% for dual axis.

13. The graph above compares output, over the course of a year, for full tracking and a stationary
array with the same number of modules in Sacramento, CA. The data is from National
Renewable Energy Laboratory (NREL) web site:
http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/

14. Conditions For Maximum Output
 The difference between the incident ray and the reflected ray should
be equal to zero, i.e. the rays should be perpendicular to the panel.
 The altitude is directly proportional to the efficiency of the system up
to a certain limit.
 Very clear sky and clean atmosphere contributes a bit more to the
efficiency of the system.

15. Types of solar trackers
I. Single-axis
II. Dual-axis

16. Polar type single-axis tracker

17. Horizontal type single-axis trackers

18. Single-axis tubular solar technology

19. Dual-axis solar tracker

20. Basic Components
 The Solar Panel
 Stepper Motor
 Actuator
 Microcontroller
 A Display Unit (Optional)
 Interfacing Cables

21. The Inputs
 The various positions of the sun over a year for a particular
geographical location is given as the primary input to the
microcontroller.
 The irradiance of the sun for a particular geographical location over
a year is the secondary input for the microcontroller.
 The real time clocking is enabled in the microcontroller.

22. Controlling Constraints
• The microcontroller is programmed to orient the panel at optimum
position against the sun, via comparing to the inputs given.
• The microcontroller is set with a lower tolerance for the voltage
produced.
• If the voltage produced is above the tolerance then it holds the
position of the panel.
• If the voltage falls below the tolerance, then the panel changes the
position in the forward direction.

23.  This voltage tolerance varies according to various seasons. Like
summer has the highest voltage tolerance value.
 A second voltage tolerance is given, so as to switch off the
system when it falls beyond the tolerance.
 This will help in cloudy and rainy days.
 A panel will be reset to its default position at the end of the day
and starts again the next day. This is accomplished by a timer &
angle limits.

24. Applications
 Can be used for small & medium scale power generations.
 For power generation at remote places where power lines are
not accessible.
 For domestic backup power systems.

25. Advantages
 Solar tracking systems continually orient photovoltaic panels
towards the sun and can help maximize your investment in
your PV system.
 One time investment, which provides higher efficiency &
flexibility on dependency over other sources.
 Tracking systems can help reducing emissions and can
contribute against global warming.
 Bulk implementations of tracking systems help reduced
consumption of power by other sources.
 It enhances the clean and emission free power production.

26. Cause smaller size of array
Low height and minimum visual impact.
Optimization of occupied space by increasing the power
density of the park.
Less expensive invertor and other components
All movements with DC motors
Minimum consumption per machine

27. Disadvantages
 Initial investment is high on solar panels.
 It’s a bit of difficult for servicing, as the tracking systems are not
quite popular regionally.
 Moving parts and gears which will require regular maintenance.
 May require repair or replacement of broken parts over a long
run.

28. Fixed tilt Single axis tracker
Capacity 1 MW Capacity 1 MW
Electricity generation 1.6 million unit per
annum
Electricity generation 1.9 million unit per
annum
Capital
cost(approximately)
6 crore rupee Capital
cost(approximately)
6.5 crore rupee
Unit gain of electricity generation per year:1.9-1.6=300,000
Power purchase agreement rate(assumption):6.5 rupee per unit
Extra profit for installation of single axis tracker:300,000×6.5=19.5 Lac rupee per annum
Additional investment:6.5-6= 0.5 crore rupee = 50 lack rupee
Period back of money:2.5 years
Increase in energy output over single axis tracker: (300000/1900000)*100=15.78 %
Extra investment over fixed PV:(50/650)*100= 7.69 %
Total increase in generation with respect to investment: 18.75-8.33= 8.02 % (10%)

29. Fixed tilt Single axis tracker
Capacity 1 MW capacity 1 MW
LCoE: ($949367.08/1900000*25)=0.0199 per
kwh
LCoE: ($1028481.01/1900000*25)=0.0216 per
kwh
LCoE(fix)-LCoE(single axis)=0.0216-0.0199=$ 0.0017 per kwh
Reduction of LCoE: (0.0017/0.0216)×100 = 7.87 % (8 %)
Levelized cost of Energy for Scorpius Tracker
Levelized Cost = Net Cost to install a renewable energy system divided
by its expected life-time energy output.

30. Conclusion
 On one hand we can see the worlds energy resources depletion
to be a major problem.
 On the other hand global warming, which is a major concern.
 Switching to solar power, which is clean and green and
enhancing its efficiency by using sun trackers is a great option
in the near future .

31. Thank You