This document describes the design of a solar tracking system using an 8051 microcontroller that automatically orients a solar panel to track the sun from east to west for maximum solar energy collection. The system uses a light dependent resistor to sense light intensity and signal a stepper motor controlled by the microcontroller to rotate the panel. It provides an affordable way to maximize solar panel efficiency through software algorithms that precisely position the panel without needing many sensors.

1. SOLAR TRACKING SYSTEM USING
8051 MICROCONTROLLER

2. THE SOLAR OPTION:
 Solar energy is a very large, inexhaustible source of energy. The power from the sun
intercepted by the earth is approximately 1.8*10^11 MW, which is many thousands of times
larger than the present consumption rate on the earth of all commercial energy sources.
 Solar energy could supply all the present and future energy needs of the world on a
continuing basis. This makes it one of the most promising of the unconventional energy
sources.
 It has two other factors in the favour:
i. Firstly, unlike fossil fuels and nuclear power, it is environmentally clean source of
energy.
ii.Secondly, it is free and available in adequate quantities in almost all parts of the world
where people live. Also it has no heavy mechanical section and is free from noise.
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3. OBJECTIVE
 The aim of this project is to utilize the maximum solar energy through solar panel. For this a digital
based automatic sun tracking system is proposed.
 The solar panel tracks the sun from east to west automatically for maximum intensity of light.
 Processes Involved are-:
i. To fabricate a Stepper motor control interfaced with driver circuit.
ii. To construct a model prototype solar cell movement system with a mechanical
assembly to move the panel from 180⁰ E to W.
iii.To design an electronic circuit to sense the intensity of light and to control stepper
motor driver for the panel movement.
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4. How the tracker follows the Sun:
1.Sunrise “Wake- Up”:
The Track Rack begins the day
facing west. As the morning
sun rises, the sun rays falls on
the LDR, it detects and sends
signal to stepper motor to turn
towards the east.
2. Mid-Morning:
As the sun rises, the LDR
also detect the angle, where
its getting maximum
efficiency and
correspondingly move
towards that direction.
3. Mid-Afternoon:
As the sun moves, the Track
Rack follows (at
approximately 15o per hour,
continually moving from one
side to another.
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.
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5. POWER SUPPLY:5
 The aim is to design the power supply section which converts 230V AC in to 5V DC.
 I short listed to use Bridge rectifier, because half wave rectifier has less efficiency. Even though the
efficiency of full wave and bridge rectifier are the same, there is no requirement for any negative voltage
for our application and thus bridge rectifier is incorporated.

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7. COMPONENTS USED:
 SOFTWARE : Assembly Language Programming
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COMPONENT SPECIFICATIONS
1. Microcontroller AT89S52.
2. Voltage regulator 7812,7805.
3. Driver ULN2003.
4. LDR,LCD ---
5. Stepper Motor 7.5 degree per step
6. Transformer TRAN-2P2S
7. Crystal Oscillator 11.0592 MHz
8. Resistors 100Ω.
9. Capacitor 33pF, 1000uF.
10. Rectifier W10

8. STEPPER MOTOR:
 It is a brushless synchronous motor.
 It can drive one rotation in many
steps.
 It has multiple “toothed”
electromagnets.

9. LIGHT DEPENDENT RESISTOR – LDR:
 Two cadmium sulphide (CdS)
photoconductive cells with spectral
responses similar to that of the
human eye.
 The cell resistance falls with
increasing light intensity.
 Applications include smoke
detection, automatic lighting control,
batch counting and burglar alarm
systems.
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10. POSITIVE VOLTAGE REGULATOR:
 Employs internal current limiting ,
thermal shut down and safe operating
area protection, making it essentially
indestructible
 Can deliver over 1A output current with
adequate heat sinking
 Can be used with external components
to obtain adjustable voltages and
currents
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11. SILICON BRIDGE RECTIFIER:
 Glass passivated chip
 High case dielectric strength
 High surge current capability
 High reliability
 Low reverse current
 Low forward voltage drop
 Ideal for printed circuit board
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12. AT89C52 MICROCONTROLLER:
 Low-power,
 High-performance
 CMOS 8-bit microcomputer with 8K bytes of
Flash programmable and erasable read only
memory (PEROM)
 Highly-flexible and cost-effective
 On-chip Flash allows the program memory
to be reprogrammed in-system or by a
conventional nonvolatile memory
programmer
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13. ECONOMICALLY AFFORDABLE:
 The attractive feature of the constructed prototype is the software solution of many
challenges regarding solar tracking system.
 The designed prototype requires only two photo resistors to sense the light, which
lessens the cost of the system.
 Power consumption of the system is negligible as ‘wait’ states are calculated perfectly
with the sun’s position.
 Another major problem of system initialization at the start of the day is solved through
a simple programming application. All these software based solution reduce the system
cost far more than all other systems proposed to date.
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14. CONCLUSION
 I presented a means of tracking the sun’s position with the help of microcontroller.
Specially, it demonstrates a working software solution for maximizing solar cell
output by positioning a solar panel at the point of maximum light intensity.
 Moreover, the tracker can initialize the starting position itself which reduce the
need of any more photo resistors.
 Though the prototype has limitations in hardware areas as an initial set up, still it
provides an opportunity for improvement of the design methodology in future.
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15. THANK YOU
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