MAXIMUM SOLAR ABSORPTION USING DUAL AXIS SOLAR PANEL

Introduction

Solar panels are devices that convert light into electricity. They are called solar after the sun because the sun is the most powerful source of the light available for use. They are sometimes called photovoltaic which means "light-electricity".

A Solar Tracker is a device onto which solar panels are fitted which tracks the motion of the sun across the sky ensuring that the maximum amount of sunlight strikes the panels throughout the day.

The Solar Tracker will attempt to navigate to the best angle of exposure of light from the sun.

Synopsis

• OBJECTIVE:

• The main aim of our project is to track the maximum solar energy without radiation loss for the efficient use of solar energy, and logging data (voltage, current).

• The problem with the existing system is stationery solar panels cannot track maximum radiations hence most of energy is wasted.

• What we expect through logging the data is that before a user buys any solar panel and is expecting it to work at the given rated voltage or current, he or she can check the validity of that rating on the apparatus used for solar tracking by our project.

• In order to overcome this, our project aims at implementing rotatory solar panel using microcontrollers which will rotate by sensing the intensity of the radiation and logs the data(voltage and current) for testing the capacity of the solar panel.

Literature Survey Types of Solar Trackers:

Single Axis Tracker Dual Axis Tracker

STRUCTURAL DIAGRAM

HARDWARE DESCRIPTION Defined as a bank of Solar cells Solar Panel

• 60 watts solar panel• 20 volts x 3 amperes

A photo-resistor or light-dependent resistor is a light-controlled variable resistor. Light Dependent Resistors• The resistance of a photo-resistor decreases with increasing incident light intensity;• It exhibits photoconductivity.

It is a brushless DC electric motor that divides a full rotation into a number of equal steps.Stepper Motor• With a drive voltage of 12 to 24 volts.• Current setting of 2.5 amps

Batteries are device which are used for storing chemical energy in form of electrical energy. Battery• Using a nominal battery of 40 amp hour with maximum charging current of 12 amps.

A charge controller has an essential purpose to keep your batteries properly fed and safe for the long term.Charge Controller

• Battery voltage of 12 volts• Easy installation, LED indicator

Device that detects electric current (AC or DC) in a wire, and generates a signal proportional to it.Current Sensor

• Using ACS 712 current sensor provided in a small, surface mount package, 5.0 V single supply operation 

A gearbox is a collection of mechanical components that deliver maximum strength by managing a series of gear ratios that in turn operate a transmission.Gear Box

• We are using a gear box of gear ratio 1:14.33, it means that for every one revolution of the pinion, gear has made 0.433 revolutions.

PROGRAMMER’S CONSIDERATIONS√ Using ARDUINO MEGA 2560

microcontroller. Having 54 digital input/output

pins. 16 analog inputs 256 KB flash memory Each pin can provide max of

40mA

√ With ARDUINO as the programming language

Arduino Breakout Board A project with any audio, video, graphics,

data logging, etc in it, you'll find that having a removable storage option is essential.

They are strictly 3.3V devices and the power draw when writing to the card can be fairly high, up to 100mA.

Arduino mega uses digital pins as 50 (MISO), 51 (MOSI), 52 (SCK), and for the CS line, the most common pin is 53 (SS).

Design for Voltage Divider Voltage divider circuit is used as a voltage

sensor. The maximum voltage extracted from the solar panel is 20V.

But the arduino microcontroller board is devised for working on atmost 5 V therefore using a voltage divider circuit to protect the board circuitry.

Therefore it is designed as, Vo= (Vin x R2)/(R1+R2) Given Vinmax = 20 Volts Vomax= 5 Volts Assume R2=1.5KΩ Therefore R1= 4.55KΩ

Testing Procedures

• Solar panel testing is done by checking its output voltage and current. by connecting the solar panel output to the charge controller and the values for voltage and current at different times of the day for the rotating and static solar panel is tabulated

Solar Panel:

• The battery is tested by checking it’s charging and discharging time. Connecting the battery to a high current consuming load like a charger may reduce its discharging time.

Battery Testing:

• Stepper motor is tested by energizing the motor coils and by giving clock pulses for a particular period of time to the motor driver.

Motor Testing:

• The sensors were tested for proper measurement of voltage and current through ammeters and voltmeters around the load resistors.

Sensor Testing:

• The LDRs are mounted on the panel based on the sensor ouput panel rotated either in CW or CCW direction throughout the day to duly test the limitations of the assembly.

Solar Tracker Assembly Testing:

WORKING MODEL

Stepper motor is used for EAST to WEST rotation of the solar panel on the daily basis.

For the NORTH to SOUTH axis rotation manual handling is advised.

Results

Results (contd.)

Future Scope

Fabrication of Microcontroller using ASIC concepts: The number of wires can be greatly reduced by directly if a customized PCB is made upon which all the resistors can be directly soldered. This also eliminates the use of a Breadboard which was used to make all the external connections.

Mounting of the Panels: In our design, the panels are mounted on a horizontal shaft supported strongly at both ends. We can mount the panels directly onto a motor placed at the center of the Panel-Base in order to provide East-West movement. This reduces the weight and effective cost of the project.

APPLICATIONS

Main Applications can be enumerated as: Alternative power source

As the solar apparatus charges the battery during its ON time thus that can be used as a secondary power source.

Used as a measuring instrument for other solar panels For this application it is needed to store data in

memory, using arduino we have done it to micro-sd card which anyone can check on their smartphones.

Using the same apparatus for measuring the extent of efficiency for a solar panel will be much cost effective for the newbies in this area of power. TIME

VOLTAGE(vol

ts)

CURRENT(amps)

7.15 am 12.71 0.42 7.30 am 13.03 0.72 7.45 am 13.15 1.09 8.00 am 13.28 1.43 8.15 am 13.59 1.80 8.30 am 13.63 1.80 9.00 am 14.65 1.83 9.20 am 15.5 2.03 9.40 am 17.6 2.1 10.00 am 18 2.15 10.15 am 18.5 2.19

10.45 am 18.7 2.3

11.15 am 18.9 2.49 11.50 am 19.0 2.51 12.30 pm 19.0 2.53

CONCLUSION

MERITS

Clean and green source of power.

Solar panels are reasonably easy, safe and convenient to install.

One time investment which provides higher efficiency and reliability.

Solar Tracking systems continually orient PV panels towards the sun and can help maximize the investment on PV system.

DEMERITS

Initial investment is high.

Moving parts such as gears needs periodic maintenance.

Maintenance and repairing of mechanical and electronic parts of the tracking system requires extra man-power and of extra investment.

Has to be built extreme environmental conditions such as storms, heavy rainfall etc.