Ms.Karishma Chawariya, Ms.Leena Naringe, Ms.Nikita Dongre, Mrs.Priyanka Paripagar
Department of ETC Engineering
Jhulelal Institute of Technology,
Lonara, Nagpur University, Nagpur, India.
E-mail id: karishmachawariya23@gmail.com
Contact No. 8983428563
Prof.Nilesh Dhanore
Assistant Professor
Department of ETC Engineering
Jhulelal Institute of Technology,
Lonara, Nagpur University, Nagpur, India.
Abstract-
This paper presents the hardware design and implementation of a system that ensure a perpendicular profile of the solar panel with the sun in order to extract maximum energy following on its renewable energy is rapidly gaining importance as an energy resource as fossil fuel prices fluctuate. The unique feature of the proposed system in that instead of taking the earth as it reference ,it take the sun as a guiding source its active sensor constantly monitors the sunlight and rotates the panel towards the direction where the intensity of sunlight is maximum.
Keyword– solar tracker
1. INTRODUCTION
Solar Panels are a form of active solar power, a term that describes how solar panels make use of the sun’s energy; solar panels harvest sunlight and actively convert it to electricity. Solar Cells, or photovoltaic cells, are arranged in a grid-like pattern on the surface of the solar panel. Solar panels are typically constructed with crystalline silicon, which is used in other industries ( such as the microprocessor industry ), and the more expensive gallium arsenide, which is produced exclusively for use in photovoltaic ( solar ) cells.
Solar panels collect solar radiation from the sun and actively convert that energy to electricity. Solar panels are comprised of several individual solar cells. These solar cells function similarly to large semiconductors and utilize a large area p-n junction diode. When the solar cells are exposed to sunlight, the p-n junction diodes convert the energy from sunlight into usable electrical energy. The energy generated from photons striking the surface of the solar panel allows electrons to be knocked out of their orbits and released, and electric fields in the solar cells pull these free electrons in a directional current, from which metal contacts in the solar cell can generate electricity. The more solar cells in a solar panel and the higher the quality of the solar cells, the more total electrical output the solar panel can produce. The conversion of sunlight to usable electrical energy has been dubbed the Photovoltaic Effect.
A solar tracker is a device that orients a payload toward the sun. The use of solar trackers can increase electricity production by around a third, and some claim by as much as 40% in some regions, compared with modules at a fixed angle. In any solar application, the conversion efficiency is improved when the modules are continually adjusted to the optimum angle as the sun traverses the sky. As improved efficiency means improved yield, use of trackers can make quite a difference to the income from a large plant.
Commercial purpose of solar tracking system:
- Increase Solar Panel Output.
- Maximum efficiency of the panel.
- Maximize Power per unit area.
- Able to grab the energy throughout the day.
2. SYSTEM OVERVIEW
2.1 Microcontroller
Microcontroller is a single chip micro computer made through VLSI fabrication. A microcontroller also called an embedded controller because the microcontroller and its support circuits are often built into, or embedded in, the devices they control. A microcontroller is available in different word lengths like microprocessors (4bit,8bit,16bit,32bit,64bit and 128 bit microcontrollers are available today).
A microcontroller contains one or more of the following components:
- Central processing unit (CPU)
- Random Access Memory (RAM)
- Read Only Memory (ROM)
- Input/Output ports
- Timers and Counters
- Interrupt controls
- Analog to digital converters
- Digital analog converters
- Serial interfacing ports
- Oscillatory circuits
2.2 LCD
LCD used here is 16 by 2. Following fig. shows the microcontroller and LCD interface.
LCD Pin Description:
LCD pin configuration is as follows
VCC, VSS, VEE
VCC & VSS provides +5V & ground respectively, VEE is used for adjusting LCD contrast.
Register Select
If RS = 0, the instruction command code register is selected, allowing the user to send a command such as clear display, cursor at home, etc. If RS = 1, data to be displayed on LCD.
R/W (Read/Write)
If R/W = 1, Read operation. If R/W = 0, Write operation. The LCD, to latch information presented to its data pins uses the enable pin. When data is supplied to data pins, a high to low pulse must be applied to this pin in order to latch data present at the data pins. The pulse must be a minimum of 450ns wide. D0-D7 is used to send information to the LCD or read the contents of the LCD’s internal registers. To display letters and numbers, ASCII codes are sent for the letters A-Z, a-z and numbers 0-9 to these pins while making RS=1. There are also instruction command codes that can be sent to the LCD to clear the display or force the cursor to the home position or blink the cursor. We also use RS = 0 to check the busy flag bit. When D7 = 1, the LCD is busy in taking care of the internal operation, will not accept any new information. When D7 = 0, the LCD is ready to receive new data.
2.3 RELAY
The relay is electromechanical. The voltage required is +12V DC. It can be obtained using the relay driver IC. When the relay is excited by applying the 12V DC, the relay gets activated, turns ON the device and when the excited voltage is stopped, the relay gets deactivated and turns OFF the device.
3.Operation of the Solar Tracker
Solar tracker provides three ways of operation and control mechanism through the programme written in microcontroller.
A. Normal day light condition: – Two photo resistors are used in the solar tracker to compare the output voltages from two junctions. As the sun rotates from east to west in the day time, AIN0 needs to provide higher voltage than AIN1 to sense the rotation of the sun. This condition is considered as normal day light condition and tracker rotates the panel 3.75° after every 15 minutes.
B. Bad weather condition: – When the sky gets cloudy, there will be less striking of light on both the photo resistors and so sufficient voltages might not be available at junction point. The difference of voltage at junction point will not be greater than the threshold value to rotate the tracker. At the meantime, sun continues rotating in the western direction. To solve this problem, a short delay is provided which will check for voltage input from junction point in every 1.5 minutes. Microcontroller will use the variable Count to check for consecutively 10 times to make the ‘wait’ state equal to 15 minutes (moderate delay) to rotate the stepper motor one step.
C. Bidirectional rotation: – At day time, the solar tracker will rotate in only one direction from east to west. Variable I will count the total rotation in day time and that is approximately calculated as 40 rotations considering 150° rotation. When the sun sets, no more rotation is needed in western direction. For the next day, the solar panel needs to go to the initial position in the morning to track the sun’s position again. To do so, the variable I that counts the number of rotation in the day time will work out. When the variable (I) shows value greater than 40, the tracker stops rotating in the western direction and rotates reversely in the eastern direction to set the tracker to the initial position for the next day. When it goes to initial position, power supply to the tracker will be turned off and the tracker will be in stand by till sunlight in the next morning.
4.Conclusion and Future Scope
As the proposed prototype is a miniature of main system, it has some limitations which can be mitigated through future developments. A small cardboard is rotated in the system and 12v solar panel is used for analysis. As a miniature system, it works out well. Larger Solar panel must be integrated with the system to prepare better result and cost analysis. It has been proven through our research and statistical analysis that solar tracking system with single-axis freedom can increase energy output by approximately 20%
References
- Digital Electronics And Microprocessors – R.P.Jain – Mc. Graw Hill Education.
- IEEE paper-: Stepper Motor Drives for Robotic Applications- Benetta Aranjo, Prashant Kumar Soori, and Puja Talukder.
- S. Rahman, “Green power: what is it and where can we find it?” IEEE Power and Energy Magazine, vol. 1, no. 1, pp. 30-37, 2003.
