In a world increasingly attuned to the urgency of sustainable energy solutions, the spotlight has turned fervently towards the solar energy systems. Solar power, a beacon of clean and renewable energy, is undergoing a transformative evolution, and at the heart of this revolution lies the intriguing concept of solar tracking systems. Imagine a solar panel that not only captures sunlight but actively follows the sun's trajectory across the sky, optimizing energy absorption throughout the day.

In this article, we seek to unravel the concept of solar tracking systems by designing and implementing a dual axis solar tracking systems, exploring their potential to redefine how we tap into the boundless power of the sun. From the nuts and bolts of mechanical components to the futuristic applications of machine learning, we'll journey through the nuances of solar tracking, shedding light on its importance, challenges, and real-world impact.

What is a solar energy system?

A solar energy system is a technology designed to capture and convert sunlight into usable energy, offering a sustainable and environmentally friendly alternative to conventional energy sources. The two primary types of solar energy systems are photovoltaic (PV) systems, which directly convert sunlight into electricity through solar cells, and solar thermal systems, which harness sunlight to generate heat for applications such as space or water heating. Photovoltaic systems utilize solar panels to produce electricity, while solar thermal systems employ collectors to capture and transfer solar heat to a medium for various uses. Embraced across residential, commercial, and industrial sectors, solar energy systems play a crucial role in reducing dependence on fossil fuels, curbing greenhouse gas emissions, and fostering a cleaner and more sustainable energy future.

Why Solar Tracking?

While there are technologies like MPPT that have delved  towards solving the problem of energy maximization, there is still a need to for the problem of maximum sunlight exposure. 

As per information from the National Aeronautics and Space Administration (NASA), the Earth is exposed to an estimated 342 watts of solar energy per square meter. This substantial amount translates to an annual average of an impressive 44 quadrillion (4.4 x 10¹⁶) watts of electricity. To put this in perspective, a large-scale electrical plant typically produces around one billion (1 x 10⁹) watts of power.

To capture all this energy at maximum, there's a need for a tracking system that can track the part of the sunlight throughout the day, thereby positioning the panels at a direction perpendicular to the axis of the sun. 

Design of the device:

The device is designed using a CAD software (TinkerCAD). The design encompasses a mechanical design, electrical design and control mechanism. 

Mechanical design:

The mechanical design serves as the foundational structure for the entire setup, accommodating crucial elements such as the solar panel, motors, and the intricate network of circuit components and wires essential for the successful realization of the project.

The meticulous execution of the mechanical design holds paramount significance, given that the functionality of every other component within the system hinges upon it. The initial phase of the mechanical design involved utilizing Computer-Aided Design (CAD) software, specifically TinkerCAD, to create a detailed model. Subsequently, with the expertise of a skilled welder engineer, The digital design was then translated into a tangible and rubust structure, forming the backbone of the tracking system To render the model in 3D click here.

Mechanical design Materials

1. Square pipe (20 x 20mm)
2. Ball bearing (19mm inner diameter)
3. Steel sheet
4. Flat bar
5. Bolts, nuts and washers (19mm, 13mm, 6mm, 4mm etc).
6. 6mm to 19mm shaft coupler

Structural Setup

Electrical design:

The electrical design for this system is focused on implementing a control system to optimize the orientation of solar panels for maximum energy tracking efficiency. Central to this endeavor are light sensors, particularly Light-Dependent Resistors (LDRs). The sensor data is then transmitted to a microcontroller, which processes the signals and subsequently commands the motors to reposition the photovoltaic (PV) array.

This orchestrated movement occurs in two axes, allowing the solar panels to dynamically follow the sun's apparent motion in both azimuth and elevation. Through this synchronized interaction between sensors, microcontroller, and motors, the electrical design plays a pivotal role in ensuring the precise and adaptive alignment of the solar tracking system for optimal energy absorption. To view and simulate the electrical design of the setup, click here.

Electrical Design Materials

1. Battery 12V 7ah
2. Display unit
3. I2c for display unit
4. Jumper wires
5. 2.5mm wires
6. Breadboard
7. Push buttons
8. Toggle Switch
9. Dual H-bridge driver IC
10. 12V geared Dc motors 6mm diameter
11. Resistors (10k ohms)
12. Arduino Uno Micro controller
13. LDR
14. Solar panel (20W)

Tracking Mechanism. 

When sunlight, acting as the primary light source, illuminates both the PV module and the Light Dependent Resistor (LDR), the PV module supplies power to the microcontroller circuit, providing a direct current (dc) voltage of approximately 12V. The LDR then transmits its input to the microcontroller, which subsequently undergoes processing. Following the processing of the LDR's signal, the microcontroller activates the actuation motors in proportion to the input received from each of the four LDRs.

The tracking mechanism is illustrated in the block diagram as shown below. 

   Flow chart   

In cases where the PV module is not correctly oriented, causing the incident light to strike at an angle other than 90 degrees, the motor is set into motion to readjust the position of the PV module. These procedures are iterated whenever there are alterations in the orientation of the light source, whether it be sunlight or any other light source.

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