Solar Tracker with Actuator (12v Linear actuator)

With calls to take care of the environment intensifying, solar energy has become popular, and governments all over the world are trying to tap into this free energy. Solar energy is not only free and renewable but also comes with other benefits to both people and the environment.

According to the National Renewable Energy Laboratory, the sunlight received in the earth in just an hour is supposedly enough to meet the energy needs of everyone in the world for a year. The above is quite intriguing and shows that if man can tap into this glaring opportunity, he can benefit greatly and even move on from the depleting fossil fuel energy. According to the World Wide Fund for Nature, fossil fuel energy leads to the pollution of air, land, and water. Currently, the world is spending billions of dollars to help clean the environment and to create awareness.

solar panels

Unlike fossil fuel and nuclear energy, solar energy is safe and clean. Additionally, it helps to prevent the destruction of habitats while also combating climate change. The importance of solar energy is simply not in its cheapness and reliability but in the fact that it helps to preserve man’s home. With industries already sensitized, it remains to be seen whether the world will make a permanent shift. Early indications suggest that people are already warming up to the idea of shifting with Bloomberg reporting a 33% growth in the solar energy sector.

What is a Solar Tracker

Solar trackers are gaining in popularity all around the world. A simple explanation is a device used to incline the solar panels in the direction of sunlight. Solar trackers, therefore, follow the sun the entire day and ensure the solar panels capture or gather as much energy as possible. Their sole purpose is simply to maximize output.

The good news here is you can make your solar tracker at home. With the right kind of tools, most importantly solar panels and linear actuators, you can create your solar tracker and ensure your solar panels are capturing the maximum amount of sunlight.

How to Convert Solar Energy Into Electricity

Solar energy is without a doubt the cleanest form of energy currently in use. It is the result of sunlight being converted into electricity by solar panels which are usually placed on rooftops.

Solar energy is converted into electricity when sunlight strikes the solar-powered photovoltaic panels which are normally fitted with a silicon semiconductor. Once photons of light strike the silicon cells, electrons flow hence creating electricity. On most occasions, systems generating solar power usually take advantage of the above phenomenon to convert sunlight directly into electricity. Solar panels, for example, typically produce direct current which is then taken through a power inverter to generate an alternating current or ready to use electricity which can even be used in households.

We would use 3 separate components for that task:
Sungold solar panel SGM-90W-18V, solar charge controller Genasun GV-10 and 12VDC Lithium-Ion Battery.

sun tracker circuit diagram

Sun Tracker Circuit

Benefits of Using Linear Actuators in Solar Tracking System

While making your solar tracking system, it is indeed advisable and beneficial to use the 12v linear actuators. 12v actuators are preferred for solar tracker because they help to ensure or enhance the effectiveness of the solar panels. Therefore, while looking for an actuator for solar tracking system, always consider the 12v solar tracker actuator.

One of the main benefits of the 12v actuator is that it achieves the desired movements with higher precision. Therefore, regardless of the sun’s position, these actuators will ensure your solar panels are slanted or inclined in the best position possible to enhance their effectiveness in capturing sunlight.

Parts Needed for Solar Tracker

diy solar tracker using arduino and actuator

DIY Solar Tracker

  • PA-14 mini-linear actuator – 6 inch – 150 lbs force (There is also a possible option to make solar tracker using 330lbs linear actuator)
  • 12VDC Lithium Rechargeable Battery
  • Genasun GV-10 12VDC Solar Panel Charge Controller
  • Sungold SGM-90W-18 90 Watt Solar Panel
  • Arduino Micro PLC
  • solar tracker arduino

    Arduino Micro

  • Wasp Motor Controller
  • Wasp Motor Controller

    Wasp Motor Controller

  • Cigarette lighter connector for 12V accessories (optional)
  • 10k Ohm Photoresistor and 2x 7k Ohm Resistor (x2)

Sun Sensor

Sun sensors sense the direction to the sun for purposes of measuring the sun’s position relative to the sensor’s position. Here the 10k Ohm photoresistor will come in handy to help in detecting the light intensity as received from the sun. To help determine the precise position of the sun, two sensors will be needed (one on the east side and other on the west side).

Linear Actuator Controller

To ensure the solar panel changes its position with the changing position of the sun, the linear actuator needs to be controlled, and this is done using the PWM. To control the linear actuator, you have to set a value for PWM which then enables the actuator for solar tracker to extend, stop, or even retract for a period of time. The magnitude of the movement is determined by the readings received from the sensors.

Motor Controller Circuit

Motor Controller Circuit

SEE ALSO: How to Control a Linear Actuator with Arduino

Programming and Code Part

The full source code will be provided at the end of the article. This section will only explain the different parts included in the program.

  1. Servo Library – this library is important because it is responsible for enabling the Arduino Micro to control or regulate the RC servo motors;
  2. Pin Assignments – pin assignments are as follows: pin 10 and 11 are to set to drive the WASP controller and are hence set to power and ground. Pin 6 and 8 are assigned to analog 7 and 8 which is to take or record readings from the light sensors;
  3. Variable Declaration – this involves the declaration and initiation of variables. These will be used to store light sensor readings in the functions. Aside from these, the adjustment interval and sample time should also be declared here;
  4. Set Input and Output – remember always to Set WASP_Power and WASP_Ground to output. This is done to help drive the WASP controller. Set sensor_east_pin2 and sensor_west_pin1 to record the readings from the light sensors;
  5. Sensor Readings – in this project, two photoresistors are used as light sensors and depending on your program, these are supposed to take sample readings after a certain duration of time. For purposes of this article, the program takes 10 samples after every 10 seconds and then finds the average. A comparison of the two photoresistors is then done;
  6. Solar Panel Movement – to drive or control the actuator, you can use PWM. You can either extend, retract, or even stop the actuator but all of this is dependent on the value you set on the PWM. After averaging the value from the two light sensors, the solar tracker linear actuator then retracts or chooses to remain stationary based on the difference in the sensors’ reading. For this particular solar tracker, the commands will be initiating change every 10 minutes and the solar linear actuator will make the necessary adjustments to position the panels for maximum sunlight;
  7. Overnight Position Reset – after setting everything, it is indeed essential to implement the reset function. Every morning, the solar tracker needs to reposition itself, and this means that you have to include a function that helps with this functionality.

Program Instructions

solar tracker source code


The truth is solar energy will indeed replace fossil fuel energy in the near future. With people already coming with ways of increasing the effectiveness of solar panels, it remains to be seen what the future holds for the energy industry.

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