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How can you get as much power as possible out of a solar panel, even in the morning or evening when the sun is low in the sky? With a solar tracker system! While many solar panels are fixed in place on rooftops or large ground-mounted poles, a solar tracker system is motorized and lets the solar panels track the sun through the sky during the day. Are these systems worth the added complexity? How much more power do they produce? Try this project and find out!
AREAS OF SCIENCE
Energy & Power
Electricity & Electronics


Solar power is a form of renewable energy that converts sunlight into electricity using solar panels (Figure 1). Solar panels can be mounted on rooftops or on the ground. They can even be mixed into agricultural spaces for livestock or crops using a technique called agrivoltaics (Figure 2).
solar-array-rooftop

Figure 1. An array of solar panels on a rooftop.

sheep-agrivoltaics

Figure 2. Sheep grazing under solar panels.

The amount of electrical power produced by a solar panel depends on the amount of sunlight hitting it. A solar panel will produce maximum power when it is perpendicular to the sun's rays (Figure 3). The sun moves east to west through the sky during the day, so solar panels will produce less power in the morning and evening when the sun is lower in the sky. The sun's position in the sky also changes from north to south throughout the year. Fixed solar panels, like those in Figures 1 and 2, are oriented to maximize the total amount of power that they produce throughout the year. These systems have the advantage of being simple and low-maintenance because they have no moving parts, but they do not produce the maximum possible amount of power.

solar-panel-angle-diagram
Figure 3. Side view of a solar panel showing how it will produce maximum power when it is perpendicular to the sun's rays.

Solar trackers (Figure 4) are an alternative to fixed-mount systems. These trackers are motorized and move the panels to keep them pointed directly at the sun. Single-axis trackers have a single axis of rotation, usually to track the sun's east-west movement. Dual-axis trackers have two axes of rotation, so they can also track the sun's seasonal north-south movement. These systems will produce more power for a given solar panel size but are more complex and require maintenance since they have moving parts.

solar-tracker
Figure 4. A solar tracker system.

In this project, you will design and build your own solar tracker system. The tracker will use two light sensors, called photoresistors, to track the sun. When both sensors are pointed directly at the sun, they will give equal readings, and the servo motor that aims the solar panel will not move. When one sensor is shaded, the motor will rotate until they both give equal readings again. You will also measure the performance of your tracker. One way to do this is to measure the voltage produced by your solar panel. The voltage will be higher when the panel is perpendicular to the sun's rays. You can track how the voltage changes throughout the day for a fixed-mount system and for your tracking system. Do you think the extra complexity of the tracking system is worth it? Try this project and find out!

  • Solar power
  • Renewable energy
  • Solar panel
  • Agrivoltaics
  • Solar tracker
  • Single-axis
  • Dual-axis
  • Light sensor
  • Photoresistor
  • Servo motor
  • Voltage


  • What are the different types of solar trackers?
  • What are some advantages and disadvantages of solar trackers?
  • What other factors affect a solar panel's output power?


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