A Detailed Guide on Solar Trackers

A solar tracker is a mechanical system that automatically adjusts the position of solar panels. It makes the panels rotate in such a way that these panels face the sun directly, rather than staying locked in one position. 

This results in higher solar energy capture compared to fixed mount system. 

Why does this matter? Physics. When sunlight hits a solar panel straight-on at a 90-degree angle, you get maximum power generation. When the light hits at a shallow angle, you lose efficiency. 

Solar trackers are commonly used in large commercial and utility-scale solar power plants, where even a small increase in efficiency can translate into significant gains in energy production and revenue.

Why Do Solar Trackers Matter?

Sunlight hits a solar panel most effectively when the rays strike it at a right angle. As this angle changes during the day, fixed panels lose some potential output.

Solar trackers solve this problem by:

• Increasing daily energy generation
• Improving performance during early mornings and late evenings
• Making better use of available land

Depending on the type and location, solar trackers can increase electricity generation by 10% to 60% compared to fixed systems.

How Do Solar Trackers Work?

Every tracking system has three basic parts working together.

First, you need sensors that figure out where the sun is. Some trackers use light sensors, basically fancy versions of those automatic lights that turn on at dusk. Others use GPS and astronomical calculations to predict the sun’s position without needing to “see” it. The GPS approach is actually pretty clever because clouds and weather don’t throw it off.

Then there’s a controller, which is just a small computer doing math. It takes the sensor data and calculates which way the panels should point. This happens every few minutes throughout the day.

Finally, motors and actuators do the actual moving. These need to be strong enough to handle wind loads and the weight of multiple panels while still being precise enough to make small adjustments. 

The whole system runs on a tiny fraction of the extra power it generates, maybe 1-2% of the energy boost. The rest is pure gain.

There’s also something called passive trackers that use thermal expansion instead of motors. Solar heat causes gas in special tubes to expand, which moves the panels.

Types of Solar Trackers Based on Axis of Movement

Solar trackers can be classified in two ways – by movement axis and operating mechanism. 

• Single Axis Solar Trackers

Single-axis trackers rotate solar panels along one axis, usually from east to west. They follow the sun’s daily path across the sky but do not adjust for daily changes in the sun’s height. Even with limited movement, single-axis trackers can still capture a substantial amount of sunlight compared to fixed panels. 

These panels are widely used in commercial and large solar farms. Single axis panel deliver a good energy output but require more land spacing than fixed systems. 

• Dual Axis Solar Trackers

Dual-axis solar trackers take it a step further. They move along two axes – east-west and north-south. These trackers track both daily and seasonal movement of the sun, keeping panels optimally aligned all year round. 

This precision makes them the most efficient type of solar tracker available. However, these trackers are costly in installation and equally expensive in terms of maintenance. These panels are more commonly found in research projects, and concentrated solar power systems, where output is the priority. 

Types of Solar Trackers Based on Operating Mechanism

• Active Solar Trackers

Active solar trackers use motors, controllers, and sensors to determine the sun’s position and move panels accordingly. These systems may use light sensors, GPS data, or pre-programmed solar paths to guide movement.The biggest advantage of active trackers is precision. They are highly responsive and can make frequent adjustments to keep panels optimally aligned even under changing weather conditions. Require frequent maintenance and can be expensive to install. 

• Passive Solar Trackers

Passive solar trackers operate on a different principle. Instead of using electrical motors, they rely on thermal expansion or fluid movement caused by sunlight. These trackers do not require external power to operate. They offer less control, respond slowly and often struggle in inconsistent weather conditions. Hence, these trackers are only used in small or experimental systems and not large scale solar installations. 

Also read: Types of Solar Power Plants Explained: On-Grid, Off-Grid & hybrid

Advantages of Solar Trackers

• Improved Land Utilization

There’s also a land efficiency angle. If you’re working with limited space, maybe a commercial property that can only dedicate a certain area to solar, trackers let you generate more power from the same footprint. In urban or high-value land situations, that can make or break a project’s economics.

• Better Performance During Non-Peak Hours

Trackers produce significantly more energy in the early morning and late evening when fixed panels are barely contributing. If you’re selling power back to the grid, those shoulder hours can command higher prices in some markets. That early evening production lines up perfectly with peak demand when everyone gets home from work.

• Faster Payback for Large Projects

For commercial and utility-scale installations, the additional energy generated can improve project economics over time. Yes, you’re paying more upfront, but the increased production can shorten your payback period by years. Money now versus money later, it’s a calculation every business understands.

Limitations of Using Solar Trackers

• High Maintenance

Moving parts break. Motors fail. Sensors get knocked out of alignment. Gearboxes wear down. None of this is catastrophic, but it means you need an actual maintenance program with trained technicians who know what they’re doing. On the contrary, a fixed solar residential solar panel system only needs regular cleaning and maintenance, nothing else. 

• Mechanical Wear and Tear

Over time, components are exposed to wind, dust, and weather, which can impact reliability if not maintained well. Solar trackers are built tough but they are not completely indestructible. 

• Not Ideal for All Locations

Solar trackers work best in places with clear, direct sunlight. In regions with frequent cloud cover or low solar radiation, the additional cost may not justify the energy gains.

Conclusion

Solar trackers are definitely a smarter evolution in solar technology. By allowing panels to follow the sun instead of staying fixed, they unlock better performance throughout the day. These trackers may not be the right choice for every situation. But when conditions align – good sun, adequate space, proper budget, they’re one of the most effective ways to maximize solar energy production.

The technology has matured considerably over the past decade. Modern trackers are more reliable, more affordable, and easier to maintain than earlier generations.