What is a Solar Tracker?

A solar tracker is a mechanical and control system that enables photovoltaic (PV) modules to adjust their tilt or orientation automatically in response to the sun’s position. Its primary function is to maintain an optimal incident angle between sunlight and the PV module, thereby maximizing solar radiation capture. Compared with fix-mounted structures, a well-designed solar tracking system can deliver a substantial increase in annual energy yield—typically in the range of 15% to 45% depending on project latitude, climatic conditions, and tracker type.

Why Solar Trackers are Deployed

The instantaneous output of a PV module is highly dependent on the angle of incidence. Maximum power output occurs when sunlight strikes the module perpendicularly. However, the sun’s azimuth changes continuously during the day, and its elevation varies with the seasons, meaning fixed-tilt arrays operate at a suboptimal angle for much of the year.

A solar tracker can effectively follow either the sun’s azimuth or elevation angle. Overall, this can deliver an energy gain of approximately 15%–45%, which is the main reason we choose solar trackers. Moreover, for projects with high electricity prices or scarce land resources—such as off-grid plants or PV-plus-BESS systems—designers often require the system to generate as much electricity as possible to meet demand. As a result, the use of solar trackers is often considered during the project planning stage to achieve these targets.

Types of Solar Trackers and Application Profiles

In commercial PV deployments, three tracker configurations are most prevalent: vertical single-axis, horizontal single-axis, and dual-axis.

Vertical single-axis solar trackers rotate around an axis perpendicular to the ground, tracking the sun’s azimuth. This design minimizes inter-row shading, provides accurate east–west tracking, and offers mechanical robustness with good adaptability to irregular terrain. It is widely deployed in mid- to high-latitude regions such as North America and parts of Europe. Under favorable irradiance and terrain conditions, vertical single-axis systems typically deliver an annual energy gain of 20%–35% over fixed-tilt systems.

Horizontal single-axis trackers have a rotation axis parallel to the ground, typically oriented north–south. The PV modules pivot to track the sun’s daily azimuthal movement. This configuration performs optimally in low- to mid-latitude regions with flat terrain and is the dominant choice for large-scale, ground-mounted PV plants. Standardized manufacturing, mature control systems, and proven O&M practices make it a cost-effective option, with annual yield gains generally in the range of 15%–25%.

Dual-axis trackers can rotate in both azimuth and elevation, enabling precise alignment with the sun’s position year-round. This configuration achieves the highest possible solar capture efficiency, with typical energy gains of 20%–45%, and is often used in off-grid, high-value, or space-constrained distributed generation projects. However, higher costs, increased O&M complexity, and vulnerability to high wind or snow loading limit their adoption in large-scale utility projects.

Key Components of a Solar Tracking System

A solar tracker generally consists of the following components:

**Structural support:**Posts, beams, and purlins that secure PV modules and bear environmental loads such as wind and snow.

**Control system: **Controllers, sensors, and GPS units that compute solar position and issue actuation commands.

**Drive system:**Electric linear actuators or motors that provide movement.

**Transmission system:**Bearings, linkages, and gearboxes that transfer motion to the moving structure.

Additionally, the foundation anchors the tracker to the ground. Devices such as wind speed sensors and limit switches help ensure stable operation, and in high-wind conditions, they can adjust the system to a safe stow position.

Common Issues in Projects

As installed capacity increases, projects may face certain challenges. For example, some projects meet the design wind speed requirements but still experience module damage due to wind-induced vibration or vortex shedding. Poorly designed multi-row drive systems may suffer from synchronization issues, leading to uneven mechanical stress on the modules. Sensor failures or GPS signal interference can cause angular misalignment, reducing energy yield. In areas with soft soil, uneven settlement may result in deformation or jamming of the rotation axis. A lack of regular inspection and maintenance can shorten the service life of drive and transmission components.

Emerging Trends in Solar Tracker Technology

Recent development trends center on intelligence, reliability, and cost optimization. AI-enabled control systems integrated with weather forecasting can preemptively adjust stow and tilt positions based on predicted cloud cover and wind loads, minimizing both shading losses and structural stress. The co-location of battery storage with solar trackers is gaining traction, enabling smoother generation profiles. Low-maintenance designs—such as sealed, lubrication-free bearings and IP-rated drive motors—are increasingly standard, as is automated high-wind stow functionality. Lightweight, modular designs are reducing transportation and installation costs, accelerating project deployment—especially in international EPC markets.

As technology matures and levelized cost of energy (LCOE) metrics improve, solar trackers are being adopted not only in utility-scale ground-mounted plants but also in distributed generation and off-grid applications. For a growing share of PV projects, a solar tracking system is now considered a core component of the plant’s performance strategy.