How Does a Solar Tracker Work?

How Does a Solar Tracker Work? Types, Costs & Energy Gains

A solar tracker is a motorized mounting system that rotates solar panels to follow the sun as it moves across the sky. Instead of staying fixed at a single angle, the panels continuously adjust their position — keeping them pointed directly at the sun from morning to evening.

The result: 25–30% more electricity from the same number of panels compared to a fixed-tilt installation.

This guide covers exactly how solar trackers work, the difference between single-axis and dual-axis systems, real-world energy gains, costs, and how to decide which type fits your project.

How a Solar Tracker Works: The Basic Mechanism

Every solar tracker has three core elements working together:

1. Sensors Photoelectric sensors measure sunlight intensity from multiple angles in real time. When the sensor detects that the sun has moved, it sends a signal to the controller.

2. Controller The controller processes sensor data (or uses a pre-programmed astronomical algorithm based on GPS coordinates and time) to calculate the optimal panel angle. Modern systems use both methods together — the algorithm sets the base position, and sensors fine-tune it.

3. Actuators and Drive Motors Linear or rotary actuators physically move the mounting structure. A single-axis tracker uses one motor; a dual-axis uses two. The motors are typically low-power (a few hundred watts for an entire row of panels), so the energy used for tracking is a tiny fraction of the extra energy gained.

The entire cycle — sense, calculate, move — repeats continuously throughout the day, keeping panels within a few degrees of perpendicular to the sun at all times.

Single-Axis vs. Dual-Axis Trackers: What's the Difference?

Single-Axis Trackers (HSAT)

The most widely deployed tracker type globally. The mounting structure rotates on a single horizontal axis oriented north–south, allowing panels to sweep from east to west throughout the day.

Why most large solar farms choose single-axis:

• Energy gain of 15–25% over fixed is substantial and predictable
• Simpler mechanics mean lower maintenance cost
• Rows can be spaced efficiently, minimizing land use impact
• Proven at GW scale — bankable technology for project finance

A standard single-axis tracker row typically covers 60–80 panels on a single torque tube, driven by one gearbox motor. Stow positions (panels laid flat) protect the system during high winds.

Dual-Axis Trackers

Dual-axis trackers add a second axis of rotation, allowing panels to also tilt north–south to compensate for the sun's seasonal altitude changes. This achieves near-perfect alignment with the sun at all times.

When dual-axis makes sense:

• Concentrated photovoltaic (CPV) systems that require precise alignment
• Sites above 50° latitude where seasonal sun angle variation is extreme
• Smaller installations where maximum yield per panel justifies higher cost

For most utility-scale PV projects, the additional energy gain of dual-axis over single-axis (typically 5–10 percentage points) does not justify the significantly higher cost and maintenance complexity. Single-axis dominates at scale for this reason.

Real-World Energy Gains: What to Expect

Energy gain depends heavily on geographic location — specifically, how much the sun's angle varies throughout the day and year at your site.

Note: Actual gains vary by local climate, row spacing, and shading conditions.

The highest gains occur in clear-sky, high-irradiance environments with strong seasonal sun angle variation — the southwestern United States, southern Europe, the Middle East, Chile, and Australia.

Solar Tracker Cost: What Drives the Price

Solar tracker cost is typically quoted as an incremental cost above fixed-tilt mounting, measured in USD per watt ($/W) of installed capacity.

Typical incremental cost ranges:

• Single-axis tracker: $0.3–$0.5/W above fixed-tilt
• Dual-axis tracker: $0.4–$0.7/W above fixed-tilt

For a 10 MW utility project, a single-axis tracker system might add $600,000–$1,200,000 to the mounting cost. With a 20–25% energy gain, the additional revenue from power generation typically pays back this premium in 2–4 years, depending on local electricity prices.

Key cost factors:

• Steel and aluminum prices (the torque tube and piles are the largest material cost)
• Site terrain — flat sites are significantly cheaper to install
• Foundation type — driven piles vs. concrete foundations
• Control system complexity
• Local labor rates

Is a Solar Tracker Worth It for Your Project?

Solar trackers make the most sense when:

• Project size is 1 MW or larger (fixed costs amortize better at scale)
• Site is at latitude 25°–50° with good irradiance
• Land cost is high (trackers extract more energy per land area than adding more fixed panels)
• Power purchase price is high (every additional kWh generated has high value)
• Site terrain is flat or gently sloping

Fixed-tilt may be better when:

• Project is small (residential, commercial rooftop)
• Site has significant shading or uneven terrain
• Budget is constrained and simple payback period is the priority
• High-wind environment increases tracker structural requirements significantly

Super Solar's Single-Axis Tracker System

Super Solar manufactures single-axis solar tracking structures designed for utility-scale and commercial ground-mount projects. Key specifications:

• Wind resistance: Up to 55 m/s (stow mode)
• Slope adaptability: Up to 15° terrain slope
• Panel compatibility: All mainstream panel sizes up to 700W+
• Drive system: Single motor per row, low-maintenance gearbox
• Control: Astronomical algorithm + anemometer-triggered stow
• Lifespan: 25+ years, consistent with solar module life

→ View Single-Axis Tracker Specifications & Request a Quote

Frequently Asked Questions

How much do solar trackers increase energy output?

Single-axis trackers typically increase energy output by 15–25% compared to fixed-tilt systems. Dual-axis trackers can increase output by 25–35%. Actual gains depend on geographic location and local climate conditions.

Do solar trackers require a lot of maintenance?

Single-axis trackers have relatively low maintenance requirements — annual inspection of motors, gearboxes, and control systems, plus anemometer and sensor checks. The moving parts are designed for 25-year lifespans with standard lubrication schedules.

What is the difference between a tracker and a fixed-tilt system?

A fixed-tilt system holds panels at a single angle permanently optimized for average annual sun position. A tracker continuously adjusts panel angle to follow the actual sun position in real time, capturing significantly more energy.

Are solar trackers suitable for rooftop installations?

Solar trackers are not typically used on rooftops. They require ground mounting with adequate clearance for panel rotation, and the structural loads involved are not compatible with most roof structures. They are primarily used for ground-mount utility and commercial projects.

How does wind affect solar trackers?

Trackers include a stow function that automatically lays panels flat (or at a low-angle position) when wind speed exceeds a set threshold, typically 12–15 m/s. This protects panels and structure from wind damage. Stow positions are triggered by anemometers integrated with the control system.

Super Solar is a manufacturer of solar mounting structures and tracking systems based in Xiamen, China. For technical specifications, project pricing, or sample requests, contact our engineering team.