Types of Solar Trackers: Single-Axis, Tilted Single-Axis and Dual-Axis Compared

BTR Enerji Engineering Team · Updated: 25 September 2026 · 4 min read

A solar tracker is a mechanical and electronic system that orients PV modules to follow the sun's daily (and, for some types, seasonal) movement, increasing the irradiance on the module surface. The right type depends on the land, project size, budget and maintenance capacity.

Types of solar trackers

1. Horizontal single-axis tracker (HSAT)

The most common type in ground-mounted solar plants. Modules rotate east to west around a horizontal north-south axis. The structure is simple, with one drive per row, and it scales well on large sites. It typically produces 15–25% more energy than a fixed-tilt system of the same capacity.

2. Tilted single-axis tracker

The rotation axis is inclined at a fixed angle, which gives slightly more winter production at high latitudes. Because wind loads and structural cost increase, it is rarely used in large plants.

3. Dual-axis tracker

Modules move both east-west and north-south and face the sun directly at all times. The yield gain over fixed-tilt is the highest (typically 30–40%), but the cost per structure, the maintenance effort and the land use increase significantly. It is mostly used in small or special applications.

* Compared with a fixed-tilt system of the same capacity; depends on the site, latitude and module type.

How is a solar tracker controlled?

Modern trackers calculate the sun's position with an astronomical algorithm (they do not depend on light sensors). The tracker control unit (TCU) drives the motor, and the network control unit (NCU) manages all rows on site and connects to SCADA. Wind, snow and flood sensors move the rows to a safe stow position when needed. The backtracking algorithm prevents row-to-row shading in the morning and evening.

Bifacial modules on trackers

On a tracker the modules sit higher above the ground and keep changing angle, so the rear side collects ground-reflected light better than on a fixed structure. Light-coloured ground (high albedo) increases this gain.

Which solar tracker should I choose?

• Ground-mounted PV (1 MW and above): A horizontal single-axis tracker almost always gives the best cost-to-yield balance.
• Sloped or uneven land: If the slope along the axis exceeds 10–15%, consider shorter rows, local grading or fixed-tilt (slope tolerance guide).
• Rooftop PV: Trackers are not suitable; fixed structures are used.
• Budget and payback: Base the decision on how quickly the extra investment pays back through extra yield (cost guide).

Frequently asked questions

How much does a solar tracker increase efficiency?

Horizontal single-axis trackers typically produce 15-25% more annual energy than a fixed-tilt system of the same capacity, and dual-axis trackers 30-40% more. The exact value depends on the site and latitude.

Single-axis or dual-axis solar tracker: which is better?

For utility-scale ground-mounted PV, single-axis trackers are usually more profitable because of their cost and maintenance balance. Dual-axis trackers produce more, but their unit cost and maintenance needs are significantly higher.

Can solar trackers be installed on a roof?

Usually not. Because of the tracker's range of motion, wind loads and row spacing requirements, rooftop PV uses fixed structures.

The ratios on this page are typical industry ranges and are not binding; exact values are determined by a site-specific analysis.