The modules of a single-axis tracking system are mounted on a torque tube, which rotates as the sun passes through the sky. The axis can be horizontal (most common), tilted, or even vertical. The axis of rotation is horizontal, usually orientated North-South with the modules facing toward. Suntrack® TCU (Tracker Control Unit) is the most reliable single-axis solar tracker controller. This device moves the tracker motor to follow the path of the Sun and thus optimize solar energy production. Payloads are usually solar panels, parabolic troughs, Fresnel reflectors. Single-axis tracker installation is a multi-discipline engineering execution scope—combining civil, structural, mechanical, electrical, and controls work across large land areas, often under production-rate pressure and demanding weather windows.