An OHTL (Overhead transmission line) conductor is a specialized cable designed to transmit electrical energy through the air, supported by towers or poles. Unlike underground cables, OHTL conductors are typically uninsulated or "bare," and their design must balance several critical factors:

1. High Electrical Conductivity: To minimize energy loss during transmission.

2. High Tensile Strength: To withstand the conductor's own weight, wind, ice, and other environmental loads over long spans.

3. Light Weight: To reduce the structural load on the supporting towers and poles, which lowers construction costs.

The material of an OHTL conductor is a strategic compromise between these factors. While copper has higher conductivity, aluminum is the preferred material due to its much lower weight and cost.