OPGW, or Optical Ground Wire, is a highly innovative cable that serves a critical dual function within a transmission line. It is installed at the very top of high-voltage transmission towers, replacing the traditional overhead ground wire.

Its primary role is twofold:

1. Safety and Shielding: The metallic outer layers of the OPGW cable act as a crucial ground wire, shielding the power conductors from lightning strikes and safely conducting fault currents to the ground.

2. Communication Backbone: The optical fibers protected within the cable's core create a high-speed, reliable communication network that is essential for modern grid management.