Gold cables are a Tier 2 Cable type. They suffer higher distance-related energy losses than copper cables, but are able to carry Medium Voltage, up to 128 EU/t. Gold cables have 2 different levels of insulation, with the double insulation providing smaller energy losses per tile and less shock damage from high voltage.
Uninsulated gold cables lose 1 EU every 2 blocks (0.5 EU/b). Insulated gold cables lose 1 EU every 2.22 blocks (0.45 EU/b). Double insulated gold cables lose 1 EU every 2.5 blocks (0.4 EU/B).