See: Crafting Guide
HV-Cables have an extremely high distance-related energy loss. They can have 3 different levels of insulation. Considering that a shock from a poorly insulated HV cable will most likely prove fatal, it is recommended to insulate them well unless the cable is located in a completely unreachable area. Even then, insulation should be applied to reduce the massive energy losses.
|Cable type||EU/b||Energy loss|
|HV Uninsulated||1||1 EU every block|
|HV Insulated||0.95||1 EU every 1.05 blocks|
|HV 2x Insulated||0.9||1 EU every 1.11 blocks|
|HV 3x Insulated||0.8||1 EU every 1.25 blocks|