It's funtcion is simple; to relay power to remote areas who are out of a normal Power Plant's reach. Instead of having to build a new (and expensive) power plant, an Energy Transmitter can provide the same reach, the only difference is that it doesn't actually create power, but only transmits it. This way, entire networks of Energy Transmitters can be built to give energy to buildings on the other side of the map, where you don't have Power Plants.
The downside to this is that these Transmitters are quite weak and cannot with stand (much) enemy fire. If even a single one is destroyed, and there is no back-up, then your entire power network may collapse. This is entirely true for Earth 2150. In Earth 2160, transmitter are somewhat more resistant, but are still very vunerable.
Energy transmitter equipped with long-range General Electric GE ET2-4A energy beam transmitters and protective energy field generators.
|Power Plant (Hellfire Generator - Energy Coordination Center) - Energy Transmitter - Refinery (Refinery Landing Zone - Storage) - Engineering Facility (Technology Bay - Light Unit Factory - Heavy Unit Factory - Bomber Wharf - Unit Teleport Facility - Bomb Teleport Facility)|
Main Defense Tower (Bunker - Heavy Defense Station - High Defense Tower) - Barrage
|Silver One - Silver P - Decker|
Drone - Termite - Reloader - Scarab - Beetle - Condor
Spider - Kazuar - Jaguar - Lion - Scorpion - Salamander