Combine Power Generator

"Well, we're in luck. There's a generator in the square outside. We're trying to disable as many as we can to loosen the Combine's grip on this sector."

- Alyx Vance

Combine Power Generators are Dark Energy-powered generators used by the Combine. They are mainly found within the Citadel, but can also be found in certain locations in City 17, such as the Overwatch Nexus, the plaza visited in the Half-Life 2 chapter Anticitizen One, or near the White Forest Inn, in the Outlands.

Overview
Often run by Energy Orbs and protected by Force Fields, generators are used to power devices such as Force Field gates, Field Bridges, locks or weaponry such as the Suppression Device. There are many more generators in the Citadel than anywhere else, supplying power to systems in the immediate area.

Anyone unlucky enough to step into or to be thrown inside a generator field will be disintegrated, just as they would be if they got hit by an Energy Orb shot by an OSIPR. The Energy Orbs launched from the weapon are similar to that of the generators, but the latter are much more powerful, capable of damaging or destroying vehicles and Synths, such as the Strider confronted in the Citadel in Half-Life 2.

With the modified Gravity Gun in Half-Life 2 and Episode One, the player can throw enemies in generator fields and use Energy Orbs against them, leading to often spectacular deaths.

Standard Energy Orb-powered generator
This type has a core with Energy Orbs floating within, which create a beam of electricity that runs from the top to the bottom of the generator. The Energy Orbs are the actual objects that generate the power, as when they are removed (with the Gravity Gun, for instance), the generator will cease to function. To restart it, a new Energy Orb must be replaced (it can be achieved with the Gravity Gun or the OSIPR). Generators powering critical systems typically have about three orbs inside them, but ones that power smaller devices will have just a single one.

This kind of generator is the one featured in the Overwatch Nexus, the plaza visited in the Half-Life 2 chapter Anticitizen One, near the White Forest Inn and the Barn Advisor. Most of the time the player must shut it down to proceed, while having to protect Alyx or Barney at the same time, sustaining heavy fire from Combine troops.

Limitless Energy Orb-powered generator
This other type is found only in the Citadel and can have a limitless amount of Energy Orbs cycling through it. These generators are often found in the big elevator shafts found in the Citadel. It is however unknown if these are actual generators or if they just transport Energy Orbs (vents located around the Citadel Core seem to fill the latter purpose).

Horizontal limitless Energy Orb-powered generator also exist. They feature sockets similar to that of the Confiscation Field and pod cleaners.

Energy Orb-powered socket generator
In Episode One, another type of generator can be found, resembling a wall socket. It is seen mostly in the lower levels of the Citadel and act as "system activation node", allowing the player to start equipment such as field bridges or the Citadel Core's containment devices. This type of power generator can be activated by launching an Energy Orb into its center, causing its four arms to retract inwards to hold it in place and begin to siphon energy from it. Two of these need to be operational if field bridges are to be in function.

This type of Combine generator is similar in function and appearance to the Aperture Science High Energy Pellet socket seen in the Aperture Science Enrichment Center, although the possible connection between the two is unknown.

Liquid-powered generator
Only seen in the Citadel, this type consists in a large cylinder made of liquid matter, with a solid base and top. This liquid matter is likely the same liquid seen in Combine Barricades. It does not use Energy Orbs.

Simple generator
Another type of generator, sometimes used on itself, sometimes located near an Energy Orb-powered generator or a Combine Heavy Door. It is prominently featured in the Overwatch Nexus. Its model is also used in the pod conveyors in the Citadel, where two are seen linked together by a laser, acting as detectors for pod contents.

List of appearances

 * Half-Life 2
 * Half-Life 2: Episode One
 * Half-Life 2: Episode Two