Capacitor
The capacitor of a ship is a power storage circuit that is used in order to activate fitted modules. Note that capacitor is distinct from a ship's powergrid. Also note that running out of capacitor does not render your ship immobile.
Overview
A ship's reactor provides basic power to essential ship systems, but many modules require a burst of power in excess of the reactor's ability in order to function. Capacitor circuits are therefore installed to meet this need. As a ship's capacitor is used, unused power produced by the reactor is directed back into the capacitor, recharging it.
In other games, capacitor could be called as mana.
Capacity
The size of the capacitors vary among ships, usually bigger ships having more capacity than smaller ones. Capacitor capacity can be increased directly by training the Energy Management skill. A huge variety of skills, and in particular those in the Engineering tree, reduce the capacitor used by activating modules.
There are modules and a combat booster that further increase the ship's capacitor capacity. A few modules are listed below:
Recharge time
The time to fully recharge ships' capacitors also varies, usually those having small capacitors recharge faster. Capacitor recharge time can be reduced directly by training the Energy Systems Operation skill.
There are modules that reduce the recharge time, a few are listed below:
Role in combat
Once the capacitor is drained, a ship may be unable to fire its weapons (if they use capacitor, projectile weapons and missiles are unaffected), warp out from combat, use its repair modules or indeed any of its modules, being restricted to launching drones and moving around. Thus running out of capacitor middle of an combat can be fatal. There are modules that removes capacity, transfer your capacity to an ally or transfer opponents capacity to yourself, so capacitor management is a notable aspect in warfare.
Below are listed some items that transfer capacity from ship to ship or simply reduce the enemy's capacity.