Energy shields come in a couple of different forms. The earliest forms of energy shielding for space craft were nothing more than sophisticated tracking algorithms designed to track incoming debris and then vaporize it with a ship’s weapon systems. This system proved to be effective, however costly in terms of computer power, sensor usage, and energy consumption. These systems were adept at eliminating space debris and small particles but proved ineffectual at handling most incoming weapons fire and extremely small matter such as micro-meteorites that could still cause significant damage to a space vessel.
Later systems took advantage of advances in electromagnetic field manipulation to actually create a high energy barrier between the vessel and oncoming particles which would then simply impact the field and be destroyed by it. This system required nowhere nears as much computer or sensor power, although power consumption actually increased several fold. The benefits outweighed the energy cost in most instances however as these fields would handle weapons fire and all space debris including the microscopic particles that most consumer ship-board sensors were not even capable of tracking. These shields could be manually, or computer controlled to cover specific areas of the ship, i.e.: fore, aft, port, starboard, dorsal, or ventral, but not the entire vessel at once. Multiple fields could be created if multiple field generators, and power plants were installed to support such a set up.
Present systems are now tapping the gravitic super-luminal drive systems to create walls, or bubbles of graviton particles that effectively act as a solid wall or physical barrier to incoming matter/weapons fire. These systems are much more energy efficient since they are simply harnessing an existing particle rather than energizing and causing phase shifts on stored particles. These fields envelop the entire vessel and can remain engaged indefinitely in most cases, although multiple, severe, and/or sustained impacts with a graviton shield will draw increasing amounts of power from the ship’s generators and cause them to heat up at an accelerated pace, necessitating cool down periods and large/heavy heat syncs/cooling units to be installed along with the field generators.
The current generation of gravitic shielding is by far the most common and economical in use today and its refinement is leading to development of more tightly controlled, energy efficient, and smaller artificial gravity systems.