Modern Starships utilize Hardpoints as an assigned place to attach and power weapons. Planets are similar to starships in this way, as they are commonly the settings for great and terrible battles. In order to power, maintain and wield planetary weapons there must be a constant supply from a local Power Generator. The Hardpoints themselves are above ground, but the power lines running between them and the generator lay under the planet surface.
Upon constructing a base level Weapon Hardpoint, the power supplied can maintain low level weapons. With increased power and capability these Hardpoints are able to host a vast array of more powerful weapons.