In order for the station to run smoothly (or at all), everything runs on power. Batteries need to be recharged, and larger machines need building power to run properly. To supply this, the station needs a functional power grid. In order not to get too horribly bogged down in complex simulations, the power grid is simplified in function. Here's how it works:
Once you've got a steady source of electrical energy, the next thing you need is to store it. This is where power management options come into play.
Surge Protector: Worth noting is that you can install surge protectors as overload failsafe devices anywhere where the damage of overpowered grids is of greater risk than the results of losing power to a section. Essentially, you choose an overload level (or accept the default), and if the power in the grid spikes over that level, the Surge Protector triggers, breaks the connection, and thus preserves anything beyond that point from electrical catastrophe. By design these are triggers that must be manually reset once tripped.
Fuse: An even simpler form of surge protector, the humble fuse is set to only handle a specific amount of power and no more; exceed it and the fuse blows, breaking the connection until the fuse is replaced. Typically replaced by surge protectors, but older stations still may use these in places. Most stations have a manual override that bypasses the fuse, in case there are no spares or in situations where power must be maintained regardless of the consequences (while under attack, for instance).
Power Substations: These massive power stations are designed to store power from the main grid, and regulate its distribution to specific areas of the station. Each station comes with a breaker box that can be triggered to bypass the substation (thus wiring subcomponents directly into the grid) or can be used to force the main grid to run through the substations, filtering power. There are seven - Civilian West, Civilian East, Engineering, Command, Medical, Research, and Security - each handling power management for its particular segment of the station.
As a rule, power systems are color coded - yellow denotes wiring from power generation systems to the power source's SMES unit; red denotes wiring from power SMES units to the substations; green denotes subgrids that connect substations to APCs; and cyan denotes areas that have a self-contained SMES to act as an intermediary between substations and APCs.
SMES: Superconducting Magnetic Energy Storage, an efficient way of storing and managing large amounts of power. SMESes are built with superconducting magnetic coils, and can be upgraded to optimize energy storage or charge/discharge rate or both by adding more coils. There are many about the station, and more can be built when needed. Superconducting Magnetic Coils increase both storage and transfer rates by a moderate amount; Superconducting Transference Coils increase max transfer rates by a high amount and storage by a low amount; Superconducting Capacitance Coils increase max storage by a high amount and transfer by a low amount. You need at least one SMES Circuit Board, Superconducting Coil, two full coils of wire, five metal sheets, and ideally a segment of wire to connect the SMES to the power grid.
Cell Rack PSU: A power storage unit that is basically a rack of six batteries wired together. Less efficient than an SMES, but easier to make; also useful as a backup battery option.
Auxiliary Power Cell: Any machine that can be built with this option allows you to put in a small power cell (if it already has a large one) or a large power cell (for large machines and others that normally run off building power) to act as a backup power supply in emergencies. If applicable, the device will drain its internal battery first and trickle-charge it back up over time, but will draw from the grid if its battery is emptied.
APC: Area Power Controller, used to distribute charge from an internal cell to a room. Recharges the internal cell by drawing from the main power grid when available. Cells can be replaced or upgraded, or removed outright. When available, APCs will draw power from the grid and trickle-charge themselves.
Trickle Charge: Items with batteries that also operate on building power (as well as APCs) tend to draw 1% of the battery's capacity per second from building power if possible in order to recharge the internal battery. Note that power-hungry machines may be using battery power faster than it can be restored, so this may only be relevant when the machine is no longer in use.
Torrent Charge: This option, when enabled, allows machines to set their charge rate on the fly based on available APC power, thus allowing them to get maximum benefit from a well-powered system. Note that this can cause temporary brownouts if multiple machines on the grid are all competing for a small excess of power.
Steady Charge: This option, when enabled, draws a fixed amount of power from the grid to charge the battery, regardless of whether the device is in use or not. This allows for predictability in charging, though the device may fail when the battery runs out if the steady charge is not sufficient to meet the demand. However, in most cases devices with a Steady Charge option charge at slightly higher than the expected rate of power consumption when in use.