Power Conduits
Power for the ships systems comes from one of four sources (or a mixture). Power is generated from the warp core, the fusion reactors, solar arrays or can be drawn from the ships batteries. Excess power can be routed to recharging the ships batteries or vented into space via heat sinks. Typically the warp core or fusion reactors will be powering the ship and charging the batteries. When the ship is stopped, the warp core is typically used for power generation due to its higher efficiency.
Each system on the ship uses a specific amount of power depending on how it is being used. In emergencies non-essential systems can be shut down to conserve power.
Failure to provide enough power will cause the ship to move slower than desired or if the ship cannot produce enough power, to knock certain systems offline (depending on their priority).
The power conduits are routed automatically through the ship to connect the various systems together, however decisions have to be made as to which units get priority.
For instance the number one priority might be the Warp Core containment field followed by the deuterium cooling coils. A player might then decide to route power tot he shields, or to weapons or to any other system on the ship. The ship will attempt to power the highest priority items first and work it's way down the list. This may mean that some systems are starved of power if the ship is damaged or under-powered.