If you attach your normal power source / base to one side, and something else to the opposite that you don't need power running to all the time, you can use the switch to prevent power from going to those un-needed modules. In this example, the construction yard still uses 2.5 power even when not in use, so flipping the switch to off keeps that power and stores it in the batteries instead:
Deconstructing the conduit cable would have the same effect.