The right term for power grid is an "electrical grid".
A grid is an inter-connected network meant to deliver electric-power from suppliers to consumers.
You can relate electrical grid to a river of water, where grid plays the role of the river, and electricity plays the role of water. You can take (consume) as much of water from a river. Also, you can add as much of water as you want to a river.
Don't question me what a draught is :P