Power Wire is a one way wire that can handle a maximum of 10,000 RF (Redstone Flux). They will only accept power if they do not contain any power in them so they will never constantly drain power. Blue side is Input and the Red side is Output. You can rotate the Power Wires output by right clicking on it (While not holding a Power Wire). You can rotate the Input side by Right Clicking while holding a Hammer. When placing a Power Wire it will orientate based on the side of the block you are looking at.

Obsidian wires can resist explosions.