Even that you don't need indeed, you can have everything powered if you want. I was able to get all the fuses that are hidden in the facility and power on everything. You need to get a screwdriver to be able to get to the room where one of the fuses is, through the vent in the archives. And to get the screwdriver, you need to find two runes and give them to Rune (in exchange for the first rune, he gives you the facility map, and in exchange for the second one, a screwdriver). One of the runes is hidden in the facility, but for the other one, you must get it before you get to the facility.