@tsunku, are you searching the top floor of the power plant with a helper? I normally take Leslie with me to the power plant, and I almost always find a fuse on the first day, I've also found fuses in a few other spots but mainly top floor of the power plant. You don't always find extra items with a companion, but usually you do.
You don't get the power plant running, you go through it, I usually kill the Z's because they don't respawn in buildings with 1 caveat, which I'll detail in a moment. But anyway, at each computer read the documents then answer the password correctly to increase security to 3, then you can go enter the room with the power switches and you should auto turn on the gate and your home base's power.
The caveat is this: Once you upgrade security to 3, even if you've killed all the Z's in the lower area, you get 2 more spawns of Z's so be careful going back through a "cleared" area after that that last security upgrade. Also once you turn the power back on a Z will spawn right outside the door, just wait until he's facing to away from the door, and you should be able to exit and then kill him.
Also once you clear the bottom of the power station that unlocks super-charged Z's on the map, so watch out for those Z's with that high-voltage glow.