This is the very first "puzzle" to solve: nothing hard to manage.
As soon as you exit the base, follow the path in the snow between the flags and below the lights and reach a second building.
Enter and face the door just in front of you: it's stuck by some crates, however just continue pushing it and eventually it opens.
Now go inside and look at your left: open the cage and extract the generator: fill it with the fuel tank you'll found on your feed (right corner). Now you have to fix it: find the tape on the opposite side of the room (it's inside a tool box).
Now push the generator back and return to the previous room: on your right you'll find a couple of levels: push them up to turn the power on.