Let me just start by saying that I'm a sucker for power station photos for some reason. I also work at a power station.
As far as your photos go, #3 is the best by far composition wise, however it has major noise issues and the white balance is a bit off. It could also use a general crop to get rid of some dead space around all sides.
#1 is the cleanest looking image, and I like the foreground in it, however I wish it was panned to the right a bit so that the building with lights wasn't cut off, and the cooling tower (main subject) is to the left of the frame.
#2 has a severe blue colour cast, and I'm not a fan of the composition. Again, should be panned to the right to include more of the building and have the tower off to the left.
I'd love to see you try these again if possible and repost in here.
I had crazy settings from experimenting with my camera from the night before and forgot to change them back, thus the noise on the last picture. I was kicking myself as this one was probably the best IMO, despite the noise. Also, I was a goober and couldn't figure out why my auto focus wasn't working.......maybe because it was set to manual focus. :x
Since I go by here every day to work, I plan on trying again and this time paying more attention to the settings on my camera.
What kind of power station do you work at? Nuke, coal, etc....