Compositionally, this shot is interesting because the power lines lead the lines out of the shot. I think having a little less sky and more "ground" would have given a more stable feeling and a better balanced composition, though.
There is an orangish cast to the whole picture. While this makes for an interesting sky, it makes the dark parts not as effective. If it were possible to up the contrast without ruining the orange sky, that might make it a bit more dramatic.
Finally, I am seeing some noise, especially in the sky, that I am assuming is from either a) adjusting the brightness of the overall shot or b) a long exposure. A noise filter or plug-in may help. NeatImage, when used judiciously can be helpful.
Great sky, a bit noisy, would have been interesting running it through a heavy Neat image session to get a more paintery effect....just my opinion/taste ignore it