Judgment: FAKE. 99% certainty (still a striking image, nicely done).

This is probably a Photoshop composite made by combining a sunset (or sunrise) image with a nighttime lightning image.

No one knows exactly when lightning will strike, but it is not hard to photograph.
You simply point a firmly mounted camera where lightning might strike and open the
shutter for some period determined by the brightness of the sky -- up to several
seconds if it's really dark. If you get a lightning strike during the predetermined
interval, fine; if you don't, then delete that exposure and start another one.

Sunset exposures, on the other hand, are very brief. It is unlikely you'd catch a
lightning strike while taking a sunset shot; however, it's not impossible, especially
if you're using a neutral density filter, in which case your exposure might be fairly long.

Bottom line: This shot would be so difficult to capture naturally and so easy to fake
in Photoshop that we have to conclude it is indeed a fake. The clincher is the fact
that the lightning is emerging from fairly clear sky, not a thundercloud.