Some additional information is useful about this image. The exposure was 25 seconds (on a tripod, of course) with a Nikon D200 and Nikon 70-200 mm f2.8 lens, ... The image was substantially "worked" in photoshop to present better contrast and depth in the clouds and to create the blue color with a gradient map. Digital cameras collect lots of data - but cannot match the human eye for dynamic range response. So yes, this image is substantially altered from the data that was "captured" by the camera. Hope you enjoy this representation.
Lightning, as it turns out, looks dramatic and energetic. A typical strike (Wiki) may involve 500 MJ of energy transfer in a relatively short time. http://en.wikipedia.org/wiki/Lightning
As impressive as this sounds, the total storm energy completely dwarfs this value. These summer storm cells can easily pack energy that dwarfs nuclear bomb outputs. Solar energy stores tremendous amounts of energy in the form of water vapor. This is released to fuel a storm when an air mass becomes "unstable." This is part of the amazing water cycle that fuels climate on our little planet.