The word photography means painting, drawing or writing with light. It is impossible to make a photograph without light. The quality of your nude photography lighting depends on three things, the direction, intensity and quality of the light falling on and then reflected by your subject.
Nature has given us a large, bright light source complete with some very handy diffusers (clouds) which is wonderful for lighting nude photographs. Unfortunately we have no control over when these diffusers appear and, although the sun is always shinning it reaches us with varying intensity.