In Part III of Solar Power System Design, I like to discuss the wiring diagram of my new off-grid photo voltaic system in some detail. I disclaim once again: This, following articles and downloadable material to which I link to, shall NOT be treated as advice, instruction or a form of guideline for any sort of power system. The reason why I share my experience with you is basically because I found it difficult to find similar articles that were comprehensive enough. Furthermore, my intention is to offer useful information to anybody who is interested in setting up an off-grid solar power system, so that they can make better informed decisions and understand concepts involved. After all, a sound working knowledge of your off-grid power system is required even if you don’t do it yourself.