For the past 18 to 20 years now, we’ve been using a solar system without any course or training or whatsoever. It was all trial and error … we burnt lots of inverters already, melted cables together, burst batteries, burnt DVD players already before, because everything was being guessed at, we never knew exactly how the stuff needs to be done. After the Principles of PV Systems course, wow! Already I could see what I was doing wrong, what was missing, what was too small or too big. I will definitely advise people to go onto these courses. Justin S, Zimbabwe