ok, so my cargo trailer roof is completely covered with panels and everything is working well so far.  except my samplex 1500 w. inverter does not like my 700 WATT microwave or induction heating plate.  but that's ok.  it's for sensitive electrical stuff like a computer (a/c type sine wave).  so i'll probably have a cheaper inverter for those items and turn it on only when using the microwave or induction hot plate.  But here is what I am thinking about now - and I appreciate anyone with similar projects:  I still have a small leftover panel that could be put on the back with a leftover charge controller with an extra battery just for stuff like charging phones, etc.  But I am thinking that if it were connected to an old-fashioned 12v relay, it could control when certain loads switch on and off from my main panels.  IE the sun is shining pretty brightly and it is enough to make the old fashioned relay switch on and - bingo - non-essential loads will be switched on from the main systems only when the sun is bright, even if I'm in bed or away.  Any experience or thoughts appreciated.