How are your solar panels mounted?

My gloriously powerful and efficient factory system is mounted in its entirety to the top of one of my AC units. It does a splendid job of keeping the batterys up (as long as I'm also plugged in...) and making the little controller on the wall put on an impressive show - which I believe, was the whole point of the "solar system".
OTOH, I'm sure it adds something. It would do a good job of keeping up with a cell phone charger (for one unused phone).