RE:  I was thinking one might get away with running one solar panel.

One panel, 30 panels, doesn't make any difference.  If more than one panel
you hook them in parallel.  The reason I have two panels is they are of a
size that they stack and store in the place I've made for them.  Also, I at
first figured I could get by with one 50 watt panel.  When I found I needed
more I just got another of the same physical size so it would store on top
of the first one.