depends....If your panel is bigger than a shoe box then, yes, its too big
A small panel is useless. If you get a panel big enough to be useful then you will have problems like weight and surface area. The antenna mast can only lift so much. The surface area is a problem too, when the wind blows you'll have a sail. The mast should have been designed for the wind load based on the surface area of the antenna...any more might be a problem.