A mounting system for photovoltaic solar panels providing support for different sized panels, and/or panels having mounting holes located in different locations. A universal panel clamp includes at least one elongated hole or slot to attach to a mounting hole on a solar panel frame. A clamp is attached to an upper hole, and a second clamp is attached to a lower mounting hole. The upper clamps are attached to an upper lateral support member, and the lower clamps are attached to a lower lateral support member. This assembly may be supported by A-shaped support members having adjustable tilt arms, or posts with specially configured brackets.