If they lie on a flat, impact absorbing material (i.e. sand), then hail would do less damage than for standing panels. One could walk on them. If, as you propos

If they lie on a flat, impact absorbing material (i.e. sand), then hail would do less damage than for standing panels. One could walk on them. If, as you propose, put flat rigid cement below, I'd thing you could drive on them.