Mounting structures are used to fix PV modules to the roof or to the ground so that they aren't moved by wind or snow.

Some ground-mounting systems fasten to the bottom flange using specialized clips, enabling installers to perform virtually all of their work underneath the modules. Top clamps, which clamp the module frame to a mounting rail or roof attachment, are most popular today as the clamps can double as spacers and clamp two modules simultaneously, reducing the total     number of fasteners required.

Most PV modules are designed to be clamped at the quarter-points where the mounting holes typically are. This ensures     optimal loading on the module frame and provides maximum static and dynamic load capacity.