Mounting Rail Spacers for Improved Solar Panel Durability

Solar panels generally contact the mounting structure only along the surfaces of the aluminum frame surrounding the perimeter of the panel. With no support in the middle of the panel, front side mechanical loads from snow, wind, and human factors can cause significant deflection of the panel, resulting in tensile stress in the solar cells and cell cracking that can degrade system performance. This work examines an alternative approach whereby the mounting scheme is modified to place spacer elements between the rails of the support structure and the rear side of the panel. These spacers significantly reduce the panel deflection under load, and we have demonstrated a dramatic reduction in cell cracking at high load levels and in crack opening after cyclic loading. Such spacers can be applied to either the rear of the module or to the rails on the mounting structure and could be introduced for both new installations or as protective retrofits to existing systems. The spacers can also be of sufficient thickness to cause positive deflection of the panels to introduce some protective/restorative compressive stress into the cells.