A mounting system for supporting a plurality of photovoltaic modules on a support surface, such as a low-sloped roof, is disclosed herein. The mounting system includes a plurality of telescoping tubular members configured to support photovoltaic modules on a support surface, and configured to be adjustably attached to one another so as to accommodate undulations and uneven regions of the support surface, and at least one of the plurality of telescoping tubular members comprising an arched portion so as to accommodate thermal expansion and contraction. In another embodiment, a plurality of strut members are used to support the modules. In yet another embodiment, a plurality of support members adjustably support one or more photovoltaic modules on a support surface so that the one or more photovoltaic modules are capable of passively tilting in response to external forces acting thereon and/or a heat source, such as the sun, acting thereon.