Photovoltaic mounting system Photovoltaic mounting system Photovoltaic mounting systems (also called solar module racking) are used to fix solar panels on surfaces like roofs, building facades, or the ground. These mounting systems generally enable retrofitting of solar panels on roofs or as part of the structure of the building (called BIPV). The solar array of a PV system can be mounted on rooftops, generally with a few inches gap and parallel to the surface of the roof. If the rooftop is horizontal, the array is mounted with each panel aligned at an angle. If the panels are planned to be mounted before the
Length of a module formal algebraic geometry. Let "M" be a (left or right) module over some ring "R". Given a chain of submodules of "M" of the form we say that "n" is the "length" of the chain. The length of "M" is defined to be the largest length of any of its chains. If no such largest length exists, we say that "M" has infinite length. A ring "R" is said to have finite length as a ring if it has finite length as left "R" module. The zero module is the only one with length 0. Modules with length 1 are