A system comprising: a plurality of columns extending from a mounting surface along a first axis, wherein top ends of the plurality of columns are disposed above the mounting surface; a plurality of crossbeams coupled to the top ends of the plurality of columns and extending along a second axis, wherein individual crossbeams include a first end and an opposing second end; a plurality of purlins coupled to the plurality of crossbeams and extending along a third axis, wherein a first set of purlins are coupled to the first ends of the plurality of crossbeams and a second set of purlins are coupled to the second ends of the plurality of crossbeams; a first plurality of photovoltaic module support rails extending along the second axis across the plurality of purlins, wherein individual PV module support rails include a bottom surface coupled to the plurality of purlins and a top surface defining a plurality of openings configured to accept fasteners; and a plurality of rectangular PV modules secured to the top surfaces of the first plurality of PV module support rails by fasteners that extend through the rectangular PV modules and the openings configured to accept fasteners; wherein the plurality of rectangular PV modules is disposed in portrait orientation in a first grid having columns extending along the second axis and rows extending along the third axis; and wherein a first set of rectangular PV modules in a first column and second set of rectangular PV modules in an adjacent second column are secured to a top surface of a same PV module support rail (112, 116) disposed between the first column and the second column. a plurality of columns extending from a mounting surface along a first axis, wherein top ends of the plurality of columns are disposed above the mounting surface; a plurality of crossbeams coupled to the top ends of the plurality of columns and extending along a second axis, wherein individual crossbeams include a first end and an opposing second end; a plurality of purlins coupled to the plurality of crossbeams and extending along a third axis, wherein a first set of purlins are coupled to the first ends of the plurality of crossbeams and a second set of purlins are coupled to the second ends of the plurality of crossbeams; a first plurality of photovoltaic module support rails extending along the second axis across the plurality of purlins, wherein individual PV module support rails include a bottom surface coupled to the plurality of purlins and a top surface defining a plurality of openings configured to accept fasteners; and a plurality of rectangular PV modules secured to the top surfaces of the first plurality of PV module support rails by fasteners that extend through the rectangular PV modules and the openings configured to accept fasteners; wherein the plurality of rectangular PV modules is disposed in portrait orientation in a first grid having columns extending along the second axis and rows extending along the third axis; and wherein a first set of rectangular PV modules in a first column and second set of rectangular PV modules in an adjacent second column are secured to a top surface of a same PV module support rail (112, 116) disposed between the first column and the second column.