row will include further support elements associated with adjoining arrays and that further rows not shown of support elements may be included as well for each of the rows r1 and r2 of support elements 11 and 12 there is a member 13 that spans the elements of that row thus the elements 11 1 and 11 2 are spanned by a joist 13 1 similarly the elements 12 1 and 12 2 are spanned by a joist 13 2 when there are additional arrays with additional support elements 12 m through 12 n they can be spanned by individual joists or the joists 13 can be extended to span all or part of the elements in each row the joists 13 1 and 13 2 form two supports of a frame for solar modules 15 the mounting frame for the modules 15 is completed by rails 14 1 through 14 n while there is a separate rail for each opposed pair of support elements additional or fewer rails may be used as well in the particular embodiment of fig1 the rail spacing is governed by the width of the individual solar modules 15 once the rails 14 are in place the solar modules 15 are fastened to the rails to form a panel constituted by a plurality of modules the modules are fastened by any suitable.