A solar module having at least two substring groups, each including an upper substring having solar cells connected in series and arranged in a matrix having two adjacent columns and a plurality of rows, and a lower substring having solar cells connected in series and arranged in a matrix having two adjacent columns and a plurality of rows. The lower and upper substrings include the same number of solar cells. A cross-connector interconnects the lower and upper substrings electrically in parallel forming the substring group. A bypass diode is arranged electrically in the cross-connector, and cross-connectors of each substring group are interconnected electrically in series. Two columns of the lower substring include a different number of solar cells and two columns of the upper substring include a different number of solar cells, such that the number of solar cells of the upper substring and of the lower substring is odd.