N-type silicon solar cells with boron doped emitter processed in solar grade Czochralski (Cz) wafers with the rear area covered with Ag paste from 9 % to 53 % were fabricated and sorted. Eight PV modules were assembled using the standard process of the PV industry. The fill factor of solar cells was lower than that expected due to the higher resistivity of the Ag/Al paste used to form the front metal grid. When the Ag/Sn/Cu ribbon was soldered on the front busbars of the solar cells the fill factor rose from 0.70 to 0.75, causing an increase in the efficiency from 13.2 % to 15.0 %. The fill factor of solar cells was not affected by the reduction of the metal grid area on the rear face. Solar cells with rear metal coverage of 9 % and 14 % presented higher JSC than the cells with a rear metal grid of 53 %.