Half-cell modules are promising candidates for new innovative module designs as they offer major advantages. Modified connection schemes reduce the serial resistance losses yielding a higher overall module performance. The reduced size of the cells allows a more flexible module design that is needed for special applications such as implementations on curved surface. Furthermore, a better performance under partial shading can be achieved. However, these advantages lead to a benefit only if the losses induced by the cell separation process are negligible. In this work, we study the different sources of power reduction, i.e. increased shunting and recombination, for mono-crystalline and multi-crystalline silicon solar cells separated using different laser process parameters. It is shown that recombination plays the major role for an optimized laser separation process. Additionally we identify the laser scribing process as the major source of losses in comparison to the mechanical breaking.