Several studies have already determined the power potential of different types of photovoltaic solar cells for indoor applications. However, a detailed study whether or not the use of tandem solar cell (i.e. using two solar cells with different bandgaps in a row) is beneficial for indoor use is lacking. This paper attempts to fill this lacuna by comparing the power output of different tandem solar cells with single-junctions as reference. The comparisons are done by efficiency simulations of the solar cells and the light spectra of typical artificial light sources, i.e. a typical fluorescent tube, a high pressure sodium and metal halide lamp, a typical LED lamp and a common incandescent lamp, which are compared to the outdoor AM 1.5 spectrum as reference. More specifically, we study the influence of the energy levels of the bandgaps, not only for the usual monolithic configuration, but also for a stacked set-up. By determining the relative efficiency gain compared to single-junctions, we prove the limited usefulness of tandem solar cells for indoor applications.