Abstract: Individual panels of solar cells are stacked one on top of the other and arranged so that incident light passes through each of the arrays of cells in each panel striking the one below it. The solar cells in each panel are selected to have a predetermined and different spectral response and thus are responsive to different frequencies of light. Electrical connection is individually made to each of the panels to collect the electrical energy generated from conversion of the light incident on the particular array of cells. Each of the panels may independently be constructed from microcrystalline thin films, amorphous silicon, single crystal silicon, compound semi-conductors, and the like. Individual panels may be constructed of the same semi-conductor material but compositionally modified to provide sensitivity to different portions of the light spectrum.