This paper presents the effect of the illumination type on the performance of photovoltaic energy harvesting for application in buildings. A range of different types of solar cells are available to suit differing illumination sources and intensities. Modules made from polycrystalline silicon, amorphous silicon and dye-sensitized TiO2 were investigated under illumination from incandescent, fluorescent, white light LED and RGB colour-controllable LED light sources in this paper. It is shown that it is important to select the solar cell to suit the type of light. In this paper, the maximum power points of four types of solar cell have been investigated under three different electrical light sources for various illumination levels allowing the selection of the optimum solar cell type for a given combination of electrical light source and a particular illumination level. An analysis of the effect of varying the spectral composition of the illumination is achieved by using a colour-controllable LED to provide the primary colours of white light. Generally, most power is harvested by solar cells under incandescent illumination sources followed by compact fluorescent (CFL) and then LED. The amorphous-Si solar cells tested show a similar power output under all three illumination sources, therefore a device using these should perform consistently under all lighting sources, whereas the poly-crystalline silicon solar cell tested shows a significant difference between incandescent and CFL/white light LED sources which could restrict operation to just incandescent lighting. (C) 2014 Elsevier Ltd. All rights reserved.