Well blinds would presumably block the light you want in (visual spectrum). Furthermore, anything that isn't reflected back out serves to heat the building. Abs

Well blinds would presumably block the light you want in (visual spectrum). Furthermore, anything that isn't reflected back out serves to heat the building. Absorbing the energy in a PV material takes some fraction of energy that would otherwise become heat and turns it into something valuable. Efficiency is very important but just one-big factor to consider in your application. Less efficient panels can have other benefits that justify their use. Crystalline silicon panels are more efficient than thin film but thin films are lighter and so can be used on roofs that don't support the heavier panels.