The study used a solar light-thermal separator device to make unilateral, bilateral, indoor, and outdoor measurements. It investigated the transmittance and heat insulation effect in different concentrations of aerogel coating and thicknesses of glass. It selected the most suitable aerogel coating concentration and aerogel glass thickness from the generation data of both optical and heat energy transfers into electric energy. Using the best conditions of three different aerogel particles, this study explored the effect of different particle sizes on optical power and thermal power.