Solar energy has the highest potential among novel and renewable energies. In order for solar energy to be used it should first be collected. In this study, a black glass was formed by doping silicate glass with Co3O4 at a high concentration to be used as absorbent, and in addition, this black glass was also doped with CuO and Fe2O3. Optical absorptions, electrical conductivities, thermal diffusion coefficients, SEM images and EDX spectra of all glasses were obtained and effects of transition metal oxides on glass were examined. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.