The present invention is a combination non-imaging concentrator in which at least one surface or volume is incorporated as an optical element to increase obliquity of reflection at walls of a light guide. The combination non-imaging concentrator may be used in a solar energy system to receive solar radiation from optical components and then output the solar radiation to a photovoltaic cell for conversion to electricity. One or more lenses may be formed integrally with the light guide, or may be used in conjunction with the light guide as separate components.