The diffraction and the dispersion properties of holographic optical elements are examined for use as solar concentrators for photovoltaic and hybrid photovoltaic/thermal energy conversion systems. The diffraction angle and efficiency are computed for folded optical geometries that are potentially useful for low concentration ratio systems that can reduce the cost of residential solar energy systems. An investigation of the collection efficiency of a holographic planar concentrator and a spectrum splitting concentrator are analyzed with different construction parameters. It is found that collection angles of 40o and spectral bandwidth of 70 nm result with folded optical geometries for single volume holograms.