Abstract: In this work, a hemispherical lens was used as asolar concentrator to concentrate solar light components (direct normal and diffused direct normal radiation) on thesolar cell to increase the electrical output power from thesolarcell.Optical properties of thehemispherical lens, electrical parameters of thepolycrystallineSi-Solar cell, solar radiation components (direct normal and diffused direct normal radiation) with and without alens, and output power from used asolar cell with and without lens were measured. Some conclusions are obtained; the hemispherical lens was used practically to concentrate sunlight components on solar cell where the concentration was found to be about 2x solar light components, the used hemispherical lens was found to increase the electrical output power from the solar cell about 25 % for direct normal plus diffused solar light intensitywhich relates to the action of used hemispherical lens and properties of the used solar cell.