Deploying a concentrator for a photovoltaic (PV) system has been proved to be one of the most efficient ways to reduce the junction material cost per watt output, and to increase the power output per unit module area facing the sun. In this paper a novel side-mounted concentrator solar module structure and design that could be rather compact and thin compared to current designs, and yet provides good concentration efficiency is proposed and studied. The efficiency of the designed concentrators is investigated by a method of ray-tracing simulations. The design result on a 40mm x 40mm x 2mm panel concentrator reveals that a total Effective Geometrical Concentration (Cg) of 2.7 is achievable over a large acceptance angle range of 20°, which could enable non-tracking or limited 1-D tracking deployment of such concentrators. Besides, the concentrator solar cell of this design is fully planar and easily expanded into a large cell mosaic-piling like panel. As the cell in it does not need to face the sun directly, the active cell part can be shielded from the damage of high energy radiation, which makes it extremely suitable for space applications.