NOVELTY - The panel (10) has a reflective sheet provided with a concave outer surface and a convex inner surface. Another sheet is spaced apart from the former sheet, and includes another convex outer surface and another concave inner surface. A stiffening core element is placed between the sheets, and defines a set of cells (15), where the element is a rigid or semi-rigid structural member with a set of walls (42) defining a geometric shape. Rigid foam reinforcing material i.e. rigid urethane foam, is placed in the cells. A third sheet is adhered to the former concave outer surface of the former sheet.    USE - Composite structural solar panel for constructing an interconnected panel system and walls, floors, ceilings and partitions of a residential building, a commercial building and an industrial building. Uses include but are not limited to a curvilinear interconnected panel system, arcuate interconnected panel system, convex interconnected panel system and a concave interconnected panel system.    ADVANTAGE - The panel has increased load strength, increased resistance to wind loads and increased life-cycle performance. The panel uses thinner third materials including thinner reflective materials, thus improving optics, reflectivity and shatter resistance of the panel, thus providing safer handling and transport of reflective surfaces.    DETAILED DESCRIPTION - The former and latter sheets are made of metal. The core element is made of material selected from a group consisting of paper, resin or polymer impregnated paper, metal, plastic, fiberglass, graphite and fiber-filled composites. The geometric shape is selected from a group consisting of triangular, trapezoidal, rhombus, rectangular, square, diamond, pentagon, hexagon, heptagon, octagon, nonagon, decagon and circular. An INDEPENDENT CLAIM is also included for a method for producing a non-planar composite structural panel.    DESCRIPTION OF DRAWING(S) - The drawing shows a front view of a composite panel.    Composite structural solar panel (10)    Core (14)    Cells (15)    Insulating material (16)    Cell walls (42)