Abstract: The present invention relates to a solar generator for producing electrical energy from solar energy, mounted in particular on board an artificial satellite and constituted by a plurality of pivoted panels, stacked but unfoldable, each of which comprises a thick frame inside which is disposed a thin flexible support carrying solar cells, said frame comprising intermediate stiffeners connecting two opposite sides of the frame, wherein each panel comprises, between two intermediate stiffeners and between the end intermediate stiffeners and the sides of the frame there-opposite, a plurality of wide, flat auxiliary stiffeners, transverse with respect to the intermediate stiffeners and on which said flexible support is fixed at least partially.