A solar power system includes a plurality of solar power cells mounted on an outer surface of a spherical frame, the spherical frame including an inner surface that defines an interior volume; a heat sink that includes a hollow housing mounted within the interior volume of the spherical frame; and a phase change material positioned in the hollow housing of the heat sink, the phase change material thermally coupled to the inner surface of the spherical frame to receive heat from the outer surface of the spherical frame.