NOVELTY - The module (2) is designed to be integrated into the house roofing. In a particular implementation, it is the length of one tile, but has the width of several tiles. It comprises a double-walled hollow plastic body (3). Shells forming the walls are welded together at the edges. The body is manufactured by twin-sheet thermoforming, or by blow-molding. On top, it includes a flat mounting surface with dimensions to accommodate the photovoltaic unit (4) so that it lies flat. The surface has surrounding profiles bordering edges of the mounted photovoltaic unit.    USE - A plastic module carrying sealed photovoltaic cells, for use on pitched domestic roofs.    ADVANTAGE - This module is constructed simply and economically. It combines and works efficiently with other roof-covering modules. Plastic construction reduces weight in comparison with other known designs. Stiffness is not compromised. Cavity construction assures adequate mechanical stability. Even photovoltaic modules with large sensitive areas are accommodated. The body shape matches the photovoltaic units, their lines, supplies and the surrounding roofing. Blow-molding results in small manufacturing cycle times. All inner and outer edges and profiles are molded simultaneously. Stainless steel or aluminum mounting frames are obviated, saving costs. Use of conventional polyvinyl fluoride sheeting can be avoided. The mounting area aligns the photovoltaic unit optimally. Connections are facilitated. The cooling system improves solar cell electrical conversion efficiency, whilst at the same time providing an additional source of useful heat. IR is absorbed almost completely as potentially-useful heat, whilst UV is converted directly into electricity.    DETAILED DESCRIPTION - The mounting surface is contoured to accept the individual solar cells and/or electrical connecting lines, so that they are effectively embedded. The contouring forms a grid over the mounting surface. The edge-profiling and contouring are integral to the upper shell of the body. Underneath the mounting surface, the body includes a single or multi-part cavity arrangement for a liquid- or gaseous coolant. This has flow and return connections for a heat-absorbing fluid. The cavity is equipped with flow channels, which are molded integrally from the lower body shell. The upper shell is at least sectionally transparent. On the body, especially underneath it, one or more electrical plug connection zones are included. The photovoltaic unit has layered construction with a cover glass, solar cells and electrical circuitry. It is fixed to the body, especially using a transparent casting resin. Sealant protects the photovoltaic unit from environmental effects.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the roof which includes six modules and photovoltaic units (4).    wide, tile-like modules (2)    double-walled hollow plastic body (3)    photovoltaic unit (4)