Roof structure for a solar system

Abstract

A roof structure ( 10 ) for photovoltaic generation of electric current and/or for heating a flowing medium, in particular an airflow ( 14, 20 ), comprises glass roof panels ( 24 ) that are flat, transparent or equipped at least partially with solar cells ( 60 ) of flat design. Said panels are laid at a spacing (a) from a subroof ( 12 ) with formation of an airtight flat gap ( 18 ) that is largely free of obstructions in the flow direction, and are preferably of square or rectangular design.

1 . A roof structure ( 10 ) for photovoltaic generation of electric current and/or for heating a flowing medium, in particular an airflow ( 14 ,  20 ),
 characterized in that   glass roof panels ( 24 ) that are transparent or equipped at least partially with solar cells ( 60 ) of flat design and form an airtight flat gap ( 18 ) which is largely free of obstructions in the flow direction ( 16 ) are laid and sealed at a spacing (a) from a subroof ( 12 ).   
     
     
         2 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the solar cells ( 60 ) consist of a photosensitive semiconductor material that converts photons into electric voltage, in particular of high purity amorphous silicon. 
     
     
         3 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that at least a portion of the laid glass roof panels ( 24 ) is constructed as a laminate that comprises a hardened front glass ( 70 ) also having an antireflection layer ( 72 ), thereunder a layer of a plastic embedding compound ( 74 ) with the solar cells ( 60 ), accessible uncovered for the sunlight (S 1 ), and a rear wall sheet ( 76 ) protecting the glass roof panels ( 24 ) from below. 
     
     
         4 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the glass roof panels ( 24 ) are constructed at least partially as a 35 laminate that comprises a hardened front glass ( 70 ), also with an antireflection layer ( 72 ), thereunder a layer of a transparent plastic embedding compound ( 74 ) with the solar cells ( 60 ), and a transparent protective panel or protective sheet ( 76 ) protecting the translucent glass roof panels ( 24 ) from below. 
     
     
         5 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the glass roof panels ( 24 ) are constructed at least partially as a laminate that comprises a hardened front panel ( 70 ), also with an antireflection layer ( 72 ), thereunder thin-layer solar cells ( 60 ), deposited directly onto the glass roof panel ( 24 ) with a chemical or physical deposition method, and a rear wall sheet ( 76 ) protecting the glass roof panels ( 24 ) from below, or a corresponding transparent protective layer or sheet for translucent glass roof panels ( 24 ). 
     
     
         6 . The roof structure ( 10 ) as claimed in  claim 3 , characterized in that the glass roof panels ( 24 ) have a grid of flat solar cells ( 60 ) that are arranged abutting or have an all round spacing (b) in the case of translucent glass roof panels ( 24 ), preferably up to the largest linear dimension of the solar cell. 
     
     
         7 . The roof structure ( 10 ) as claimed in  claim 3 , characterized in that the embedding ( 74 ) of the solar cells ( 60 ) consists of plastic, preferably also of transparent ethyl vinyl acetate (EVA). 
     
     
         8 . A solar roof ( 10 ) as claimed in  claim 1 , characterized in that the flat gap ( 18 ) has at least one entrance opening for the cold airflow ( 14 ), at least one exit opening for the warm airflow ( 20 ), and an airtight outer roof edge surround. 
     
     
         9 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the spacing (a) between the subroof ( 12 ) and the glass roof panels ( 24 ) is in the range of 10-30 mm, preferably approximately 20 mm. 
     
     
         10 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the subroof ( 12 ) and the glass roof panels ( 24 ) run parallel or, particularly given glass roof panels ( 24 ) narrowering in the flow direction ( 16 ) of the air, form a widening flat gap ( 18 ) in this direction. 
     
     
         11 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the square or rectangular glass roof panels ( 24 ) are laid in overlapping sealed fashion and preferably with a diagonal approximately in the flow direction ( 16 ) of the air. 
     
     
         12 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the glass roof panels ( 24 ) are supported in the corner region or with sealing and collecting tracks ( 66 ) running in the flow direction ( 16 ) of the air. 
     
     
         13 . The roof structure ( 10 ) as claimed in  claim 12 , characterized in that the tracks ( 66 ) have through openings for the airflow ( 14 ,  20 ) and the electrical cabling, which is preferably of flat design. 
     
     
         14 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the individual glass roof panels ( 24 ) are sealed with a frame ( 68 ) and are laid and supported on a plane or in the form of a shingle roof. 
     
     
         15 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that the subroof ( 12 ) is covered with a black, preferably selective absorber layer ( 64 ) for sunlight (S 2 ), in particular in the region of transparent and translucent glass roof panels ( 24 ). 
     
     
         16 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that, in the case of sloping roofs, glass roof panels ( 24 ) covered completely or to a high degree by solar cells ( 60 ) are arranged in the lower region, while glass roof panels ( 24 ) with a low degree of cover or complete transparency are arranged in the upper region. 
     
     
         17 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that a pipeline system ( 30 ) for transporting the warm airflow ( 20 ) away is connected to the exit openings. 
     
     
         18 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that a ventilator ( 28 ) which is preferably sensor controlled in accordance with the intensity of the sunlight (S 1 , S 2 ) is arranged, particularly in the region of the exit openings for the warm air ( 20 ) from the flat gap ( 18 ), for the purpose of regulating and supporting the natural airflow ( 14 ,  20 ). 
     
     
         19 . The roof structure ( 10 ) as claimed in  claim 17 , characterized in that a heat exchanger ( 40 ), preferably an air/water one, with a water circuit ( 42 ) is installed next to the exit openings for the warm air ( 20 ). 
     
     
         20 . The roof structure ( 10 ) as claimed in  claim 1 , characterized in that a closed circuit with a ventilator ( 28 ) and a heat exchanger ( 40 ) is constructed for the airflow ( 14 ,  20 ) through the flat gap ( 18 ).