Abstract: A photovoltaic system having a plurality of photovoltaic modules producing electric energy and method for operating such photovoltaic system are disclosed. With the method, the photovoltaic modules are connected to a first DC motor having a motor shaft, and a generator shaft of a three-phase generator is coupled to the motor shaft. The three-phase generator can be connected to a power grid. The motor shaft of a second DC motor can be connected to the generator shaft, with only one of the two DC motors being initially driven with the electric energy produced by the photovoltaic modules. The electric energy is subsequently divided among both the first and the second DC motor. This process significantly shortens the startup process of the photovoltaic system compared to conventional systems.

Abstract: A base frame for a parking lot roof equipped with photovoltaic modules is proposed, wherein two mirror-symmetrically constructed halves are provided, with each half having an inner arc constructed of three inner struts and an outer arc constructed of three outer struts, which are connected with each other by cross struts. The structure is light-weight and can be easily manufactured.

Abstract: A method for operating a photovoltaic system with a plurality of photovoltaic modules and with a DC motor connected to the photovoltaic modules is proposed. The motor shaft of the DC motor is coupled to a generator shaft of a three-phase generator, wherein the three-phase generator can be connected to a power grid. The motor shaft of a second DC motor can also be connected with the generator shaft, and the electric energy produced by the photovoltaic modules is initially only used for driving a single DC motor and is during the subsequent operation divided between those DC motors. A battery is provided which can be connected with the second DC motor instead of the PV system by changing the excitation of the second DC motor such that it's motor voltage corresponds to the open-circuit voltage of the battery.

Abstract: The photovoltaic system includes a plurality of photovoltaic modules which are connected to form a string or several strings connected in parallel, thereby forming a photovoltaic generator having a positive terminal and negative terminal. A DC constant voltage source connected to the photovoltaic generator to raise the potential of the positive terminal relative to ground potential. This reduces the flow of electrons out of the TCO layer of the modules, thereby reducing or completely eliminating cathode discharges which damage the modules.

Abstract: An apparatus and a method for preparing connection of a photovoltaic system (Q1) as a first energy source to a power grid (13) by way of a motor generator set (5, 6, 7) is presented. The DC motor (5) is coupled to a three-phase generator (7) by way of a shaft (6), wherein the three-phase generator (7) can be connected to the power grid (13). It has been observed that connecting this type of apparatus to the small or varying power output of the photovoltaic system (Q1) can be difficult and time-consuming. To enable a clean and quick connection, the DC motor (5) is powered with electric DC current from a second DC current source (Q2), wherein the operation of the three-phase generator (7) is matched to the conditions in the power grid (13) with the help of the second DC current source (Q2), and wherein the photovoltaic system (Q1) is connected to the DC motor (5) and the second DC current source (Q2) is disconnected from the DC motor (5) only after a complete match has been attained.

Abstract: A method and an apparatus for carrying out the method are proposed for identifying defective photovoltaic modules. Two clamp-on ammeters are provided which are connected to a test data acquisition unit for simultaneous measurement of two DC currents. The position of the clamp-on ammeters at the time of the measurement is determined with a position registration means, and measured data and position data are transmitted via an antenna to a data processing center or recorded in a data memory element for further processing.

Abstract: A lightweight support includes a corrugated base body having an elongated rectangular configuration defining an upper longitudinal rim and a lower longitudinal rim. The base body is composed of a first layer made of metal, a second layer which is made of rigid foam and applied onto the first layer, and a third layer which is made of metal and applied onto the second layer. Stabilization rails are attached to the base body in order to maintain integrity of the lightweight support when subject to stress. The stabilization rails can hereby be placed on or at or integrated in the upper and lower longitudinal rims, respectively.

Abstract: A base frame for a parking lot roof equipped with photovoltaic modules is proposed, wherein two mirror-symmetrically constructed halves are provided, with each half having an inner arc constructed of three inner struts and an outer arc constructed of three outer struts, which are connected with each other by cross struts. The structure is light-weight and can be easily manufactured.

Abstract: A mounting support for mounting at least one photovoltaic module having a glass pane on a top side of an, in particular, uneven roof panel includes an elongated strip which can be rolled up and/or unrolled in a roll-up/unroll direction. At least two attachment means for the photovoltaic module are disposed on the strip with a modular dimension. The bottom side of the support is provided in the region of the attachment means with a protruding padding to compensate for uneven roof areas. The top side of the attachment means is provided with a supporting location or surface for edges of the photovoltaic module. The mounting support can be packaged as a roll and attached in a simple and effective manner on uneven and rough roof shingles.

Abstract: A photovoltaic system includes an inverter, a photovoltaic generator with a plurality of serially connected photovoltaic modules, said photovoltaic generator connected to the inverter by an electrical supply line, a controllable fuse interconnected in the electrical supply line between the inverter and the photovoltaic generator and having a signal input, and a voltage-dependent resistor connected between the signal input of the controllable fuse and the electrical supply line and generating a control signal which triggers the controllable fuse responsive to the control signal and interrupts the electrical supply line. The controllable fuse can be used to disconnect the electrical connection of the photovoltaic system to the inverter when a switch short-circuiting one or more modules of the photovoltaic generator malfunctions. The arrangement permits operation of photovoltaic system at an operating voltage of close to 1000 V, thereby allowing use of thinner cables.

Abstract: A clamp for attaching rectangular photovoltaic modules on a module rail is constructed so that the upper edge of a first module can be installed at a greater height than the lower edge of a second module. The upper edge of the first module rests on a first supporting surface and the lower edge of the second module rests on a second supporting surface, with the both supporting surfaces disposed on a base and having the same slope. The edges of the modules are affixed on the supporting surfaces by way of a bracket (5). The design of the clamp prevents formation of hollow spaces through which melt water can enter, but from which it cannot drain.

Abstract: A method and an apparatus for setting up synchronization, with a power grid, of an inverter having a photovoltaic generator as a primary energy source is disclosed. The inverter is supplied with the energy from an additional energy source connected in parallel with input terminals of the inverter, wherein the additional energy source is a DC energy source operated independent from the primary energy source. The frequency, phase relationship and output voltage of the inverter supplied from the additional DC energy source are matched to the frequency, phase relationship and output voltage of the power grid, whereafter the primary energy source is connected to the inverter. With this method, an inverter dimensioned for a permissible open-circuit voltage can also be used under operating conditions, without requiring modifications of the circuitry of the primary energy source.

Abstract: A ground vehicle for feeding photovoltaic modules to an automatic assembly machine is disclosed, wherein the automatic assembly machine is movable on previously installed PV modules and the PV modules that still need to be installed are fed to the automatic assembly machine above a supporting structure. The ground vehicle has six vertically movable rams arranged in spaced-apart relationship in pairs in the direction of travel, with the PV modules to be installed located above the rams. Timing of the vertical ram motion is controlled so that a retracted ram of a ram pair is always extended before the other ram of the ram pair is lowered.

Abstract: A supporting structure for an open-space photovoltaic system with several ground supports arranged in at least two mutually parallel rows oriented in essentially North-South direction and installed vertically in the ground, with beams supported on free ends of the ground supports located at the same location along a row, and with module rails attached to the beams for attachment of fastening means for photovoltaic modules. The module rails are secured on or between two corresponding adjacent beams in essentially North-South direction. The free ends of the ground supports are positioned at the same height above terrain ground, so that the beams and the module rails extend essentially plane-parallel to the terrain ground. This arrangement reduces material consumption, and only a small surface area of the supporting structure is effectively exposed to wind gusts. Each row of ground supports includes ground supports with both rigid and flexible flexural characteristics.

Abstract: In a method for forecasting shadowing of a photovoltaic (PV) system due to cloud formation or movement, part of the firmament is imaged with fisheye optics onto the input optics of a digital camera. Pixel groups associated with luminous intensity ranges are formed. The spatial arrangement of the groups is analyzed to forecast shadowing of a photovoltaic system. A line extending from the PV system to the sun is formed and is continuously tracked. A reference line located inside a region around the line is formed. Passage of clouds across a reference line is analyzed. The result of the analysis is used to increase the electric power from the PV system to a minimum value through supply of additional backup energy or to reduce the electric power consumption by disconnecting users to ensure that key users do not experience a drop in supplied power below a minimum value.

Abstract: A method for operating a photovoltaic system with a plurality of photovoltaic modules and with a DC motor connected to the photovoltaic modules is proposed. The motor shaft of the DC motor is coupled to a generator shaft of a three-phase generator, wherein the three-phase generator can be connected to a power grid. The motor shaft of a second DC motor can also be connected with the generator shaft, and the electric energy produced by the photovoltaic modules is initially only used for driving a single DC motor and is during the subsequent operation divided between those DC motors. A battery is provided which can be connected with the second DC motor instead of the PV system by changing the excitation of the second DC motor such that it's motor voltage corresponds to the open-circuit voltage of the battery.

Abstract: A photovoltaic system having a plurality of photovoltaic modules producing electric energy and method for operating such photovoltaic system are disclosed. With the method, the photovoltaic modules are connected to a first DC motor having a motor shaft, and a generator shaft of a three-phase generator is coupled to the motor shaft. The three-phase generator can be connected to a power grid. The motor shaft of a second DC motor can be connected to the generator shaft, with only one of the two DC motors being initially driven with the electric energy produced by the photovoltaic modules. The electric energy is subsequently divided among both the first and the second DC motor. This process significantly shortens the startup process of the photovoltaic system compared to conventional systems.

Abstract: A method and an apparatus for removing fine-grain silicon material from coarse-grain ground silicon material are disclosed. In the method, ground silicon material is selected that exhibits a predominantly brown color in an aqueous suspension, indicating that a considerable fraction of the ground silicon material has a grain size of less than 0.25 ?m, and the ground silicon material is supplied to a reaction vessel. An aqueous or water-containing solution of a base is added to the ground silicon material, causing an etching process which chemically removes a fine fraction with a grain size of less than approximately 1 ?m. Acid or water is then added to terminate etching and cause rapid sedimentation of a suspension in form of a relatively coarse-grain solid, which can be removed for further processing. The solution formed above the relatively coarse-grain solid can also be withdrawn.

Abstract: An apparatus and a method for preparing connection of a photovoltaic system (Q1) as a first energy source to a power grid (13) by way of a motor generator set (5, 6, 7) is presented. The DC motor (5) is coupled to a three-phase generator (7) by way of a shaft (6), wherein the three-phase generator (7) can be connected to the power grid (13). It has been observed that connecting this type of apparatus to the small or varying power output of the photovoltaic system (Q1) can be difficult and time-consuming. To enable a clean and quick connection, the DC motor (5) is powered with electric DC current from a second DC current source (Q2), wherein the operation of the three-phase generator (7) is matched to the conditions in the power grid (13) with the help of the second DC current source (Q2), and wherein the photovoltaic system (Q1) is connected to the DC motor (5) and the second DC current source (Q2) is disconnected from the DC motor (5) only after a complete match has been attained.

Abstract: A photovoltaic system includes a plurality of photovoltaic modules and a DC motor connected to a three-phase generator driven by a shaft. The three-phase generator is connected to a power mains. The electric power supplied to the DC motor by the plurality of photovoltaic modules is repeatedly measured and adjusted, by changing an external excitation current of the DC motor, to the peak power attainable at the current ambient temperature and the current incident solar radiation intensity. The peak power is preferably determined by incrementally changing the excitation current in predetermined time intervals, until the supplied electric power produces a power level which can be regarded as the peak power.