"Photovoltaics" refers to the direct conversion of light into electricity. The physical principle – the photoelectric effect – was discovered as early as 1839. Solar cells have been powering spacecraft since 1958 and have proven to be very reliable. Solar cells have already been used on a significant scale on earth for around 20 years. Here, it is possible to convert the direct current generated into grid-compliant alternating current in inverters and feed it into the public grid.
In more and more countries, electricity fed into the grid is remunerated in an economically enticing way or consumed by the producer themselves.
Ground-based solar parks
Areas of application: Compensatory areas from economic, housing or military use. So spoil heaps, former open-cast mining areas, military training areas and ammunition depots. Also areas along motorways or railway tracks at a distance of up to 110 metres. Agricultural land and grassland, only if they are located in a less-favoured area per Directive 86/465/EEC and have been approved for PV use by the federal states.
Components: For ground-based systems, we install the modules using a fixed mounting system. Regardless of the substrate, a steel or aluminium frame is anchored in the ground by pile driving or screwed to concrete blocks; the angle of the modules is not changed after assembly.
Benefit: Fallow and unused open spaces can be used economically and profitably. There can be a profit share via the ongoing yields of the photovoltaic system or a one-off lease payment can be made. A study by the bne [German Association of Energy Market Innovators] also shows that ground-mounted photovoltaic systems make a high contribution to regional biodiversity and that the installation of a solar park makes it possible to significantly enhance the ecological value of the land compared to arable land or intensive grassland use.
Rooftop photovoltaic systems
Areas of application: Commercial roof areas offer great potential. Not only gable roofs are suitable for the installation of a photovoltaic system. Many warehouses or production halls offer suitable conditions. We have also successfully installed photovoltaic systems on rare types of construction, such as sawtooth roofs, and sustainably increased the value of the commercial property.
Components: The high-performance solar modules of a rooftop photovoltaic system are mounted on the flat or sloping roof surface on a substructure. On gable roofs, the installation is carried out using roof hooks mounted on the rafters.
Benefit: Companies are currently benefiting from a cost degression of 80 percent in PV modules and system prices over the last decade. A commercial rooftop system currently costs 600 to 800 euros per kW to be installed, depending on the size. The solar electricity generated by the solar power plants on the roof then costs between 6 and 8 cents (plus EEG [German renewable energy sources act] contribution) per kWh.