Austria's largest photovoltaic system is currently located in Vienna. The 11.45 megawatt system produces over 12 gigawatt hours of solar power for 4,900 Viennese households every year. At the same time, it can also be used for agricultural purposes: the plant is designed as an agricultural photovoltaic system and is therefore a prime example of environmentally friendly and space-efficient ground-mounted systems. Every year, the giant solar power plant with its 25,626 modules saves 4,200 tonnes of CO and thus makes a decisive contribution to greater climate protection in the city. We built the plant for Wien Energie on the 12.5 hectare site of a former gravel dump in the city.
Solar power between sheep and celery
From April to October, the area under the solar power plant serves as a pasture for 150 Jura sheep. As natural lawnmowers, they ensure that the grass does not grow too tall and are also protected from the elements thanks to the photovoltaic modules.Part of the system has also been realised as an agricultural photovoltaic system. The 400 or so modules are bifacial - i.e. they produce electricity on both sides - and are positioned vertically. This means that a tractor can easily drive between the rows of modules and the area can be used for agricultural purposes, such as growing vegetables. The area between the agricultural photovoltaic modules is thus used up to 60 per cent more efficiently. This innovative form of photovoltaics has already been successfully trialled by Wien Energie and is now being used on a larger scale in Schafflerhofstrasse. In order to analyse the effects of dual use, Wien Energie is conducting accompanying research together with the University of Natural Resources and Life Sciences, which will also manage the area.
Technical masterpiece: one line for two green energy plants
With systems of this size, connecting to the power grid is also a challenge, as it could be overloaded during production peaks. The innovative solution: the Schafflerhofstraße photovoltaic system is part of a ‘hybrid power plant’. It is connected to the same power line as the Wien Energie wind farm in Andlersdorf. This supplies up to 9 megawatts of power to the grid. Wind and solar peaks are rarely at the same time, so both plants can run at full capacity at the same time without overloading the electricity grid. Should more renewable electricity be produced despite this, a buffer power storage system is used. It intercepts production peaks and only feeds the solar power produced into the grid at a later point in time.
