Photovoltaic systems: enough space in Bavaria
The Potential Area Calculator from the Reiner Lemoine Institute also shows how much space an outdoor PV system could have.
When calculating the area over which such systems can be installed, the same exclusion criteria apply for wind energy. Settlements, infrastructure or bodies of water are excluded. A distance of at least 100 meters has also been maintained around forests, as the shade of trees can limit electricity production. Unlike wind turbines, there is no minimum distance for communities with open space PV systems.
The calculator can also be used to exclude areas that were not eligible for support under EEG 2021 in order to reflect current EEG conditions.
If all of these areas are now excluded, apart from actual solar radiation, there is an area of 1,819.5 square kilometers over which solar energy can be generated in open spaces – 2.6 percent of the total area of the Free State. According to the researchers, 186 terawatts of electricity could be generated annually – more than double what Bavaria currently consumes. If the EEG limits were raised, the amount would increase to 205.6 TWh.
The study shows: 100% renewable energy is possible in Bavaria
It also deals with the potential of renewable energies Study “100% Renewable Energy for Bavaria” Chair of Energy Systems at the Technical University of Munich, the Bavarian Center for Applied Energy Research and the BUND for Nature Conservation in Bavaria.
In the base scenario, the study authors assume that half of the primary energy consumed so far could be saved – for example through more efficient appliances or better insulation. However, the demand for electricity is increasing due to electrically driven heat pumps and electric mobility. In order to cover this electricity need by 100 percent from renewable energies, the researchers came up with an installed photovoltaic capacity of 66.6 gigawatts.
This requires an open area of 133 sq km and a roof area of 266 sq km. In the case of open space units, more space is generally required so that the units themselves are not suffocated by shadows. For comparison: the Agora photovoltaic calculator assumes a usable open area of 1,819.5 square kilometers – so the area would be sufficient.
Roofs are usually not adapted to sunlight. To calculate the required roof areas, the researchers in the study “100% Renewable Energy for Bavaria” measured orientations and inclinations differently. However, the floor plan area available in Bavaria is three times greater than the required roof area. “From a technical point of view, almost any roof is suitable,” explains Tobias Schmid of the Center for Energy Economics Research. There are only the little ones Restrictions such as protection of monuments. In addition, some flat roofs of large warehouses or industrial halls are not steadily designed for photovoltaic systems and cannot bear weight with snow load.
Wind in the winter, sun in the summer
In a completely renewable energy system, solar, wind, and hydro are responsible for much of the electricity generation. We should not forget that these systems are weather dependent. Depending on solar radiation, wind speed, and amount of water, they cannot feed the same amount of energy into the grid at all times of the year and day. In order to convert the surplus of the day into the night, electricity must be stored. Photovoltaic systems are the largest generator of electricity in the summer. In winter, wind power takes over this role.
For example, four summer and winter days are visualized in the following interactive graphic. The authors of the “100 percent renewable energies for Bavaria” study used data from the German Weather Service from 2018 for the analysis. The scenario assumes about six times the PV capacity currently installed in Bavaria and twelve times the capacity of the wind turbines.