The call initially met with great interest. An audit showed that around 260 areas along federal and state roads are suitable for the construction of PV systems. Ultimately, however, only 150 areas remained.
The reason, according to the ministry: “Interested parties who no longer pursue approved areas cite the uneconomic nature of the areas due to their size and the time-consuming and laborious process of obtaining building rights by drawing up a development plan as the main problem for the lack of implementation.” So things are progressing more slowly than expected. A survey in selected cities revealed this:
In TÜBINGEN, Mayor Boris Palmer has long been drumming up support for photovoltaics (PV) in the open spaces between the entrances and exits to expressways, which, from a bird’s eye view, are reminiscent of ears because of their shape. A showcase project nationwide is the “Lustnauer Ohr” on the B27 federal highway. It has been the largest PV system in Tübingen for two years and provides solar power for around 260 four-person households.
More green tech for Baden-Württemberg: Solar energy on federal roads in “The Länd” is to be massively expanded. Photo: Andreas Gucklhorn Unsplash
The Stadtwerke Tübingen (swt) built two circular areas of land with 2,880 PV modules. This corresponds to a total module area of almost 5,400 square meters. swt invested 800,000 euros for this.
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By the summer of 2024, swt will also have more than 15,000 photovoltaic modules installed along the B27 federal highway, thereby realizing the new “Traufwiesen” solar park. And in the new PV park, a federal road ear is again part of the solar park area. Tübingen wants to be climate neutral by 2030.
In ULM, the local council made the fundamental decision in May 2023 to build PV systems within five connection points. Before that, the expression of interest process was carried out by the state government, said Ulrich Willmann from city planning. “There are still no PV systems in inner ears in the Ulm district. The five currently planned PV systems will have a total output of 7 megawatts. Grid connections are planned for summer 2025.”
It is planned to realize all five systems as agricultural photovoltaic systems. The agricultural land is used both for plant production through photosynthesis and for generating electrical energy through photovoltaics. In total, all five systems would have an area of 8.3 hectares with around 15,500 modules and electricity for around 2,800 households.
BIBERACH only has the B30 as an expressway. The driveway (Jordanei) doesn’t really meet the definition of an ear, said a city spokeswoman. “We did receive requests for Jordan, but had to reject them. The reason was and is that the current Donau-Iller regional plan sets a green break in this area.
After consultation with the regional association, a green cut rules out the use of photovoltaics. Potential areas for open-space photovoltaics in general are included in the land use plan. Some of these are also on the B30. “So far nothing has been implemented here in Biberach.”
In REUTLINGEN, the use of junctions on expressways for solar energy was examined by the city administration. “The inner ears along expressways in Reutlingen are mostly densely forested and, in a few cases, densely planted with several large-crowned trees. There are currently no plans to clear the forest or trees in order to build photovoltaic systems there,” said a city spokeswoman. The construction of open-air photovoltaic systems on other areas in the Reutlingen city area is currently being examined.
The only expressway through GÖPPINGEN is the B10, a federal highway. According to a spokeswoman, there are no significant areas there because the exits are very closely parallel to the B10.
“There were once considerations about PV on the noise barriers along the B10, but unfortunately these were not pursued further due to the many parties involved – the federal government and several municipalities – through which the B10 runs. Open spaces on the site of former landfills are currently being examined for suitability for PV.”
In STUTTGART there is currently a study into the use of photovoltaics on street ears, the use of which must be carried out in coordination with the federal and state governments (federal or state roads). “The first area analysis in the Stuttgart district showed theoretically possible areas totaling around 4.3 hectares on the A8, B27, B10 and B14,” said a city spokesman. The final result of the study is still pending. If suitable, the city should implement photovoltaic systems on these areas.
Own use of land by the state of Baden-Württemberg for solar power generation
The city of KARLSRUHE does not yet have such photovoltaic systems. “Initial considerations have been made, but these are at a very early stage and have therefore not yet moved into the concrete planning phase,” said a city spokesman. But the potential has been recognized. “We will stay on the topic.”
The Ministry of Transport also announced that the country’s own use of land is also an option for solar power generation. “The road tunnels in particular need a lot of electricity for lighting and ventilation, for example,” said a spokesman. The extent of the potential for the use of PV systems was examined using eleven exemplary tunnel systems on federal and state roads. “Following the positive results from the investigation of eleven tunnel systems, the potential for around 80 additional tunnel systems on federal and state roads is currently being examined. The result of the analysis will be made available to the regional councils in spring 2024 as a basis for concrete planning,” explained the spokesman.
Sources
SWR, dpa