Researchers from Austria and Germany are investigating the practicality of solar parks over motorways. The pilot project offers many possibilities, but also brings some problems.
Seibersdorf – driving a car and generating electricity ecologically at the same time – with solar roofs over the autobahn . It still sounds rather utopian. But architects from Switzerland designed a model back in 2011 that shows how the idea could be implemented. And a German-Austrian research team is currently investigating to what extent solar roofs over motorways are suitable as electricity suppliers.
According to a report by spiegel.de , an area of around 337 square kilometers could be used to generate electricity over the highways in this country. The area corresponds to the size of Bremen. So the potential is great. After all, the length of the motorway in Germany is more than 13,000 kilometers, making it the fourth longest network in the whole world, as reported by energiezukunft.eu.
Solar roofs over motorways: protection from the weather and noise
If you build a kind of solar park consisting of solar roofs on the German autobahn, 41.5 terawatt hours of solar energy could be generated per year (* FR reported). According to t3n.de, that is the amount of energy used by a third of German private households. One advantage of expanding motorways in solar parks is their already sealed surface. For solar parks on the green field, the area first has to be developed at great expense.
In addition, the scientists suspect that the roofing could protect the road surface from the weather or from precipitation and overheating, according to a press release. This means that the roads are preserved for longer and do not have to be laboriously renewed. Additional noise protection could also be created.
There is already a motorway in China that is equipped with solar cells – however, they are not installed above the road, but on the motorway itself.
The world’s first solar highway on Thursday opened to the public in eastern China’s Shandong. The 2-kilometer-long road can convert sunlight into electricity and directly transfer it to the power grid. The highway can also charge electric vehicles. pic.twitter.com/LlJaPUmQW6
— People’s Daily, China (@PDChina) December 28, 2017
Solar park over highways: project could cost 100 billion euros
In order not to completely darken the motorways , scaffolding could be used that let enough light through, i.e. that are partially transparent. The partially transparent modules should only reduce the efficiency of the solar roofs to a very small extent. The Fraunhofer Institute for Solar Energy Systems is also involved in the pilot project of the Austrian Institute of Technology.
In the first step, the researchers want to design a suitable supporting structure and a prototype. Then the prototype for the solar system is to be built and equipped with measurement technology. The scientists then want to test the concept for a year.
However, the research team also has to reckon with high costs : In a calculation for equipping German motorways with solar roofs, Der Spiegel came to a proud sum of around 100 billion euros. Because the solar roofs would protect the streets from the weather, but the wheel abrasion or road surface would not be washed away due to the lack of precipitation. This could make roads more slippery and lose their grip. In addition, it will only become clear after the test phase what sums the costs for the major project would actually amount to. * FR is part of the nationwide Ippen digital editorial network.