German and Austrian researchers are working on building a pilot of a PV canopy concept. The project may not only generate 10% of the country’s electricity demand but also help the environment with the slow erosion of highway tarmac.
Germany’s Autobahn, the country’s network of high-speed highways, has earned respect for speed-seeking petrolheads. However, speeding could turn into a climate problem case with increasing CO2 emissions and turning highways of the country home to the energy transition.
European researchers are now assessing whether the Autobahn networks, covering 2.6% of the overall area of the country could help the environment. The team is probing whether canopies covering the Autobahn stretches could be fitted with solar panels. The fitments may contribute to the energy transition in Germany.
With 13,000km of the Autobahn network, using PV panels with a capacity of 180watts per square metre could result in a capacity of 56GW. The output is more than the 49GW that Germany had installed at the end of 2019. According to Martin Heinrich, head of the PV module products team at Germany’s Fraunhofer Institute for Solar Energy Systems (ISE), the PV canopy would produce some 47TWh of clean energy per year. The estimated production of solar power could meet up to 9% of the country’s power needs.
Autobahn does not cover all stretches, and parts of it run through tunnels, shadowy stretches, and below bridges. These stretches would be uneconomic for solar power production. Heinrich reiterated that it would be difficult to specify a technological potential. He added that they were still analysing details.
The researchers are also working with traffic engineering company Foster Industrietechnik to see whether PV canopies would offer added value for road maintenance, by protecting the tarmac. The researchers now plan to build a demonstration roof on a 20-40 metre stretch of an Autobahn, probably in southern Germany. The roof would be at the entrance or exit of a service area, for a one-year test programme to study energy yield and to monitor stability, impact safety, maintenance options, and traffic safety.
The cost of building these solar canopies on the Autobahn is still not clear, but best estimates suggest they will be equal or higher than those of PV installations on private homes. The costs are close to €300/m2 ($355/m2) a square metre and substantially more than ground-based arrays, which estimates roughly to be €125/m2.