Solar panels are being rolled out “like carpet” on railway tracks in Switzerland.
Swiss start-up Sun-Ways is installing panels near Buttes train station in the west of the country in May, pending sign-off from the Federal Office of Transport.
As the climate crisis demands that we speed up Europe’s energy transition, developers have been seeing new potential in unusual surfaces.
Roadsides, reservoirs and farms are all finding space for solar systems. And Germany’s Deutsche Bahn is also experimenting with adding solar cells to railway sleepers.
But Sun-Ways is the first to patent a removable system, with the help of EPFL, the Swiss federal technology institute in Lausanne.
“That is the innovation," co-founder Baptiste Danichert tells the Swissinfo news site. And it’s a crucial one since railway tracks need to be cleared from time to time for essential maintenance work.
How are solar panels added to tracks?
The Swiss company, based in the western town of Ecublens, has devised a mechanical system to install its removable solar panels.
A train developed by Swiss track maintenance company Scheuchzer will travel along the rails, laying photovoltaic panels as it goes. It’s just “like an unrolling carpet", says Sun-Ways.
The specially designed train uses a piston mechanism to unfurl the one-metre-wide panels, pre-assembled at a Swiss factory.
Electricity produced by the PV system will be fed into the power grid and used to power homes as feeding it into railway operations would be a more complicated process.
How much energy could solar panels on railway lines produce?
The start-up has big ambitions for its eco-innovation. In theory, panels could be rolled out across the entirety of Switzerland’s 5,317 kilometre-long railway network. The photovoltaic cells would cover an area around the size of 760 football fields.
Obviously, there’d be little point extending the solar carpet into tunnels.
Sun-Ways estimates the national rail network could produce one Terawatt-hour (TWh) of solar energy per year, equivalent to around 2 per cent of Switzerland’s total energy consumption.
Once its train has left the station, the company wants to go transnational - extending into Germany, Austria and Italy.
"There are over a million kilometres of railway lines in the world," Danichert tells SWI Swissinfo.
“We believe that 50 per cent of the world's railways could be equipped with our system.”
The company still has a lot to prove with its pilot project near Buttes, however. The International Union of Railways has expressed concern that the panels could suffer micro-cracks, lead to a higher risk of fires in green areas and even distract train drivers with reflections.
Sun-Ways says its panels are more resistant than conventional ones and could have an anti-reflection filter to keep out of train drivers’ eyes.
Built-in sensors also ensure they work properly while brushes attached to the end of trains could remove dirt from the surface of the panels.
Some have pointed out that ice and snowfall could stop the horizontal panels from being useful, but Sun-Ways has an answer for this too. It is working on a system to melt frozen precipitation.