In Switzerland, solar panels are being laid down "like carpet" across railroad rails.
In May, subject to approval from the Federal Office of Transport, the Swiss startup Sun-Ways will install panels close to the Buttes train station in the country's west.
The urgency of the climate problem has led to a newfound interest in unconventional surfaces among developers as a means of accelerating Europe's energy transition.
Solar panels are being installed on reservoirs, farms, and roadside ridges. Also, the German railroad company Deutsche Bahn is experimenting with attaching solar cells to train beds.
Nonetheless, Sun-Ways is the first company to patent a removable system, thanks to EPFL, the Swiss Federal Institute of Technology in Lausanne.
The invention is that, "It's a critical one, as co-founder Baptiste Danichert told the Swissinfo news site, because railway tracks occasionally need to be cleared for necessary repair work.
How do tracks get solar panels added to them?
The replaceable solar panels are installed using a mechanical system designed by the Swiss firm, which has its headquarters in the western town of Ecublens.
Photovoltaic panels will be installed along the rails by a train created by Swiss track maintenance company Scheuchzer; it will move "like an unrolling carpet." "Sun-Ways claims this.
The one-metre-wide panels, which were pre-assembled at a Swiss factory, are unfurled by the specially constructed train using a piston mechanism.
The electricity generated by the PV system will be fed into the power grid and utilized to power residences because it would be more difficult to feed it into train operations.
How much electricity could be generated by solar panels on railroad tracks?
With regard to its eco-innovation, the startup has high goals. The 5,317 kilometer-long railway network in Switzerland may theoretically be covered with panels. An area around the size of 760 football fields would be covered by the solar cells.
Of course, extending the solar carpet into tunnels would be pointless.
According to Sun-Ways, the national rail system could generate one Terawatt-hour (TWh) of solar energy annually, which is equal to about 2% of Switzerland's total energy consumption.
After leaving the station, the business plans to expand internationally, entering Germany, Austria, and Italy.
According to Danichert, there are more than one million kilometers of railway lines in the world.
"We think our technology could be installed on 50% of the railways in the globe."
The company's trial project near Buttes, however, still has a lot to prove. The International Union of Railways is worried that the panels could develop microcracks, increase the risk of forest fires, or even cause train drivers to become distracted by reflections.
According to Sun-Ways, these panels are more durable than typical ones and may include an anti-reflection filter to keep light out of the train drivers' eyes.
Also, they have built-in sensors that guarantee appropriate operation, and brushes that are attached to the ends of trains can clean the panels' surface if necessary.
Others have argued that ice and snowfall could render the horizontal panels useless, however Sun-Ways has a solution for this issue as well. It is developing a system to dissolve precipitation that has frozen.