Switzerland has completed a full year of running trains directly on the world’s first solar power plant built into an active railway line, and the results have been promising enough that Italy could be the next country to try the same idea. The project, developed by Swiss startup Sun-Ways, consists of 48 specially designed solar panels installed between the sleepers of a hundred meters of track in the village of Butes in the canton of Neuchâtel. Trains have been running on exactly the same panels as before, with no disruption to services and no incidents of glare distracting drivers, even though the setup was originally approved only as a three-year trial. With those early results, Sun-Ways has now signed a cooperation agreement with an Italian partner in contact with the country’s national rail operator, and several other countries are also watching closely.
How did the solar panels disappear between the railway tracks?
The idea behind Sun-Ways is quite simple, railway corridors represent large amounts of open, sun-exposed land that already exists and are rarely used for anything beyond the tracks, making them an obvious candidate for solar power without the need to buy or clear any new land. The panels sit directly on sleepers between the rails and were designed to be removable, as maintenance crews regularly need to access the tracks beneath for repair, grinding, and general maintenance. A purpose-built machine developed by Swiss maintenance company Scheuchzer can install or remove nearly a thousand square meters of panels in a single day, addressing one of the biggest practical objections that has previously stopped similar solar concepts on rail elsewhere in the world.
Addressing safety concerns of railway regulators
Before the pilot project could begin, Sun-Ways had to respond to some safety concerns raised by rail regulators and industry bodies. The International Union of Railways had expressed concern that the constant vibration of passing trains could cause micro cracks to develop in the panels, increasing the risk of fire, or reflect sunlight in a way that could distract drivers. Sun-Ways responded by manufacturing stronger panels than standard rooftop versions and fitting them with anti-reflection filters, as well as built-in sensors to monitor their condition and brushes attached to passing trains that automatically clean dirt from panel surfaces. According to an update reported by Swiss public broadcaster SWI swissinfo.ch, Swiss authorities had actually rejected the project once before in 2023 due to these same maintenance and safety concerns, eventually approving a three-year pilot after Sun-Ways commissioned an independent engineering study to demonstrate that the panels would not interfere with active rail operations.
Why do the results look encouraging after one year?
After a year-long test, Sun-Ways reports that the installation worked without any problems and did not require any special maintenance beyond the original plan. The electricity generated by the panels is currently fed directly into the local power grid rather than feeding into the railway’s own traction system, although the company says it is already working on a version that could eventually power trains directly, describing it as an almost self-driving railway. If the panels were installed across Switzerland’s approximately 5,300-kilometre-long railway network, excluding tunnels and less-sunny stretches, Sun-Ways estimates the system could generate about one terawatt hour of electricity annually, enough to power about 300,000 homes and cover about two percent of the country’s total electricity consumption.
The Physics Behind Why Tilt Angle Really Matters
One technical limitation of laying solar panels flat between railway tracks is that they cannot be tilted towards the sun like rooftop panels, which naturally reduces how efficiently they capture sunlight over the course of a year. According to a study published in the journal Sustainable Energy Technologies and Assessment, researchers analyzing photovoltaic systems in the Iberian Peninsula found that a fixed tilt angle of about 34 degrees kept the annual production loss less than one percent compared to perfectly angled panels for each specific location throughout the year, as the ideal tilt angle does not vary dramatically enough across most of the same region to meaningfully impact overall production. Sun-Ways separately estimates that the complete lack of any tilt on its railway mounted panels costs about ten percent of the potential output compared to an optimally inclined roof system, a manageable compromise given how much unused space the design opens up in return.
Why are Italy and other countries taking notice?
Following positive results in Switzerland, Sun-Ways has signed a cooperation contract with an Italian business partner, is already in contact with Rete Ferroviaria Italiana, the company that manages the country’s national railway infrastructure, and plans for an Italian pilot project are expected to be announced in the coming months. Italy is not alone in showing interest, with Sun-Ways also having received government approval for a similar installation in South Korea, while discussions are reportedly underway with companies and rail authorities in France, the Netherlands, China, India and Singapore. France’s national rail operator SNCF, which describes itself as the country’s largest electricity consumer and second-largest landowner, has already signed its own cooperation agreement with the Swiss company as it works toward a goal of meeting a fifth of its energy consumption through solar power by 2030.
What still needs to be proven before widespread rollout
Despite encouraging early data, Sun-Ways and outside observers agree that there is still a lot of testing left before the solar railway can be considered a proven, scalable technology rather than a promising experiment. Regulatory approval itself has proven slow, with Sun-Ways founder Joseph Scuderi noting that it took almost three years to gain approval in Switzerland alone, and he has called on regulators to create a dedicated sandbox that would let similarly innovative infrastructure projects be tested more quickly while formal rules are in place. Countries like Japan and Indonesia have said they are watching the Swiss trial closely, but want more long-term data on maintenance costs and safety before committing to their own projects, a cautious approach that suggests the real test for solar railways will be less about whether the technology works, and more about whether it can be scaled up economically across larger and more heavily used rail networks found elsewhere in the world.