Swiss solar panels between the rails still running, with SNCF watching

Lire en français : La SNCF suit jusqu'en 2028 l'essai suisse de solaire entre les rails

A 100-metre strip of removable solar panels between the rails at Buttes, in Switzerland's Neuchâtel canton, was still in service in late August 2026, 16 months after start-up. The Sun-Ways pilot runs until April 2028, with SNCF as a partner.

The installation went live on 24 April 2025 on a line operated by the regional transport company transN. It has 48 panels of 380 W each, giving 18 kWp and an estimated output of 16,000 kWh a year, according to Sun-Ways. A report by The New York Times, republished by The Boston Globe on 28 August 2026, described the pilot as ongoing and due to end in 2028. Valerio Tamellini, project manager at transN, told the paper: "This technology is rock solid."

A slow route to approval

Getting panels into the four-foot of a working railway took time. Switzerland's Federal Office of Transport (FOT) first turned the project down in summer 2023 for lack of technical references, then approved it after a review of about ten months, Solarserver reported on 2 October 2024. The approval came with conditions: Sun-Ways must run tests and measurements throughout operation to show that the infrastructure is not harmed, and installation and removal trials must prove the system fits around maintenance and line operations. TrainsNews was unable to consult the FOT decision itself.

Those conditions explain the design. The panels are meant to come out quickly when the track needs work, and Sun-Ways says a dedicated train can lay 1,000 m² of panels a day. Electrical connections sit inside the modules, and a cylindrical brush mounted at the rear of a train keeps the surface clean, according to the Keystone-ATS agency.

The economics remain open. Spread over the length of the pilot, the estimated output equals roughly 160 MWh per kilometre per year, on our calculation, against the 200 MWh per kilometre that Sun-Ways advertises on its home page for 400 W panels. Getting that energy to where it is needed is the harder part: researchers at the HES-SO Valais university of applied sciences are working on an electrical architecture to cut transmission losses, the NYT report said.

SNCF joins as an observer

France's national operator signed a collaboration contract with Sun-Ways in November 2025, announced on 2 February 2026. Its technology and innovation division and SNCF Réseau teams are studying the impact on maintenance, while the test programme covers panel installation, glare, track inspection including gauge measurement, maintenance compatibility, output and soiling, the SNCF Group said. At the end of the pilot, SNCF will assess whether to deploy such installations on parts of the French network, according to Venture Kick, the Swiss start-up programme that backed the company.

Other railways are looking at the same idea. South Korea's government has approved a two-year pilot on the Korea Railroad Research Institute's test track, the NYT reported. Sun-Ways lists new pilot projects in France, Belgium, Canada and South Korea on its website, without dates. For a railway, the test that matters is whether panels in the four-foot slow down routine inspection and tamping; that answer will come from the Buttes maintenance records rather than from the energy meter. Rail decarbonisation is also advancing on the rolling stock side, as with the battery train Metra unveiled for Chicago.

The pilot is scheduled to end in April 2028, when SNCF's assessment is due.

Sources: Sun-Ways, pilot page (accessed 01/11/2026); The New York Times via The Boston Globe (28/08/2026); Solarserver (02/10/2024); Keystone-ATS via Swissinfo (02/02/2026); SNCF Group (04/02/2026, updated 17/02/2026); Venture Kick (02/02/2026).

Photo: solar panels beside the railway north of Sandy, England, July 2015, for illustration. Christopher Hilton, CC BY-SA 2.0, via Wikimedia Commons.

Article written with the help of AI from the sources cited above, reviewed by the TrainsNews editorial team. Real photo, credited below the image. Spotted an error? contact@trainsnews.com – Our AI charter