A working railway in a Swiss village is also, quietly, a solar power plant. On 24 April 2025, Swiss startup Sun-Ways and regional rail operator TransN inaugurated what is described as the world’s first removable solar power plant installed on an active railway line open to regular traffic, on a 100-metre stretch of track near Buttes, canton Neuchâtel.
The timing is not accidental. Europe’s 2022 energy crisis sharpened the urgency for homegrown renewables, while land scarcity makes new solar farms increasingly contentious. Rail companies, by contrast, already own continuous linear corridors across entire countries.
How the Panels Fit Between the Trains
Sun-Ways slots photovoltaic panels into the railbed itself, held by pistons and removable in minutes.
Sun-Ways’ system places photovoltaic panels between the rails, resting on the sleepers and held in position by pistons pressing against the steel. A three-panel module, roughly 20 feet long, can be electrically disconnected and lifted clear in about 10 minutes by a single worker. The Buttes installation uses 48 panels rated at 380 W each, totalling 18 kWp across 104 metres of track, and is rated for train speeds up to 150 km/h.
Results from the first year of operation are straightforward. The installation has generated more than 16,000 kWh of electricity, withstood more than 11,000 train passages without a recorded safety or operational conflict, and experienced roughly one month of downtime from snow accumulation and integration work. Valerio Tamellini, project manager at TransN, put it plainly: “This technology is rock solid.”
Three Countries Are Now Watching
France, Italy, and South Korea have each moved to test or license the Sun-Ways approach on their own rail networks.
France moved first among international partners. In February 2026, SNCF signed a collaboration agreement with Sun-Ways to access performance data from Buttes, with the pilot running through April 2028 and covering glare, soiling, maintenance impact, and energy output. Nicolas Phan-Trong, SNCF’s head of energy and decarbonisation projects, stated the company’s position directly: “We want to become a big, big solar energy producer.” SNCF’s network spans roughly 20,000 km, and teams also noted a secondary benefit: the panels suppress trackside weeds, potentially reducing vegetation management costs.
Italy is moving through a licensing arrangement. Engineer and consultant Giuseppe Fulco has licensed the Sun-Ways design for an Italian pilot, estimating that deploying on 20% of Italy’s railways, around 3,000 km of track, could yield approximately 1 GW of generating capacity, enough to supply electricity to up to one million homes.
South Korea approved a two-year pilot in September 2025 at the Korea Railroad Research Institute’s test track, evaluating the technology under local climatic and operational conditions.
The Challenge Still Sitting on the Grid Side
The mechanical design has proven itself; the harder work now involves minimising electrical losses when power flows beyond the trains themselves.
The mechanical case is largely made. The harder problem is electrical. Sun-Ways founder Joseph Scuderi acknowledges that routing excess power beyond trains to the wider grid introduces transmission losses. Julien Pouget, a researcher at HES-SO Valais, is developing a specialised electrical architecture to reduce those losses. His team presented findings at a power systems summit in Paris.
What 2028 Will Settle
The Buttes pilot’s economics, assessed when the test concludes in 2028, will determine whether rail-mounted solar scales from a Swiss village to a global standard.
Rail companies already own the land. That removes the primary cost barrier: conventional ground-mounted solar requires roughly 2.5 acres per megawatt and is increasingly difficult to site. Sun-Ways estimates that full deployment across Switzerland’s 3,000-plus kilometres of rail could supply up to 30% of the country’s public transport energy needs. Tamellini expects the full economics to come into focus when the Buttes pilot concludes in 2028, a verdict that will shape whether similar deployments follow on rail networks worldwide.
