The Buttes solar railway and the Swiss technical reference

Until 2024, Switzerland had no technical reference to authorise solar panels between the rails of an operating line. Today there are 48 panels on 100 metres of track in Buttes, Neuchâtel, according to The Energy Shift video, with about 16,000 kWh a year estimated and removable modules.

Swissinfo reported on 11/10/2024 that the Federal Office of Transport first rejected Sun-Ways' request as a precaution and granted the permit only after prototypes and expert reports, for a three-year pilot with an initial budget of CHF 585,000. It was inaugurated in April 2025.

The open question is the time until the first revenue at scale. The regulator wants to observe fatigue, wear and maintenance before expanding, and the International Union of Railways flagged micro-cracks, fire risk and reflected noise. The 1 TWh a year potential is the company's estimate.

The pilot's output will be a set of wear data. If the regulator accepts it after three years, the rail network becomes generation space with no competition for land.