Solar between the rails in Buttes, Switzerland

Solar generation on existing infrastructure corridors avoids competition for new land and shortens licensing. In Buttes, in the Swiss canton of Neuchâtel, the startup Sun-Ways installed 48 panels of 380 W between the rails of a 100-metre stretch of active track, totalling 18 kWp, with more than 16,000 kWh generated in the first year.

What is missing is a second source of supply. According to the SNCF Group corporate page published on 4 February 2026, the French rail group is studying the technology in partnership with Sun-Ways itself, which invented the removable panel, and the Buttes pilot runs until April 2028.

A single supplier for an infrastructure asset changes the contract. Without an alternative source of supply, spare part prices, replacement lead times and maintenance conditions are set by one party alone, and the railway operator carries the risk of unavailability throughout the concession.

The existence of a second qualified supplier decides whether solar between the rails leaves the pilot stage and becomes a contractable asset.