Solar rail could become common in Europe after successful trial in Switzerland

Overall reaction

• Mixed response: some find “trains + solar” exciting and like using underutilized space; others see it as another “solar roads”‑style gimmick.
• Several commenters stress that a successful small pilot doesn’t prove large‑scale viability.

Engineering & maintenance concerns

• Panels between rails complicate inspection of sleepers and ballast and may interfere with drainage.
• Track ballast is periodically replaced; that would require removing and reinstalling panels.
• Safe access for maintenance near active rail lines is a major cost and scheduling issue.
• Risk of damage from derailments, debris falling off trains, and oil/grease contamination is noted.

Cleaning, durability, and performance

• Pilot claims that airflow from trains blows off dust; some think that’s optimistic, especially with sticky pollen or lubricants.
• Others note rooftop panels tolerate quite a bit of dirt with limited performance loss and are largely robust.
• Flat, horizontal mounting is less efficient than angled panels, and Switzerland’s winter solar yield is low.

Economics & grid connection

• Key open question: cost per watt vs normal ground‑mount or rooftop arrays.
• Several argue linear arrays along tracks are electrically inefficient; long cable runs and high‑voltage interfacing add cost.
• Leveraging existing electrified rail infrastructure (catenary and substations) might offset some connection costs, but would require pricey transformers/inverters and was not addressed by the pilot.

Alternatives for siting solar

• Many argue there is ample “low‑hanging fruit”: rooftops, parking lots, industrial roofs, fields, and sound‑barrier walls along railways.
• Panels next to tracks or above parking lots are seen as more sensible than custom, reinforced panels between rails.

Ability to power trains

• Back‑of‑envelope math shows ~180 kW per km of track; covering all Swiss rail could in theory supply a meaningful fraction of traction demand but not all of it.
• Trains need power year‑round; severe seasonal mismatch in Swiss solar implies overbuild or large‑scale storage.

Policy, PR, and “snake oil” worries

• Some see this as clever dual use of land with political and permitting advantages.
• Others suspect it’s driven by PR, grants, and “solar gimmick” dynamics rather than engineering or economic optimality.