Place PV between and on railway tracks — removable panels or solar sleepers

Mechanism

Two sub-variants share the parent logic but differ mechanically:

• Removable inter-rail panels (e.g. Sun-Ways): pre-assembled PV modules laid flat in the ~1 m gap between rails by a track machine, clamped in, and removable in minutes for maintenance. Retrofits onto existing track without altering the trackbed.
• Solar sleepers (e.g. Greenrail): PV integrated into replacement railway ties/sleepers. Not removable; requires swapping sleepers.

Generated power feeds the grid, stations, or traction current.

Why it may beat road-surface PV

Rail corridors are linear, publicly owned, already sealed, and often near constrained grids. The failure modes that sink road-surface PV are milder here: trains pass intermittently and roll rather than brake, turn, and grind continuously, so mechanical load is lower. Rail operators also have a direct decarbonization motive for their own traction energy.

Operating profile

• Inter-rail panels sit flat (same tilt penalty as roads) but avoid the traffic-load problem and, via removability, the maintenance-access problem.
• Reported/claimed yields: Greenrail 35–44 MWh/km/yr; between-rail systems ~0.1 MW/km (Bankset claim). Sun-Ways projects up to ~1 TWh/yr across the Swiss network (~2% of national consumption).

Honest limits

• Flat orientation still costs efficiency versus tilted arrays.
• Unproven at scale — debris accumulation, snow clearance in Alpine/continental winters, and long-term vibration fatigue are unresolved beyond pilot length.
• Grid integration — feeding single-phase traction current directly is technically awkward; most pilots feed the ordinary grid instead.
• Hype risk — Bankset announced GW-scale global plans that never visibly materialized; treat headline projections skeptically.