Ben's Website

Serious musings

Solar Trains < Solar Railways

When I first saw the headline "India's first solar-powered train makes its debut," I envisioned something that actually grappled with their substantial energy requirements and somehow leveraged their uniquely distributed infrastructure.  But, instead, the described pilot project puts solar panels on passenger cabin roofs for climate control.  So, small potatoes.

But recalling 2014's Solar (freakin') Roadways (mostly a bad idea), the better idea is to create solar railways, like:

Simply take the solar panels from the moving train and install them between the tracks.

I don't want to write a long post, so some bullets in favor of this idea...

  • generated power isn't moving, so it's easier to efficiently feed into the railway/municipal grid (the power density of liquid fuels is largely unrivaled by any sort of storage, so I'd bet it is better, on the whole, to optimize trains for the efficient use of energy than to dictate what source it comes from, let the electricity go to wherever it can be best consumed)
  • trains aren't made heavier from the panels, or substantially modified (though, given that most freight trains are diesel generator feeding electric traction, it would be cool if tracks had an electrified rail for mountain climbs and descents)
  • rights-of-way and site-prep are minimal, need only design the panels to flex with or be isolated from train deformations
  • panels are typically exposed to the sun along rural stretches
  • panels would be cleared of debris by the regular passing of trains and kept free of encroaching weeds/branches by the same
  • train-ground drag would be reduced by their smoother surface
  • a distributed source of power for many rural uses

and some limitations

  • panels are not angled to the sun (a Fresnel lens built into the glass protector could reduce losses with latitude)
  • total collection area is limited to very long, thin sections directly beneath or adjacent to the rail
  • these long, thin collection areas would require longer power transmissions than the same collection area would otherwise require (unless the rails themselves can be used as em waveguides--antennae--and efficiently)
  • the installation is not secured, theft/tampering more of a challenge than with other rail infrastructure

I'm sure I've missed some attributes, comment if interested.  I think the transmission issue is the most limiting, though while briefly searching about rails-as-waveguides, I saw this article about railway it says, this is so obvious I'm a bit amazed it hasn't already occurred.  So, maybe we can electrify rail corridors and install some generation in that developed but otherwise unused land; sure seems better than a few panels powering the AC.