Conveniently, there's already an electric cable sized to transport a few MW nearby. This might reduce the cost of installation, also there'll be no land acquisition/impact study issues.

However, I agree that putting solar panels in between or near rails will increase the cost of maintenance: the technicians will need to travel longer times to the work site, and now they also need to be certified to work near railroads.

People hate the idea of solar in currently-unused space. Even if that space is bare desert. So you can get a big PR boost if you propose "solar, but on a thing" (roadways, water, and now trains).

Yeah, I can understand putting solar on things when it lets them become standalone off-the-grid setups but for something like railroad track it’s just not that much space and the costs are so much higher. Except on the tightest urban lines, just putting rows of normal panels next to the tracks should be significantly more space with much easier engineering.

friends of friends simply need all that sweet government grant money

They're getting 180 watts per meter, so it would take 50 km of panels to power one high speed train. And that's when the sun is shining. Double this at least if you want to store the energy and run trains in the evening.

> And yet it did work,

You can put panels on anything and generate power for a couple years.

This system was only 18kW. That’s less than what we put on some residential houses. They didn’t address any of the hard parts like a transmission system capable of scaling up along a linear row of panels extending kilometers long.

> Solar panels have gotten so cheap that it might not be as important to install them in perfect conditions, and other factors like real estate, ease of maintenance, access to the grid come into play in interesting ways.

They had to use special panels for this, not the cheap ones you know. Any installation in an area like this requires reinforced and protected panels, which are more expensive than what you’re thinking.

You did identify some of the problems: Maintenance on this is terrible. They’re not going to shut down train routes to fix problems with the solar, so when something breaks it’s probably broken for years until a maintenance window can shut down transpiration.

Access to grid is terrible. You can’t re-use the train power lines, so I guess we’re running new transmission lines? A linear array is the worst possible configuration for a solar array because it maximizes the transmission distance and starts to require high voltage equipment to work.

Would you ever think it would be a good idea if someone suggested we go put solar panels out in the middle of nowhere between towns? Or would you agree it’s better to put them close to the towns on unused space like rooftops where they can feed directly into local loads? I think the visual of putting these on train tracks is misleading a lot of people into thinking we’re getting something for free when really this is an absurdly expensive way to place and connect solar panels.

there may be solutions to it but there are just already existing places to put solar panels that don't even require coming up with solutions.

> seeing the train-car dropping the panels into place makes it clear that you have some immediate labor savings on the initial deployment.

Dropping panels in place is not the hard part. Getting all of that electricity back to a connection point is one of the many problems created by this idea.

Putting panels in a multiple kilometer long end-to-end row is very inefficient compared to rectangular layouts that can be clustered around connection points.

Placing a cover over the area between the tracks makes it much more difficult to inspect the ties (sleepers) and ballast.

With the added benefit of being able to mount the tracks at an angle, and the added disadvantage of occupying area near the tracks that is occasionally used for maintenance equipment.

And getting approval to widen the right of way, where it’s even physically possible, and issues around flora suppression.

Of course.

I have tried entrepreneurial stuff twice before, in my 20s, though without much success. Having ideas good enough to get investors interested is a sign that perhaps I should have another go at it.

Can you be wrong about your favorite flavor of jelly?

> Thankfully, Switzerland has lots of meters of railway.

The linear meters of railway are nothing compared to the square meters of rooftops. Putting panels in a long row is the maximally worst arrangement you can come up with.

> There's caternary on 99% of Swiss rail, every few dozen meters, that already transmits power.

I guarantee this wasn’t oversized to accommodate power transmission duties, too.

It’s also high voltage line. The solar setup would need additional and expensive high voltage equipment to interface with the line and to work within the design parameters of a line that was designed to deliver to the train, not carry extra power.

You could put the panels anywhere else and connect them normally to the grid like every other installation.

> There's caternary on 99% of Swiss rail, every few dozen meters, that already transmits power.

Switzerland runs on 15 kV catenary voltage. Transformers suitable for that kind of voltage cost a lot of money.

It's solar, of course the unit economics are going to pencil out positive in the majority of climates and energy markets. The real question is "why should we put them here instead of somewhere else."

I wonder if the benefits are legal/jurisdiction/political. The total amount of track they could install this on is huge, and it doesn't seem like something that will be disagreeable on the local level. It could just be the easiest place to put it to deal with property law and zoning etc.

Another political benefit is that it means work for a very large number of jurisdictions, as there are suitable tracks just about everywhere.

  Initially, he planned to remove dust from the surface of the photovoltaic cells using a cylindrical brush mounted on the rear of a train. “However, we realised that each time a train passes, it creates an airflow that sweeps away all the dust,” he said.

And all the train depots and train stations are already covered in solar panels, I presume.