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The first solar road has turned out to be a disappointing failure

sciencealert.com

111–120 of 349 posts

Re: The first solar road has turned out to be a disappointing failure

#111
post #97

This is not a fiasco, it is progress! I am sure they learned a lot. This is how science and engineering works. We keep forgetting that. Next time, I am sure they will do better.

It is a fiasco in the sense that it didn't work as advertised, or anywhere close.

Re: The first solar road has turned out to be a disappointing failure

#112
post #22

Fortunately we didn't give up on flight after the early airplanes. Maybe expectations need to be adjusted, but experiments like this are worth doing! We don't know exactly what they will lead to, but they often add to progress.

> Fortunately we didn't give up on flight after the early airplanes. Airplanes are not amenable to hackers designing them. Getting one to fly required a directed engineering effort, with a series of prototypes each targeted at solving a specific problem. I think it was the first such project that did so. The Wrights are often dismissed as "bicycle mechanics", but if you take a closer look they were very competent eng…

I would disagree. History is full of airplanes that were built or modified (sometimes improved) by hackers.

There's an immensely successful experimental aircraft industry, and I'm not just talking about people who are (successfully) building human-scale vtol drones.

Re: The first solar road has turned out to be a disappointing failure

#113
post #95

Earlier quoted context omitted.

Wouldn't you kill the lake, unless you only covered a small proportion of it.

Depends on the lake. There is a reservoir near LA covered in millions of black balls. Apparently this is a side effect of water quality regulation, direct sunlight triggers a chemical reaction that produces harmful byproducts. As a bonus, evaporation is also reduced, which matters in semi-arid climates like Southern California. https://www.veritasium.com/videos/2019/5/23/why-are-96000000...

If direct sunlight triggers a harmful reaction in your water, you need to reconsider what's in your water.

Re: The first solar road has turned out to be a disappointing failure

#114

Earlier quoted context omitted.

> Seems like you'd be much better off floating them on a lake. Right. Fuck the fishes, let them die, amirite? Landgrubbers unite, legs rule, fins drool!

I am unable to downvote but I would if I could. Many reservoirs are for municipal water supplies and not for marine life. It is common to cover them to reduce evaporation. To jump to the conclusion that floating solar arrays would "fuck the fishes" is obviously not well thought out.

A reservoir is not a "lake", by definition.

Re: The first solar road has turned out to be a disappointing failure

#115
post #45

Earlier quoted context omitted.

It's not obvious to me that cars will destroy a surface faster than bikes. Yes, cars weigh a lot more, but that weight is distributed over a larger area. The force on a given square millimeter of the surface that the vehicle is on is actually 2-4 times as high for a bike than from a car. This is why bike tires typically are inflated to 2-4 times the pressure of car tires.

It's not the point load, it's the total load. Which bends the road. Bending brittle things like solar cells cracks them. Movement of the car also causes compression waves to move through the roadbed. Roads need regular resurfacing because bending the roads constantly causes them to crack and crumble.

Also wider tires on cars are able to catch and drag small pebbles that add to the damage.

Re: The first solar road has turned out to be a disappointing failure

#116
post #3

“Cracks have appeared, and in 2018, part of the road had to be demolished due to damage from wear and tear.” as opposed to regular roads which never crack “the road was only producing half of the expected energy” - great, so just 2 km of a solar road could power the streetlights of an entire city the size of Tourouvre, 3700 people. We shouldn’t raise the white flag so quickly. I think we need a second iteration at le…

Road surfaces need the ability to flex while withstanding huge loads. Materials such as asphalt have this ability. Glass, in layers thick enough to support the loads necessary do not.

Bitumen can also be patched and repaired relatively quickly and easily, and can use relatively simple machinery to repair/replace large sections at once. Solar panels require a lot more surface preparation, precision joining and when they break (because they will - accidents happen), leave dangerous road surfaces that cannot be easily patched/repaired.

Solar Roadways won't work with our current state of technology where we need fixed rigid panels. Something that is either a replacement for bitumen, or can be mixed into it and is able to self-assemble a current pathway might be a viable option. But we're a long ways off doing anything like that.

Re: The first solar road has turned out to be a disappointing failure

#117

I never managed to see the advantages of having a solar road compared to just having a normal road with solar panels next to it. Or above it. Or literally anywhere else. In fact I can't think of many areas that still get direct sunlight that would make for a worse place to put solar panels than on the road...

I have serious doubts these experiments will lead to commercially successful implementations, but I don’t think it is useless to do them.

Reason? Solar cells keep getting cheaper and cheaper. That makes the costs of scaffolding to hold the cells take a larger and larger share of installation costs. In the limit where cells are essentially free, putting cells everywhere there is some large horizontal area will make sense.

Now, of course, we may not get close enough to that limit for this to make sense, cells may be too fragile for mounting in a road, there may be plenty of more profitable places to put solar cells, etc, etc, but that isn’t guaranteed, and we can’t tell without experimenting.

Re: The first solar road has turned out to be a disappointing failure

#119
post #66

Most solar panels are very inefficient at converting the sun to electricity so they need all the help they can get. Two things solar panels require is to be clean and to be perpendicular to the sun. A solar road achieves neither of those things.

Those things are necessary to get the opimimum amount of electricity but the point of solar roads is to sacrifice some efficiency for the benefit of having huge amounts of surface area. The amount of paved highway in developed countries is enormous, so even massively inefficient solar roads could supply all the electricity necessary and more.

If we're talking about highways, you can usually find large stretches of empty space immediately alongside them, at least the same width as the road itself.

Re: The first solar road has turned out to be a disappointing failure

#120
post #12

Solar roads seem like a really cool technology. Like, if they worked great and were affordable and everything, then awesome! But, practically speaking, they seem to violate the [single responsibility principle]( https://en.wikipedia.org/wiki/Single_responsibility_principl... ). By coupling a solar panel to a road, we're forcing the physical entity to comply with competing objectives. Seems like the future's prone to…

You know you kind of described how trains work? :)

I just did a quick calculation for Poland - we have 11k km electrified train tracks, with ~1.5m of space between the rails. If I calculated correctly, putting solar panels there would give us ~8-15tWh energy per year, which is 5-10% of the required electricity production for the nation.

I've never been a fan of the idea of solar roads, but solar railways might actually make sense...

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