The first solar road has turned out to be a disappointing failure • Hacker News Board

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

#131

Post by makomk » Sat, Aug 17, 2019, 9:29 PM UTC

tzs wrote: post #45

close04 wrote: post #19

Earlier quoted context omitted.

The one in the Netherlands seems to be a 70m solar cycle lane. Cars will destroy a surface a lot faster than bikes. Maybe (dedicated) bike lanes would be a good place to start with this.

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.

Maybe the cyclists avoid the solar section. Remember, cycles are a lot less inherently stable than cars and provide much less protection in case of a crash, and glass is slippery. Even metal manhole covers get a little scary when wet.

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

#132

Post by einpoklum » Sat, Aug 17, 2019, 9:30 PM UTC

It was "unprecedented" in 2016 mostly because it was kind of a sketchy idea.

I mean, the road will get car-exhaust-sediment on it, like any other road; and all sorts of mechanical trauma. Roads wear down, after all, one way or another. Why have panels on the roads? Is there no land available in France?

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

#133

Post by mjevans » Sat, Aug 17, 2019, 9:30 PM UTC

agumonkey wrote: post #91

edoceo wrote: post #70

Earlier quoted context omitted.

Panels at the side of the roads?

panels above urban tunnels, maybe powering some air filtering system ?

You're on the correct track here.

My 5 min of reading the article and thinking about it idea is thus:

A slanted roof angled to shade and water/snow protect the road, shedding runoff in to a gravel area beside the road with drainage considerations accounted for. The far side might have some sort of attached tarp over part of it, and there'd be a gap between top of said tarp and the bottom of the panel roof. That would promote heat-stack ventilation along the underside of the panels and thus also SOME cooling.

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

#134

Post by reaperducer » Sat, Aug 17, 2019, 9:31 PM UTC

kolinko wrote: post #120

_Nat_ wrote: 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 actual…

I don't know how they do it in Poland, but in some countries when you flush a toilet on a passenger train going above a certain speed, the nasty stuff just evacuates to the space between the tracks.

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

#135

Post by onion2k » Sat, Aug 17, 2019, 9:32 PM UTC

TillE wrote: post #119

onion2k wrote: post #66

Earlier quoted context omitted.

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.

Sure, and above the road, and on the tops of buildings, and all over the place. Solar roads are a bizarre idea. The only point I was making in my post is that if all roads generated electricity they wouldn't need to be very efficient, so using that argument against solar roads is flawed logic.

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

#136

Post by close04 » Sat, Aug 17, 2019, 9:33 PM UTC

hanniabu wrote: post #32

close04 wrote: post #19

Earlier quoted context omitted.

The one in the Netherlands seems to be a 70m solar cycle lane. Cars will destroy a surface a lot faster than bikes. Maybe (dedicated) bike lanes would be a good place to start with this.

I think it'd be much better putting panels over roads. It uses pretty much the same footprint and it'll reduce the effect of roads being huge heat sinks they are.

This seems like a massive undertaking given that those panels would sit atop fast moving traffic and stand up to the elements (like tons of snow). But I'm sure at some point it will be perfectly feasible.

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

#137

Post by einpoklum » Sat, Aug 17, 2019, 9:33 PM UTC

jwr wrote: post #100

For some reason, solar roads are a very aggressive meme (in the classical sense of the word). They capture the imagination and blind people to engineering reality. Solar roads do not make any sense whatsoever, as you wrote pretty much any other place is better for panels.

How so? I mean, it's an image of cars driving over something which is kind of delicate.

Perhaps you mean roads with solar panels near them that feed the passing cars energy? Now that at least sounds exciting! (Although it's probably not a great idea either, not enough battery weight saving to be worth it.)

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

#138

Post by einpoklum » Sat, Aug 17, 2019, 9:34 PM UTC

edoceo wrote: post #70

dghughes wrote: post #26

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.

Panels at the side of the roads?

But then, why put them at the side of the road as opposed to, well, anywhere really?

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

#139

Post by beatgammit » Sat, Aug 17, 2019, 9:34 PM UTC

TillE wrote: post #114

taxidump wrote: post #101

Earlier quoted context omitted.

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.

Wikipedia[1], and probably most dictionaries, disagrees:

> A reservoir (from French réservoir – a "tank") is, most commonly, an enlarged natural or artificial lake, pond or impoundment created using a dam or lock to store water.

I've been to plenty of reservoirs with "lake" in the name, and I didn't realize the closest lake to my childhood home was a reservoir until I was a teenager, and the name didn't have reservoir in the name.

[1] https://en.m.wikipedia.org/wiki/Reservoir

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

#140

Post by _Nat_ » Sat, Aug 17, 2019, 9:43 PM UTC

reaperducer wrote: post #134

kolinko wrote: post #120

Earlier quoted context omitted.

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 actual…

I don't know how they do it in Poland, but in some countries when you flush a toilet on a passenger train going above a certain speed, the nasty stuff just evacuates to the space between the tracks.

Seems like any sort of solar panel on the ground is going to be prone to get nasty stuff on it.

I guess they might just have them at an angle, then trust the rain provide some light cleaning, while a street/rail-cleaner could go by for more thorough cleanings periodically?

I mean, I dunno what exactly their strategy is, but I'm assuming that they're not counting on a road to not get dirty. Cars leave rubber from their tires, drip oil, drop trash, etc..