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

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

#301

Post by dependsontheq »

reitzensteinm wrote: post #249
caymanjim wrote: post #225

This was not at all a failure. They built a 1km experimental road. They gained valuable information about real-world performance and technical challenges. It's not as though they built a 100km long six-lane highway with unproven technology. They built a tiny one-lane trial to test a promising idea. It was overhyped by politicians, but what isn't? Maybe they even steamrolled over engineering red flags. That doesn't me…

The trouble with this viewpoint is that there are an endless number of things we could be trying, and it's more or less a zero sum game. The idea was terrible on paper, easily falsified by back of the napkin math. The same amount of money could have been spent on, eg, testing the commercial viability of smoothing out grid loads by making ice off peak for cooling.

There are different reasons to try things, this is worth trying because we have so many roads and using even a part of them for energy production would have an enormous impact.

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

#302

Post by jaclaz »

onion2k wrote: post #285
panopticon wrote: post #149

Earlier quoted context omitted.

Not OP, but I was curious: Let's assume a good solar panel yields 15 watts per square foot under direct sunlight. The DOT estimates about 1.5 million acres of interstate in the US. Without getting too complicated, let's assume we produce at our ideal wattage for 3 hours a day. Given our ideal solar panel, this is 2.94 billion kWh per day. Getting ideal conditions on a highway surface is unrealistic, so let's assume o…

There are 77,000km of interstate in the USA. ( https://en.wikipedia.org/wiki/Interstate_Highway_System ) There are 4,000,000km of paved roads. ( https://www.roadtraffic-technology.com/features/featurethe-w... ) That puts your estimate out by a factor of maybe 25 or more (depending on road width) if all roads are converted to solar. And that's before the other paved areas like parking lots. I'm not advocating solar ro…

Also, I would be preocupied by the ways to carry this hypothetically produced energy.

Right now we have either small "local" productions with "local " consumption (that works well as there is little distance to be covered) or "large" production concentrated on one site and with tension raised to thousands of volts to allow delivvery to the final user.

A "solar" road would probably make sense only in urban areas (where there would be other issues, like - say - shadow from buildings, less time of road free of vehicles, etc.) to avoid the issue of transporting the energy for long distances to the final users (or have a huge loss in the process).

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

#303

Post by zimpenfish »

Wowfunhappy wrote: post #182
mbrumlow wrote: post #157

Earlier quoted context omitted.

> That it currently do not work economically is the issue that the article showcase. It's more than that. We simply don't live in a world where physics is in favor for doing this. Many people have done more than back of the envelope calculations to show this simply was a non starter. Those (people who took money to build ) push this idea are either ignorant at best and dishonest at worst.

I do wonder if the concept could work on a sidewalk, given that they aren't being perpetually driven over by 3,000+ pound vehicles.

There's a solar bike path in Holland which did pretty well. Exceeded expected yield the first two years but then dropped back to slightly under.

https://en.solaroad.nl/wp-content/uploads/sites/2/prf1-ENG-S...

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

#304

Post by emj »

voxl wrote: post #296
reitzensteinm wrote: post #249

Earlier quoted context omitted.

The trouble with this viewpoint is that there are an endless number of things we could be trying, and it's more or less a zero sum game. The idea was terrible on paper, easily falsified by back of the napkin math. The same amount of money could have been spent on, eg, testing the commercial viability of smoothing out grid loads by making ice off peak for cooling.

Lets see the easily falsified napkin math then

EVblog has some great videos about how bad solar roadways are, starting in 2014, and a good recap video in 2017 https://www.youtube.com/watch?v=rpwx-8s1M38

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

#305

Post by crocal »

As a side note, falling leaves is one of the most dreaded problem in rail transportation. Not only does it obstruct things very efficiently, including the passage of light, but it also makes the rail surface very slippery, making it sometimes impossible for trains to actually brake using mechanical means. Much much worse than snow or rain. One sympathizes.

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

#306

Post by lorenzhs »

eitland wrote: post #298
Atheros wrote: post #271

Earlier quoted context omitted.

May I please read the real-world experimental data that will save other companies millions of dollars?

Go right ahead. Scientific papers are probably easier to access than anytime before. Start by looking for optimal angels for mounting solar panels. Last I heard, unless you have movable panels the only correct angle is where they catch most of the sun in the middle of the day.

1.) I think the OP was asking where they can find the insights obtained from this failed solar road test that would allow others to save money. Not general photovoltaics stuff.

2.) Angling solar panels is a more complex problem than you might have thought: https://www.eupvsec-proceedings.com/proceedings?fulltext=mun... :)

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

#308

Post by dredmorbius »

IshKebab wrote: post #292
dredmorbius wrote: post #196

Earlier quoted context omitted.

Median strips and easements are a possible siting location. Shade awnings over car parks another. The challenge with solar power really isn't sufficient area for siting. It's low-cost installation and low-disturbance environments which ensure long panel life and low maintenance costs. Solar panels have a useful lifetime of about 20 years, due to numerous degredation mechansims (it's not just one), from fogging of the…

The lifetime is better than 20 years. They produce 80% off their original power after 20 years but it's not like they stop working. Nobody would bother replacing them at that point.

Correct, in that the degredation is to about 80% of original rated life. Actually, checking on NREL's site, it looks as if there's been some improvement, with 25 years a more accurate estimate. https://www.nrel.gov/pv/lifetime.html

However the point remains that 20-25 years is the standard rated lifetime for planning and estimating purposes.

https://www.nrel.gov/pv/lifetime.html

http://www.nrel.gov/docs/fy12osti/51664.pdf

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

#309

Post by dredmorbius »

fencepost wrote: post #254
dredmorbius wrote: post #196

Earlier quoted context omitted.

Median strips and easements are a possible siting location. Shade awnings over car parks another. The challenge with solar power really isn't sufficient area for siting. It's low-cost installation and low-disturbance environments which ensure long panel life and low maintenance costs. Solar panels have a useful lifetime of about 20 years, due to numerous degredation mechansims (it's not just one), from fogging of the…

numerous degredation mechansims (it's not just one), from fogging of the transparent surface to cracking, glazing from dust and sand, hail impacts, broken circuits, etc. Hasn't a lot of research been focused around ways to capture incident light and focus it down onto the actual cell surface? Iirc a lot of that has been things like surface coatings but is there really a requirement that's such a surface actually be i…

A concentrating system isn't going to reduce the overall degradation -- yes, there's less critical surface, but it's weathered about the same as a nonconcentrating surface, and affects proportionately more generating capacity.

Or at least that's the theory.

NREL conduct longevity / degradation studies for numerous specific PV panel designs and products. Degredation ranges between about 0.5% and 0.8% per year, with an effective lifetime of 20-30 years.

Rough number, and actual results depend on specific siting characteristics and events. A tornado passing overhead, sandstorm, or very severe hail, may significantly negatively affect experienced lifetime.

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

#310

Post by DanBC »

thaumaturgy wrote: post #177
mettamage wrote: post #172

Hmm... Can we just applaud that people are trying something new? Or are we going to shoot it down because of pessimism? If you know so well what works, then do your best and make it happen or write a guide on how to do experiments that almost always lead to success. They didn’t fail fast, but they failed with relatively little costs. What is 5 million to the national GDP of France? It seems to me they were trying som…

Yeah, this is how I see it too. It was an experiment. It failed. Things were learned from deploying it into a real-world environment. This may contribute in some way to a future technology, as often happens. HN of course is full of people who are experts on every topic, so naturally there was no need to actually perform this experiment. They could have just accurately predicted its faults and performance from theoriz…

> Things were learned from deploying it into a real-world environment.

Nothing was learned.

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