Solar frickin' Radweg, Erftstadt/Liblar (Germany)

[nctnico]

Ok, so we can return to this question wen all the roofs are covered with solar panels.

No. As with any technology it takes time to develop and we have seen solar roadways are not easy to get right. So starting development of any new technology to allow dual space usage of space to integrate solar panels at the time where all the useable roof space is used will be way too late -if there is even enough roof space to begin with-.

[Marco]

They are impossible to get right next century, based on nothing else but common sense.

When we run out of roofs, we can start with walls, when we run out of walls we can start with HVDC links to more southern regions. Lets leave trying to grow fruit in the stratosphere till we run out of fruit near enough the ground you can breathe.

[Ranayna]

Whatever you do, a solar panel on a roof will *always* be more efficient than one on the floor.
First of all, obviously, there will not be people walking on them (except maybe for repairs)
They cannot be angled into the sun.
Keeping them out of range will also reduce damage.

Regarding roof space: I only found a study regarding this for Germany, in German.
https://www.ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/studie-100-erneuerbare-energien-fuer-strom-und-waerme-in-deutschland.pdf

According to this study, that is already 8 years old, there are about 2.845 square kilometers of area in Germany that are useful for solar panels. *Not* including free space that could be used for something else. Of this usable space, 1.200 square kilometers are roofs.
Using solar energy as part of an energy mix would require about that area...
Mind you, those numbers are eight years old, solar panels have gotten more efficient, and roof area has increased.

As long as you are not in an area with heavy snow, it is not all that expensive to build a roof over, say, a parking lot. It does not even have to cover the whole lot. Just an area the size of the pathways of the lot would be more efficient.

[PlainName]

Whatever you do, a solar panel on a roof will *always* be more efficient than one on the floor.

You are making a classic mistake in thinking that anything that doesn't hit the max numbers is useless. Things can easily be 'good enough' and successful, whereas perfection often doesn't make it onto the drawing board. Further, you concentrate  on a single issue and suggest that perfection in that one issue is the overriding feature. But in reality there are many competing aspects and good engineering is often finding the sweet spot between them all.

[Ranayna]

In what case is a significantly more expensive and at the same time significantly less efficient solar panel ever "good enough"? Heck, that "Solar frigging roadway" can hardly power it's own blinking lights.

And focussing on a single issue?

Less power efficience
More expensive to install
More expensive to maintain
Questionable as road surface

Sure, those issues are related, but not all the same.

[CatalinaWOW]

Ok, so we can return to this question wen all the roofs are covered with solar panels.

No. As with any technology it takes time to develop and we have seen solar roadways are not easy to get right. So starting development of any new technology to allow dual space usage of space to integrate solar panels at the time where all the useable roof space is used will be way too late -if there is even enough roof space to begin with-.

I'm OK with this line of reasoning as long as it is sold as an investment in the deep future.  Doesn't seem that is the way it was and is being marketed.

[nctnico]

Ok, so we can return to this question wen all the roofs are covered with solar panels.

No. As with any technology it takes time to develop and we have seen solar roadways are not easy to get right. So starting development of any new technology to allow dual space usage of space to integrate solar panels at the time where all the useable roof space is used will be way too late -if there is even enough roof space to begin with-.

I'm OK with this line of reasoning as long as it is sold as an investment in the deep future.  Doesn't seem that is the way it was and is being marketed.

Well... all new technology is being marketed as being ready next week nowadays. Take self driving cars as a different example. Some believe it will never happen but OTOH serious companies are pouring money into it. They have crunched the numbers and deemed it a worthwhile investment.

[PlainName]

In what case is a significantly more expensive and at the same time significantly less efficient solar panel ever "good enough"?

As a single example, you don't have a roof you can use. Maybe the owner tells you 'no' or you have to pay significant rent or there just aren't that many. That's just one thing, and there many be many others that need the accounted for.

[tszaboo]

Ok, so we can return to this question wen all the roofs are covered with solar panels.

No. As with any technology it takes time to develop and we have seen solar roadways are not easy to get right. So starting development of any new technology to allow dual space usage of space to integrate solar panels at the time where all the useable roof space is used will be way too late -if there is even enough roof space to begin with-.

Ok, let's look it a different way. Let's say, a Dutch company, siphoning Dutch public money, figures out how to do solar roads, that is efficient and durable. What then? The huge Dutch semiconductor facilities will spin up, and start making local waffers, fresh like stroopwafel? Let's just say, the Chinese dont copy the entire technology the first week, how are we going to benefit from this? The cheap dutch labor will create mass production, and beat chinese prices?

[nctnico]

Ok, so we can return to this question wen all the roofs are covered with solar panels.

No. As with any technology it takes time to develop and we have seen solar roadways are not easy to get right. So starting development of any new technology to allow dual space usage of space to integrate solar panels at the time where all the useable roof space is used will be way too late -if there is even enough roof space to begin with-.

Ok, let's look it a different way. Let's say, a Dutch company, siphoning Dutch public money, figures out how to do solar roads, that is efficient and durable. What then? The huge Dutch semiconductor facilities will spin up, and start making local waffers, fresh like stroopwafel? Let's just say, the Chinese dont copy the entire technology the first week, how are we going to benefit from this? The cheap dutch labor will create mass production, and beat chinese prices?

Ever heard of patents?  https://uspto.report/patent/app/20200336098

[tszaboo]

Ok, so we can return to this question wen all the roofs are covered with solar panels.

No. As with any technology it takes time to develop and we have seen solar roadways are not easy to get right. So starting development of any new technology to allow dual space usage of space to integrate solar panels at the time where all the useable roof space is used will be way too late -if there is even enough roof space to begin with-.

Ok, let's look it a different way. Let's say, a Dutch company, siphoning Dutch public money, figures out how to do solar roads, that is efficient and durable. What then? The huge Dutch semiconductor facilities will spin up, and start making local waffers, fresh like stroopwafel? Let's just say, the Chinese dont copy the entire technology the first week, how are we going to benefit from this? The cheap dutch labor will create mass production, and beat chinese prices?

Ever heard of patents?  https://uspto.report/patent/app/20200336098

The word patent doesnt translate to Chinese.

[Ranayna]

Then i would go somewhere else with my project. I can only speak for germany obviously, but it is large, and there are *many* roofs without solar.
Why would i spend ten times the money, for a system less than one tenth as powerfull and that lasts less that one tenth the time, than a properly designed system? And those orders of magnitude seem *very* generous. Economically, without subsidies, properly installed solar power is not earning you much money anyway, it's more about having to buy less power.

And I agree that perfect is the enemy of good, but at some point it is just not good enough.

Regarding the pictures of that bikeway: I find especially the first picture quite funny. Those guys were lucky that 2018 was a dry year in most of germany. Otherwise that corn would have been at least double the height than in the picture, leaving almost no direct sunlight...

[PlainName]

the Chinese dont copy the entire technology the first week, how are we going to benefit from this?

Do you care who supplies the petrol you use in your car? It's you that makes the journey using it. Likewise, the Chinese or someone may make cheap panels, but it's you that uses the electricity produced.

[vk6zgo]

In what case is a significantly more expensive and at the same time significantly less efficient solar panel ever "good enough"?

As a single example, you don't have a roof you can use. Maybe the owner tells you 'no' or you have to pay significant rent or there just aren't that many. That's just one thing, and t here many be many others that need the accounted for.

So, instead, the tax man takes your money, spends it on "solar frickin' roadways", with abysmally poor efficiency & durability, then the "private sector" charges you for power from conventional sources.

If you are renting, you could move, or if you own your house, you could, even with the miniscule yards common in many countries, fit a set of solar panels in your back yard which would still outperform the solar roadway.

[PlainName]

If you are renting, you could move

Boggle! Have you, perchance, drifted away from what this thread was about?

fit a set of solar panels in your back yard

Yeah, great plan - making your back yard more or less non-existent sounds really cool. Bummer if it's North-facing, but I guess you could always sell up and buy a new house, eh

This isn't about what you personally as a single concerned person could do (never mind whether you might want to). It's about what us, the entire community, could achieve. For every person renting somewhere else there will be someone renting the original place. Sell your house and someone has to buy it (and live in it).

[vanthome]

New coverage in a magazine in Germany with some recent information about the historical events around this masterpiece of German engineering:

https://kraut-zone.de/trust-the-soynce-wie-ein-solarradweg-zum-geldgrab-wird/

[SiliconWizard]

Not bad:

[FrankBuss]

New article about it from a few months ago:

https://www.ksta.de/region/rhein-erft/erftstadt/erftstadt-solarradweg-in-liblar-zerbroeckelt-stadt-will-rueckbau-548556
(you can read it with free registration)

Image from the article:



In the article: The city plans to dismantle it, because it gets dangerous for bikes. The Solmove boss Müller-Judex is cited: it is the fault of the city. He has offered a repair and maintenance contract, but the city didn't answer.

I was there today. Looks like they removed all shards. But more of the protective layer and foil is removed. I don't know if people pries it off, but I guess it is just erosion, it disintegrates itself:

[tszaboo]

So 20-30% of the tiles were broken in just 3 years time 

[SiliconWizard]

Hilarious. (If it wasn't wasting public money.)

[Marco]

More of these companies should try to get into the only real market for solar tiles. Rich people gardens and private foot paths. Bike paths and public footpaths need to be designed for heavy traffic, it's just a fact of life. The amount of material you need to protect against heavy traffic combined with the longevity needed for a road surface makes this then an instant fail when the solution needs to be actually economical against lower hanging renewable energy fruit. Private installs on the other hand will not generally see heavy traffic and are a feel good luxury which don't need to be economically competitive.

Just spend a little bit of that scam money on something viable, then there will be something to sell after the bankruptcy.