Solar Freaking bike parking

[Siwastaja]

You also cannot assume the walked/biked on top of panels are as cheap as the rooftop ones.  You need significant support for the panel to not crack, done in a way that does not cause temperature changes (day vs. night in Spain) to delaminate the panel from the concrete basis.

With the economy of scales problem, the price must be staggering. Normal rooftop PV is pretty much cost optimized by huge volumes. It is designed to be strong enough to just barely survive the installer carefully stepping on it by maybe half of their weight. Combined with the instructions that say not to step on it this seems to be a good compromise.

Even if one could manufacture a stronger variant where you can walk on on regular basis with maybe just tens of % more materials, the cost will be much more than just tens of % because of NRE cost for niche products.

And/or, it actually does not survive because the engineering was not done to the extent it should have been because it would have been even more expensive.

[coppice]

The modules for this bike parking space don't see intense traffic. And it looks like these are well constructed including drains to divert rain water; this design clearly went through a few iterations. So for sure their lifespan is more than a few years. It would be interesting to figure out who is manufacturing the solar modules to get some actual data instead of wild guesses. Platio (for example) gives a 5 year mechanical and a 20 year performance warranty on their solar pavement products.

Does anyone have pictures of any kind of solar pathway or plaza surface that is in reasonable shape after even a year or two?

[RJSV]

   Wow, Nctnico !
   I STOPPED reading, instantaneously, when I read your injecting the term:
   CONSPIRACY THEORY.

Please read on:
   My usual is to read all, through to end of responses.   However, don't (you people) realize how stupid, or disingenuous you are, injecting your useful sound-terms, sometimes but not always ridiculous new terms, or sometimes political terminology stolen from what you view as 'opposition'...   Please realize you bring contention to the table, like a little kid.
   We see this, sometimes I wish, in contentious times, for a little more, er, skill in opponents.  But mostly all I see is the (already identified as stupid) attempts to 'smear', along with some word-codes.
   Quote:  "...where's your MATH, you math person...".
   O.K. I twisted your words a bit, sorry.

Response ?
(we maybe need a 'Politics and Green Politics' section here (no).

[RJSV]

And, oh yeah;  I just realized, attempt to twist this conversation, by characterizing critics as
   "Needing a TILT, to the system", as being the main flaw, when I don't see any previous argument to that.

[nctnico]

You also cannot assume the walked/biked on top of panels are as cheap as the rooftop ones.  You need significant support for the panel to not crack, done in a way that does not cause temperature changes (day vs. night in Spain) to delaminate the panel from the concrete basis.

With the economy of scales problem, the price must be staggering. Normal rooftop PV is pretty much cost optimized by huge volumes. It is designed to be strong enough to just barely survive the installer carefully stepping on it by maybe half of their weight. Combined with the instructions that say not to step on it this seems to be a good compromise.

Even if one could manufacture a stronger variant where you can walk on on regular basis with maybe just tens of % more materials, the cost will be much more than just tens of % because of NRE cost for niche products.

Well, solar pavements have been around long enough to collect some data on what works and what doesn't where it comes to wear & tear. Also volumes seem to pick up. According to consumer pricing from Platio, it looks like these modules should be around 80 euro each. I count around 30 tiles so that makes 2400 euro for the solar tiles.

[Nominal Animal]

According to consumer pricing from Platio, it looks like these modules should be around 80 euro each.

According to MAKING-CITY project at Groningen, each module generates "approximately" 53000/2544 ≃ 21 kWh/year.  Let's assume generously that they last twenty years, with efficiency dropping linearly to zero during that time due to scratches and so on.  It means that during their lifetime, each module generates (21×20/2) kWh = 210 kWh.  To pay back just the module cost, none of the infrastructure (like cutting the hole in the pavement/asphalt, digging the holes for the modules and wiring), electricity price would need to be 80/210 €/kWh ≃ 0.38€/kWh for even just the price of the modules to be covered by the electricity they provide.

Even if we correlate for the average sunshine hours between Madrid and Groningen, each module only generates 36 kWh/year in Madrid, corresponding to break-even electricity price of 0.22€/kWh.  Again, this only covers the price of the modules, not the installation; cutting into pavement/asphalt to embed the modules into will cost a lot.  Perhaps not as much as a bike shed or leanto, but at least 1k€ (amortized 33€ per module; cutting and digging into pavement/asphalt is slow and takes both manpower and tools), putting the cost-benefit calculation clearly into the negative.

(And we've not taken the price of the inverters or DC/DC converters and batteries or other infrastructure needed to use the electricity.  That stuff is expensive, especially if we count the full 20 year expected lifespan.)

As I said, it looks like waste of money to me.  At least a roof or lean-to would provide comfort during the few cold rainy days in December–February Madrid has, and shade during the many hot summer months and days.

[SiliconWizard]

Yes, it's a waste of money. As you noted, you don't even count all associated costs, and assume a very generous 20 years, which that'll never reach in practice.
You need to understand that the money is not lost for everyone though.

[Nominal Animal]

Yes, it's a waste of money. As you noted, you don't even count all associated costs, and assume a very generous 20 years, which that'll never reach in practice.
You need to understand that the money is not lost for everyone though.

Oh yes.  Entire taxpayer-funded careers will be based on this stuff, no doubt.  With kudos and accolades and opportunities to match.

Nothing new there, though.

[nctnico]

According to consumer pricing from Platio, it looks like these modules should be around 80 euro each.

According to MAKING-CITY project at Groningen, each module generates "approximately" 53000/2544 ≃ 21 kWh/year.  Let's assume generously that they last twenty years, with efficiency dropping linearly to zero during that time due to scratches and so on.

You keep assuming that scratches make the power output drop to zero but this is a false assumption. For starters: dirty solar panels have a slightly reduced power output like in single digit percentages. Lots of lamps have frosted glass (with millions of scratches) but this doesn't prevent the light coming from the bulb from entering your room. Also keep in mind that human eyes can only see a fraction of the spectrum the sun is emitting so looks may be deceiving. Some materials which block visible light, are transparent to infrared (which is also converted into energy by solar cells).

BTW: 21kWh per tile (35cm x 35cm) per year is not bad at all but likely optimistic. A 400Wp panel tilted towards the sun at an optimal angle, will produce around 25kWh/year given the same surface area (going by data from the solar panels on my roof).

[Nominal Animal]

You keep assuming that scratches make the power output drop to zero but this is a false assumption.

The 2019 heavy bike traffic tests in Krommenie, Netherlands, failed within weeks.

The bike path one can expect four year functional lifetime, until the tiles get too broken up to be safe.  The front courtyard of the campus building in Madrid is likely heavier traffic area than the Dutch bike test path was.

Thus, the 20-year lifetime, and the estimated electricity yields (as given by the project promoters, which seem to be extremely optimistic wrt. confirmed results), are ridiculously overestimating the module lifetime output; as in by a factor of two to five.

If I recalculate the same using Madrid vs. Groningen average sunshine hours, five year lifetime with no degradation, at the projects own estimate of electricity output, it still puts the break-even electricity price point here at 80€ / (5×36 kWh) = 0.44 €/kWh.  That is the figure we have now, from existing tests.

To declare the installation worthwhile, you need to include the price of the inverters, converters, batteries, maintenance, and physical installation; and there is no way this could ever pay for itself.  We know from actual data that rooftop solar panels generate twice the electricity compared to ground-based panels at the same surface area, so even if electricity prices were to skyrocket, it'd just mean more panels on Madrid's roofs, not that the silly ground panels magically become profitable.

Simply put, because of the rooftop vs. ground production difference, ground-based panels just do not make any financial sense.

I am not claiming that a lean-to or bike shed with panels on the roof could pay for itself, either; but that at least those would provide comfort for both rainy and sunny days, and the rooftop panels offset their cost.  It is the roof that is useful for bike stops, moreso than the electricity.  Putting the panels on the ground is just throwing money away, because it is so much cheaper and more productive to put them on an existing roof.

[nctnico]

You keep assuming that scratches make the power output drop to zero but this is a false assumption.

The 2019 heavy bike traffic tests in Krommenie, Netherlands, failed within weeks.

Well, new technology needs time to get to perfection. Rome was not built in one day. If you quit at the first setback, you'll never move forward. As a consultant, I've seen and been involved in developing quite a few products which went through many stages of complete re-design (mechanical and electronics) before the product was good enough. At a startup incubator at a university I visit every now and then they have a writing on the wall which says: 'I just found 10,000 ways this won't work'. Still, over the years quite a few 'multi-million euro' companies sprouted from there.

[Halcyon]

They could have just installed the bike "interface" the other way around, that way there is no need to ride or park on top of the panels.

[Nominal Animal]

'I just found 10,000 ways this won't work'.

That's not what I am saying *at all*.  I showed you some calculations using the figures given by similar projects' projections, and what is required for 'it to work'.  Then, comparing to smaller investment cost and double the output using the same surface area, just means it will never ever beat rooftop installations in cost-effectiveness.  But, my core point was, if you spend money on such projects, at least make sure it provides comfort for humans, instead of hoping it will be profitable (for anyone else besides the Green Transition -snake-oil pushing salesmen and shysters.

It is more like 'here are the faults in that design. You need to fix these before it can really work'.  Your reaction is the same as the shysters and green-wonk-pushers: Lalalalala!  I don't hear you!  You are a naysayer, a conspiracy theorist!  I reject your reality and substitute my own!  I need this to work, emotionally, so it must work!  It just must!  And you need to pay for it!

In your own words, 'there is a negative return on investment' when putting solar panels in the pavement.  Fix that first, then we can discuss.  Imagining transparent surfaces that can tolerate foot and bike traffic at temperatures varying between -5°C and +55°C (Madrid pavement) surviving for decades does not cut it, because such materials haven't been invented yet.  (Literally: even sapphire and diamond slate would chip starting at the edges.)

After that, we can discuss why anyone would do that as long as there is a square meter of unused suitable roof space available for the twice-as-efficient rooftop panels, at least when public funds are involved.  Shouldn't funds be used as effectively and profitably as possible, and not to fund some peoples' pet projects?  Limited funds and all.

[nctnico]

There is no valid discussion to be had when you compare apples to oranges. You can't compare prices between a mass product and a low volume product that is still at it's infancy. The first solar panels needed heavy government subsidies in order to be remotely worthwhile for the early adopters. Solar pavement is no different; a critical mass and technological readiness level needs to be achieved first.

I also disagree about the material problem you see. There are lots of places with glass elements in walkways / pavements which last for decades. For example to bring light in basements. https://en.wikipedia.org/wiki/Pavement_light

Edit: a topic nobody has touched so far is the actual reason behind using solar energy for charging the bikes. If the operator wants to use solar energy and / or wants to have their systems completely self-sustaining (as in not needing a grid connection) to make installation easy and flexible, then using the solar pavement tiles is the cheapest way to reach those goals.

[RJSV]

   Hey!   I appreciate monitoring the arguments here, sincerely, because they lay out various cost and construction details...that can be later referenced, even if just estimates, some of them.
Another reason is, I've lately acquired an interest in analysis, of basic opposing verbal debates, generally...in this world of 'fact checks' and re-factchecks, and 'fake' this and that..
It can be maddening, unless some balance can be employed....
   
   But first, what about the job itself, which is ultimately the 'Solar charging' services.  For that, we would want a basic count; of how many charging receptacles are there, along with how many (customers) get access, per day etc.
   Like, for example, say there are 8 stations, where they are occupied 1/2 the time, across a ten hour 'service day'.  What does that set of conditions use, vs. the solar power obtained.
   (Will users encounter a dreaded
'CHARGER DEPLETED' message, and how often ?)
Hopefully, of course, any excess charge could be coupled out, to help with power grid, generally.  (THAT, by the way would suggest that a grid-tie might deliver best cost, using supposedly green grid power ?).

But leaving aside some of the nasty questions there, the relevant question for the bike users is how often will the CHARGER DEPLETED situation annoy users....Never ? Then you've built too much capacity.
Sometimes (empty), then bike users have to figure some alternates, or just grin and peddle off.

   See how I started in, but much more involved with estimating, like what about the other 14 hours of day....Likely you would have 24 hours access.
   Even the argument that bike rack top covers are beneficial would relate, because the charge level dispositions relate to how many are even using the service / rack.
And even the rate of bike use comes into the formula, in any particular locale.  Yes I know the claim could be made that MORE bike use would occur....might.

[RJSV]

   Ok so now I've given some thoughts regarding approach to use or delivery of (the charging service) to ebike using customers.   But the arguments themselves deserve some scrutiny, albeit amateur.   I started down that road (no pun intended) upon reading the term 'Conspiracy Theories' being put forth, a heavily politicized term that, frankly has no legitimate place here!
   Unclear on that whole day's posts (Tuesday March 5).   But at any rate, some methods for taking bias out of analysis are helpful, and that just simply means study / measurement of a sort-of 'metadata' on the actual text (of each writer's arguments).
   Someone using terms like "You just following Dave"...and "You are caught up in conspiracy theories..." certainly don't contain any, 'real' arguments, scientifically.   But those type comments, bordering on 'Gas Lighting' the opposing people are telling;  The writer seems to want to control or limit factual discourse.
...more later...thanks

[cosmicray]

This paradigm also accomplishes one other objective ... it separates the flammable electric bikes from the conventional 2/3 wheel transportation. It does so in a way that is stealthy.

[RJSV]

   And so, coming across this use, of 'Conspiracy Theories' as an argument mechanism seems a bit bizarre, at first, until you've recognized that the whole discussion gets tainted by some sort of 'agenda'...and not an agenda being announced.
As a reader, I'm assuming one agenda is to keep the (solar panels) 'exposed'...and laughably I'm not meaning to the sun, but rather as a publicity item...Hence the rather displaced arguments AGAINST placing (panels) elsewhere.
   So, you can measure that sort of thing.   Like, for instance, how much argument space is taken, discussing costs and impediments for the exact, ground mounted proposal (covered in a cursory manner), vs. how much argument space was devoted to dismissing alternates like putting up a canopy.   Seems like arguments there went into more 'volume' of detail, including regulatory hassles, with 'permits' and 'zoning', plus an impediment labeled as "etc. etc.", which, I guess, implies that there are 'too many' downsides to including a bike rack 'canopy'.

   Now, bear in mind I'm no expert, here.   But I also noticed OP brings into play an argument that (critics) never even made, then proceeds to debunk it, as 'ridiculous';  that being some focus on the 'TILT' of panels.   In truth, the various critics never made THAT point...at least not yet, in the back and forth dialog.
Interesting, because that's a distracting dynamic...to argue against some point that hasn't even been brought up.

   "...just for the sake of getting the panels tilted...".

   I did see that brought up later, but even that got exaggerated / misquoted.  (I believe it was mentioned as a small advantage, but that was later).

Anyway, please excuse my amateur analysis, that is an attempt to avoid my own bias as well as anyone arguing against.   The idea is to use 'metadata' concepts, such as how much space used, what words get put into the other person's mouth, and what politicized terms get employed (conspiracy theories).
   Not to mention a lame use of attempted 'smear' on one critic...Like I've said, I ALMOST wish opponents were a little better matched, in debate skills, (rather than mud slinging attempts).

[Nominal Animal]

There is no valid discussion to be had when you compare apples to oranges.

After you called me a parrot and a conspiracy theorist?  Pretty sleazy of you.  I despise social games like that.  And I was going to send you a PM to encourage you to keep pushing against my claims, because it is the underlying reasons and calculations, and not just the conclusions or opinions, that matter, and we can learn from.

The relevant discussion is whether the construction makes sense.  It does not.  Even in the future, it will not, because rooftop solar is cheaper and yields twice the electricity at the same surface area at the same location, per actual measurements.

My entire point, as has been in other related bike solar discussions, was that at least a roof or a leanto would provide comfort, and thus have intrinsic value to everyone using it.  Putting solar panels on top of it will offset some of its cost, but is not the entire purpose.  One could argue that a fabric awning would serve the same purpose with minimal cost, and they might be right.  UV-resistant awning fabric itself isn't cheap, though.

Another question is how much does a covered bus stop cost.  They're ubiquitous here in Helsinki, with the sole purpose of providing a bit of shelter from people waiting for the bus, and to provide some ad space.  There are hundreds of them here.  Each is the size of a charging station for 6-8 e-bikes, with inside lighting in the roof, and three plexiglas walls, the smaller two of which are typically reserved for selling ad space.  I'm pretty sure there are ongoing tests to see if putting panels on top of these (even if just horizontal, keeping them invisible) is worthwhile –– not necessarily to have the installation yield a profit, but just offset sufficient costs in the long run so that it makes sense to do so.  If it does make financial sense, it means the price of erecting such structures (with solar panels) will come down, but more importantly, become stable and predictable, making budgeting and planning such easy: is spending X € for this worth the comfort of its users, considering how it will affect the compus'/city/street look?  The same for solar paving stones will always result in "well, maybe, but it would make more sense to spend that money on rooftop solar instead".

So, no.  When commenting on a single silly installation, I am not comparing "apples" to "oranges", nor "mass-produced" to "one-off".  I am also not parroting anyone, when I happen to agree with them on this subject.  And dragging in conspiracy theories into this is, like RJSV mentioned, just low.  You know being called a conspiracy theorist really ticks me off.

[Siwastaja]

It again boils down to the fact there are;

Top tier locations for panels, like South (North for Australians) facing rooftops without obstacles,
Second tier locations, like random bus stop roofs with some shadowing or inoptimal angle,
and shit tier locations, like inside a road

In optimum world, we would obviously fill those top tier spots and once done, go for the second tier. In reality, I can kinda sorta accept doing 90% first tier and 9.9% second tier and 0.1% shit tier installation, while the last one obviously is more for research.

All that is needed is to stop bullshitting about it. Installations that make no financial or environmental sense can be honestly discussed as being test projects. It sure is harder to get money for them, of course. Do it with your own money and everything's fine.

[nctnico]

There is no valid discussion to be had when you compare apples to oranges.

After you called me a parrot and a conspiracy theorist?  Pretty sleazy of you.  I despise social games like that.  And I was going to send you a PM to encourage you to keep pushing against my claims, because it is the underlying reasons and calculations, and not just the conclusions or opinions, that matter, and we can learn from.

The relevant discussion is whether the construction makes sense.  It does not.  Even in the future, it will not, because rooftop solar is cheaper and yields twice the electricity at the same surface area at the same location, per actual measurements.

My entire point, as has been in other related bike solar discussions, was that at least a roof or a leanto would provide comfort, and thus have intrinsic value to everyone using it. 

You know the saying: Don't attribute to malice what can be attributed to stupidity.
But there is an extension to that: Don't attribute to malice or stupidity what can be explained by math.

It is a false assumption to think the people who placed this bike charging station are stupid or misguided. I'm quite sure they made a thourough analysis on what is the most cost effective solution to meet their design goals. Which, judging from the pictures, likely include low cost and low impact installation. Maybe even without a grid connection.

What you and others keep pushing is the wish to put solar panels on a roof. But what is forgotten is that putting solar panels on a roof is a form of dual use where the costs of the roof are set at zero where it comes to calculating the ROI of the solar installation. IOW: you can't go around stating solar panels should be put on roofs in places where there is no roof because it makes no financial sense to erect a roof just for solar panels. Or assume reasons why there should be a roof while obviously nobody needs/wants one, otherwise there would have been a roof or structure already. At least be happy there are companies which invest in solar solutions that exploit other dual use scenarios instead of dismissing the idea off-the-cuff. I see no reason to do the latter at this moment as I have seen no compelling arguments (as in definitive proof) that it can't be made to work in a economically viable way. Or not using solar power is better in all cases.

And I do know being called a conspiracy theorist ticks you off, but refrain from terms like greenwashing, mystical government handouts (*) and so on. It ticks me off people can't just accept that governments do what the majority voted for so I will call that out. There is enough nay-saying already. Sure people can have reservations but stick to engineering & economics.

* As I wrote before I'm doing quite a bit of new product development and from a front-row seat I can tell that the mystical government handouts don't exist. Most of the money to put a product on the market comes from private investors or people's life savings if they really believe in their idea.

[RJSV]

Blahblahbla blahblah.   Wall of response I'm disinclined to unpack, at least not today.
   Are you a PAID agent, or similar ?

Because you've doubled down on similar BS, including debunking criticism that never happened.   Build a roof, for free ?   ?      ?
But, have a good day anyway, I'm just staying around because I've AQUIRED an interest in propaganda mechanisms, and no harm done anyway, in discussions generally.

[Nominal Animal]

It is a false assumption to think the people who placed this bike charging station are stupid or misguided. I'm quite sure they made a thourough analysis on what is the most cost effective solution to meet their design goals. Which, judging from the pictures, likely include low cost and low impact installation. Maybe even without a grid connection.

No, the track record of urban planning details indicates no such analysis is usually done, or it is based on figures obtained using the Harrison-Stetson method, i.e. invented off the cuff for the purpose.  What matters, is whether those making the decision will feel good about it or not; they're not spending their own money for it, after all.  Public pressure is a big factor, yes, but with a suitable salesperson/marketdroid/representative, you can sweet-talk purse holders into anything.

As an example, only ~ 33% of public large-scale IT projects in Finland actually produce a functional result.  Most go wildly over budget, and it is extremely rare, almost unheard-of, to hear of any kind of public project completed in time and under budget.

Here we come into the crux of the matter.

Today, it is extremely difficult to get funding for research that others are not already doing, regardless of the potential rewards.  Those who fund research, want the positive publicity associated with "being at the forefront of the research, researching what everyone else is researching too".

Publicity and appearance is what matters, not the results.

Like Siwastaja wrote, test installations is one thing, but marketing paving-stone solar panels just does not pass even a rudimentary cost-benefit analysis.

You can associate them with your own projects and how difficult it is to get funding for sensible test installations/projects/products, but it does not change the fact that this one here just does not make practical sense: the results are predictable, and much worse than envisioned or estimated by the project leaders.

People are not doing solar roadways because rudimentary cost-benefit analysis –– "off the envelope" calculations –– indicate it could be worth it; they're doing it because they can do the marketing, and pay themselves a nice salary and get Green awareness points and positive publicity while doing so, even though they already know the project will fail, and produce shorter lifetime, lower electricity yields, and pretty negative cost-benefit results.  Those just do not matter, because by the time it happens, the people have already reaped the benefits and continued on to other projects.  The project managers and politicians get very little to no pushback from these; negative results won't affect their popularity or careers at all.

These are done, because doing them makes both the purse-string holder politicians and civil servants look good in public, provide additional positive publicity, and pays good wages for the people doing these projects, all paid for by the taxpayer.  I resent wasting taxpayer money, because it is the reason for the financial state of Finland right now: we've got a bloated public sector with 55% of all workers getting paid by taxes.  Because nobody is willing to cut some of that pork fat off, we're having to cut basic social support instead, because those people don't make as much noise as the 10% of the workforce paid by taxes that have questionable job descriptions.  Even trying to limit political strikes –– those against the government, not the employers –– to just one day caused huge uproar here.  This shit needs to end.

[nctnico]

It is a false assumption to think the people who placed this bike charging station are stupid or misguided. I'm quite sure they made a thourough analysis on what is the most cost effective solution to meet their design goals. Which, judging from the pictures, likely include low cost and low impact installation. Maybe even without a grid connection.

No, the track record of urban planning details indicates no such analysis is usually done, or it is based on figures obtained using the Harrison-Stetson method, i.e. invented off the cuff for the purpose.  What matters, is whether those making the decision will feel good about it or not; they're not spending their own money for it, after all.  Public pressure is a big factor, yes, but with a suitable salesperson/marketdroid/representative, you can sweet-talk purse holders into anything.

As an example, only ~ 33% of public large-scale IT projects in Finland actually produce a functional result.  Most go wildly over budget, and it is extremely rare, almost unheard-of, to hear of any kind of public project completed in time and under budget.

Who says this bicycle charging system is paid by public/government money? Or that politics where involved?

A bit more Googling shows the system is likely from this Spanish company:
https://www.solumpv.com

And as I already assumed the company is funded through mostly private investors:
https://www.crunchbase.com/organization/solum-673e

You won't convince me all the investors are (run by) complete idiots.

[Zero999]

Just because it's privately funded, it doesn't mean it's viable or sensible. Look at all the crappy crowd funded products which have fallen flat. It means nothing. Ignorant investors will through their money at solar because it's cool and seen as environmentally friendly, irrespective of whether said project is any good or not.