EEVblog #632 - Solar Roadways Are BULLSHIT!

[Koen]

Government-based entities own a lot of regular zero-cost surface area where normal panels would thrive. The french public railways own 12 million square meter of land plus social housing, schools, hospitals. They aren't short of exploitable land and rooftops.

[Kean]

Government-based entities own a lot of regular zero-cost surface area where normal panels would thrive. The french public railways own 12 million square meter of land plus social housing, schools, hospitals. They aren't short of exploitable land and rooftops.

Yes, but a lot of those are earmarked for other use and would have a book value.  The land used by roads probably don't.
I'm not trying to say this is sensible, just trying to get my head around how they could justify the expense, other than maybe trying to look like "innovation leaders".

[iaeen]

Government-based entities own a lot of regular zero-cost surface area where normal panels would thrive. The french public railways own 12 million square meter of land plus social housing, schools, hospitals. They aren't short of exploitable land and rooftops.

Yes, but a lot of those are earmarked for other use and would have a book value.  The land used by roads probably don't.
I'm not trying to say this is sensible, just trying to get my head around how they could justify the expense, other than maybe trying to look like "innovation leaders".

Trying to look like "innovation leaders" really is the only consideration for these people. People on this thread have already pointed out that we should first exhaust all other possibilities such as covering roofs and parking lots with conventional panels. Even then, we would be better off building conventional solar panels above the road.

[PlainName]

I'm not trying to say ...

Doesn't matter - you're toast now for letting even an inkling of a remote idea within several light decades of a brain cell

[Domagoj T]

It's spreading   
http://www.globalconstructionreview.com/news/frances-solar-roadw7ays-com7es-ame7rica/

[EEVblog]

So, I don't recall if this has been discussed here or elsewhere, but I was thinking that one way the proponents of these solar roadway schemes could actually justify the apparently terrible ROI is that they are also factoring in the cost of the land needed for equivalent solar farms, versus an effectively zero cost for use of the roadway surface area.

Governments usually have an awful lot of land and roof space. Government buildings, schools, hospitals etc for starters
Even if you paid some farmer to put solar farms on their land, it would still be orders of magnitude cheaper than building panels into roads and maintaining them.
As would subsidising people to put panels on their home rooftops.

It's no contest. Solar farms and rooftops have a lifespan in decades and are super cheap, reliable, and more efficient. Solar roadways is everything opposite that.

[LabSpokane]

Ha!  Solar Roadways blocked me on twitter!

Solar roadways apparently work better with no one to shine a light upon them.   

[f4eru]

https://www.rtbf.be/info/societe/detail_une-route-solaire-d-un-kilometre-dans-la-grisaille-de-normandie?id=9523186

Si l’idée séduit, notamment le maire du village de Tourouvre au Perche et ses habitants, la route comporte toutefois quelques inconvénients. Le premier est le bruit occasionné par le relief de la route. " C’est horrible le bruit. On ne pourra pas avoir des routes comme celle-là sur l’ensemble du territoire ", raconte l’un des commerçants du village. Ce témoignage est appuyé par celui d’une autre commerçante. " J’ai de la famille qui habite pas loin et du coup, on entend passer les voitures et ça fait quand même du bruit ", ajoute-t-elle.

-->The surface is much too noisy

" Ce n’est pas très parlant. Il faudra qu’il y ait une autoconsommation. On viserait évidemment l’éclairage public de notre commune, les bâtiments publics, les écoles et aussi les logements sociaux pour faire bénéficier les locataires de quelques dizaines d’euros par an ", explique Guy Monhée.

En fait, ce tronçon en panneaux photovoltaïques d’un kilomètre de long doit permettre d’alimenter l’éclairage public d’une ville de 5000 habitants.

Politics keep saying that it's equivalent to the lighting for a town. IT'S NOT ! Electricity cannot be stored at scale !!

Malgré quelques désagréments, la plupart des habitants se réjouissent de cette expérimentation mondiale dans leur petit village. " C’est toujours flatteur de se dire que la première route solaire est ici ", se réjouit une commerçante. " Je pense qu’on va avoir pas mal de curieux qui vont venir voir parce qu’à Tourouvre, c’est rare quelque chose comme ça ", espère une autre. Pour l’instant, la route a régulièrement été fermée pour cause de maintenance, selon certains habitants. Difficile donc d’y voir à l’heure actuelle, un vrai bénéfice. Mais cela ne fait qu’un mois que l’expérience a été lancée.

It attracts tourism. Yeah. That does not scale.
It was often closed for maintenance. Does not seem reliable either for a second shot ( after their 30m test on internal ground)

[PlainName]

Electricity cannot be stored at scale !!

No?

Pumped storage hydroelectric

[f4eru]

Electricity cannot be stored at scale !!

No?

Pumped storage hydroelectric

No.
This kind of massive thing can supply a part of the grid for a few minutes.

It is planned to hold about 500 MWh of energy, with a round-trip efficiency of 75%

Very useful, but not to scale as storage for day/night cycles, only for, like, 10 minutes.
And that's a very mature tech, with a limited and already mainly used up resource (usable mountain lakes).

So definitely no. It does not scale any more. it reached a point close to it's capacity limit long ago.

[johndoe123]

Sandpoint soon to be updated with newest panels

We were planning to surprise you all this week – we had scheduled to install the new panels in Sandpoint, but like so much of the country, we’ve been inundated with snow and ice. We even had a falling branch take down a wire on our property...ironic since if we’d had an SR Cable Corridor there, that live wire would have been safely in its “home” under the ground.

We decided to postpone the installation until it’s safer. Rain is predicted for next week – which should wash away much of the snow. One thing we have learned with our test location in our own parking lot is how difficult winter installations are. Replacing damaged panels is not a big deal, but we are thinking that in the future, we’ll relegate installations in snowy regions to the other 3 seasons.

In addition to making the replacement panels, Scott has used this opportunity to continue to work on software, firmware and hardware upgrades. So much engineering goes into SR technology. Scott is going to write a blog post after the panels are in to explain in more detail what he’s been working on.

the branch that delayed progress:
https://twitter.com/SolarRoadways/status/829171991190048768

[rrinker]

 Wait, we need their special technology to put the wires underground? There are MANY places here in the US where power, cable tv, and phone lines are ALL underground with no wires hanging from poles. I thought they built their facility = if so I'm sure they could have had their pole feed run into teh building underground, which was how it was at my old house. Poles along the street, but instead of a hanging wire feeding my house, it ran underground into my basement. It actually was an issue as I wanted to upgrade the service entrance capacity and that could have meant an expensive digging job, but as it turns out the power company ran all the feeds already sized for higher capacity so instead it was a matter of replacing the main disconnect and panel, no new run from the house to the base of the pole.
 My current house, it is an aerial cable feeding power. I'm careful to keep trees trimmed back to not overhang the wire, but my line passes right through a neighbor's tree so one of these days I know I am in for it, more likely from the rubbing wearing away the insulation than the tree actually falling.

[LabSpokane]

That's a twig. And that's not near their office in Sandpoint.

[drussell]

No.
This kind of massive thing can supply a part of the grid for a few minutes.
...
Very useful, but not to scale as storage for day/night cycles, only for, like, 10 minutes.
And that's a very mature tech, with a limited and already mainly used up resource (usable mountain lakes).

So definitely no. It does not scale any more. it reached a point close to it's capacity limit long ago.

The above linked installation is not really very big, the upper reservoir only holds about 9 million cubic meters of water, but that Wikipedia entry says it can run for up to 6 hours before it runs out of water if the upper reservoir was full.  It is normally only used for short periods of high demand but it can run for much longer.

Obviously pumped storage only works where the geography makes it possible, however it is a viable way of storing some solar energy for later consumption in some areas.

[PlainName]

however it is a viable way of storing some solar energy for later consumption in some areas.

Indeed, and I picked that one because it was the one that immediately (like after 2 seconds pondering) sprang to mind. There are larger systems that I didn't bother to find on wikipedia. And there are other technologies:

Molten sodium

[f4eru]

Obviously pumped storage only works where the geography makes it possible, however it is a viable way of storing some solar energy for later consumption in some areas.

It is possible to do it, of course. But it's not economically feasible, basically because it does not scale.


Molten salt is a possible alternative. But not scaled yet.

[lpaseen]

I just noticed that they finally put down the new panels - a few months late, and it's now 5x6 panels - all flashing
And the site that suppose to show energy produced - http://www.solarroadways.com/pilots  - accurately shows nothing.

[josecamoessilva]

I just realized that Solar Roadways doesn't go far enough!

They want to pave parking lots, right? So why not pave parking structures? Instead of a single level of solar panels, a 12 to 15-fold gain can be achieved by paving a parking structure. This would also have the advantage, especially in underground parking structures, of protecting the panels from rain and snow.

I'm a genius. Should patent this idea before someone steals it.

And, wait, there's more!

Solar Subways. Solar Tunnels. Solar Flooring (imagine the multiplier effect with all those floors in skyscrapers). Solar Bookshelves. Solar Storage Facilities.

The possibilities are endless.

[josecamoessilva]

Electricity cannot be stored at scale !!

No?

Pumped storage hydroelectric

No.
This kind of massive thing can supply a part of the grid for a few minutes.

It is planned to hold about 500 MWh of energy, with a round-trip efficiency of 75%

Very useful, but not to scale as storage for day/night cycles, only for, like, 10 minutes.
And that's a very mature tech, with a limited and already mainly used up resource (usable mountain lakes).

A little better than some local company that was flogging "gravity batteries" using rock counterweights, but still very far from the energy density of fossil fuels (and nothing like nuclear). BTW, my country, Portugal, uses its hydro as pumped storage to keep the coal-fired stations running at capacity during off-hours. (We have wind too, but it's a political thing, 100% subsidy-mining, zero value to the grid. Or so I'm told by former classmates who work for the national utility.  )

500 MWh = 1.8 E12 Joule, so at 42 MJ/l for jet fuel, this installation can store the same energy as 43 cubic meter of fuel; Given (it's been a while since I looked it up, heard this number recently) 60% chemical-to-electricity efficiency in a gas-generator combined cycle plant, say 72 cubic meters of jet fuel, say 2 to 3 tanker trucks. The only thing that beats fossil fuels is nuclear.

For the lulz, the locals here who talked about "gravity batteries" got an arithmetic bomb dropped on them: http://sitacuisses.blogspot.com/2016/10/gravity-batteries.html (I used 1980s combined-cycle efficiency. Because I'm old.)

[Brumby]

I just realized that Solar Roadways doesn't go far enough!

They want to pave parking lots, right? So why not pave parking structures? Instead of a single level of solar panels, a 12 to 15-fold gain can be achieved by paving a parking structure. This would also have the advantage, especially in underground parking structures, of protecting the panels from rain and snow.

I'm a genius. Should patent this idea before someone steals it.

And, wait, there's more!

Solar Subways. Solar Tunnels. Solar Flooring (imagine the multiplier effect with all those floors in skyscrapers). Solar Bookshelves. Solar Storage Facilities.

The possibilities are endless.

Think I'll get into the skylight business!

[ataradov]

It looks like this version lost the ability to display green color.

[EEVblog]

I haven't followed this for ages.
Who's cleaning off the snow?

[LabSpokane]

I haven't followed this for ages.
Who's cleaning off the snow?

As of now, the city of Sandpoint.  We're getting more snow today, but melting snow isn't really the point. When I get a chance, I will place another fruitless call to request net metering data.

[rrinker]

 These solar roadways are SO awesome they not only clear snow and ice from the panels themselves, but also from the surrounding area!

[moz]

It looks as though they should also produce power at night, given the light levels. I wonder if that's factored into the calculations