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Power Week: Solar Roadways – Sci-Fi or Future Reality?

7/17/2014 12:55 PM EDT
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steve92
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Thank You!!!
steve92   7/17/2014 6:57:37 PM
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I have been an EE for a long time, receiving my BSEE in 1992, and have worked in engineering and engineering management at several high tech companies. The hype around this solar roadways thing has been unbelievable to me, because it is so clearly impractical. I agree completely with the "Bullshit" video, and any other EE worth his salt will too. Yes it does sound really cool at first, conjuring up images of these sparking roadways that provide this huge amount of power. But less than a minute of critical thinking clearly shows it is not a good idea, even if technically feasible. The cost to build and maintain vs the power output is not even close. This really does show that much of our society clearly has more money than brains and it saddens me. We have plenty of cheap desert space to put solar panels at a far better cost/benefit ratio. Putting them in a road doesn't improve that ratio, in fact it makes it far worse! Perhaps the thinking is that we don't have to pay to build and maintain roads (the government does), thus this would be free power. They are going to use solar power to melt the ice on the road! Well guess what? When there is ice the solar panels will not get any sun and won't make power! Not to mention that asphalt is actually more efficient than silicon at converting sunlight to heat (ever walk barefoot on pavement on a hot summer day?) Come on people, we can do better than this. Thank you for the BS video, it gives me hope that all is not lost.

David Ashton
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Re: Thank You!!!
David Ashton   7/17/2014 7:28:45 PM
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@Steve92 I was sceptical when I read this and it is nice to have this confirmed by someone far more qualified to comment than I am.  There are far better environments for Solar panels than roadways.  If you want power near roads, put the panels on nearby home roofs (angled better to catch the sunlight) and pay them a bit for the service.  Or in adjacent fields, and pay the farmers.  Who would pay for cleaning the cells on the roadways - they would rapidly get obscured by the dirt, tire rubber, etc that would accumulate on them.  Apart from roadways being a public space they seem to have few other advantages.

Duane Benson
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Re: Thank You!!!
Duane Benson   7/21/2014 12:17:29 PM
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Roof tiles would make a lot more sense. I think it's pretty easy to see that very little about the system makes any sense at all.

Even if the technology and economics were close to what would be viable, roof panels would still make a lot more sense. On a roof, you don't need to worrry about the surface neededing to hold weight, nor do you need to worry about the surface requiring traction.

mhrackin
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Re: Thank You!!!
mhrackin   7/21/2014 1:29:40 PM
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I'm surprised nobody has brought up the legal impediments for roof solar.  In my area (Atlanta) the building codes and the restrictions in nearly all HOA covenants explicitly forbid solar onstallations on roofs (for various reasons).  This may date back to the days when roof solar meant hot water heating (either pool water or domestic ho water supply) when roof loading and leakage risk were the primary reason.  The other mtoivation is esthetic, as a lot of the older technologies were fairly ugly!

David Ashton
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Re: Thank You!!!
David Ashton   7/21/2014 6:07:51 PM
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@MHRackin....have a look at Crusty's links below, the tiles he links to are really quite good looking - not much different from roof slates.  I know these are mostly used in the UK (from Welsh slate quarries) but there is no reason why the more usual roof tiles could not be built tlike this.    In Australia a lot of roofs (mine included) use tiles - usually cement ones.  A solar cell could be built into them without much trouble, I think?

rtapl123
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Re: Thank You!!!
rtapl123   7/21/2014 11:38:50 PM
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Why would you build high technology into a piece of rock?  You keep technology separate.

mhrackin
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Re: Thank You!!!
mhrackin   7/22/2014 9:37:24 AM
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@David Ashton: In most of the USA, the predominant roofing materials are shimgles.  In my subdivision, that is literally the rule (HOA covenants).  Even the color choices are limited to the ones originally offered by the developer.  There have been allowances made for some new styles ("architectural" shingles that look a bit like tiles, with a 3D aspect) that were not around 15 years ago when development began.  Tiles are mostly a Florida/California thing (Spanish-style barrel tiles).  Even there that's mostly for up-scale houses.

elizabethsimon
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Re: Thank You!!!
elizabethsimon   7/23/2014 6:08:53 PM
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I believe that you can also get "tiles" that look like cedar shake and possibly ones that have the look of the arcitectural asphalt shingles. It looks like you can get solar shingles tha tlook similar to the asphalt shingles but if the HOA is even specifying the colors that you are allowed to use, they porbably wouldn't pass (the pictures I saw they were significantly shinier than regular shingles)

Yet another reason to avoid neighborhoods with HOA covenants although it's getting harder to find...

 

Sanjib.A
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Re: Thank You!!!
Sanjib.A   7/20/2014 2:07:54 AM
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I too think that it was a wastage of money!! Totally impractical concept!! As you have correctly said, snow blocking the sun is one thing, dust and mud is another one. How is that protected against rain and storm? This is far far away from future reality and looks only Sci-Fi to me. I completely agree with the "negative feedback" video.

More that the solar roadways idea, I like the emblem on the guy's T-shirt saying "I always give negative feedback" with an image of an op-amp negative feedback circuit!! :)

  

AZskibum
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Re: Thank You!!!
AZskibum   7/20/2014 10:41:27 PM
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I'm curious what the $1M goal of the Kickstarter campaign was -- maybe just proposal writing? Clearly that isn't going to get you very far if actual solar panels are to be installed on a piece of roadway -- even a rather small piece of roadway.

krisi
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Re: Thank You!!!
krisi   7/24/2014 7:33:17 PM
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Yeap, $1M was needed to secure $1B that will be needed to make this reality

Doug_S
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Melt ice and snow?
Doug_S   7/17/2014 9:23:11 PM
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I'd love to see what material they hope to make these out of that they can stand up to a snow plow (since it can be cloudy for a week in winter and the sun is pretty feeble up north in late December anyway)

 

Not to mention how they'll hold up to salt, sand, and freeze/thaw cycles in the gaps between panels.

 

If you wanted to put them in a parking lot, I'd rather see them used as a ROOF over the parking spots so your car doesn't get 1000 degrees in summer and you're protected from the rain.  Probably cheaper to do that since you don't need special tough panels and more importantly if they're the parking lot THEY WON"T MAKE POWER WHERE CARS ARE PARKED!  Did no one think this through?  I guess if a company invents a way to make extra durable solar panels they have to think up a market for it...

prabhakar_deosthali
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Put the money in the right place
prabhakar_deosthali   7/18/2014 1:52:55 AM
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If they have funds to build such costly solar panel roads all over united states , why not put the same money in putting solar panels on all the house roofs free of cost.

I think putting solar panels on the roofs will cost much less to install and maintain and you will get much more energy than what has been estimated by the road netwrok, because percentage wise I think the road area will be a very small percentage of the roof area of all the houses, buildings alongside those roads.

 

dt_hayden
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Re: Put the money in the right place
dt_hayden   7/18/2014 11:17:47 AM
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We don't have the money to do that.  This outfit is just exploiting government funding and the idea will wither once the free money goes away. 

waaromikke
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Dreams
waaromikke   7/18/2014 9:13:00 AM
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If people are willing to invest 5B$ in a non-functional social network site (CYMK) then why not spend 2M$ on a non-functional solar project?

I agree with most of what is mentioned in the video. I almost feel ashamed/embarrased that an engineer started this project (a marketing person... yeah that sounds plausable).

dt_hayden
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bovine excretement
dt_hayden   7/18/2014 11:16:20 AM
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Of course it does not make financial or practical sense.  When I saw an article on these folks a few years ago in our local paper (these folks are up north in the same state), I also cried bovine excretement!   The level of hype on so many fronts is a warning sign in itself.   The proposal is not rocket science, if it made sense, it would have been pursued earlier and by more people.  These "inventors" are riding the wave of government funding (and now apparently crowd funding) and are obviously passionate about the possibility of becoming obscenely rich off such a large scale project.  The saddest part is the engineer on the project failing to examine basic limitations of his idea.

toney
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lunar cells
toney   7/18/2014 11:52:26 AM
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I am working on a Lunar cell to be powered from moon light.  I need some funding, crowd or federal, it won't matter.  I am sitting on a $6.00 office chair I bougth from a used items store this Am.

Embedded SW Dev
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Melting snow is unrealistic
Embedded SW Dev   7/18/2014 12:21:08 PM
I did a quick back-of-the envelope calculation a couple of weeks ago. In a severe snowstorm in the Chicago region, just in Cook County, if all the roads (excluding parking lots) were solar roadways, a 10 inch snowstorm would require over 2 hours of 45 TW of external power to melt the snow. Since they don't use solar (and couldn't when snow covered), that power has to come from outside the solar cell, and would require the full capacity of about 45 largish nuclear power plants. Their calculations apparently didn't include the latent heat to melt snow, but only observed that their panel was "warm to the touch" in cold weather. If one can't melt the snow, one needs snowplows and salt, which will ruin these solar cells. It even snows in Texas, and when it does, they usually need all their power to heat homes.


I also noted their calculation of providing 3x the power the US currently uses. They based their number on the amount of impervious surfaces, which includes roofs, so panels would be needed on every roof as well as every road, parking lot, and sidewalk, to provide 3x power.

I need to watch the video.

DrFPGA
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Re: Melting snow is unrealistic
DrFPGA   7/19/2014 6:51:38 PM
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Maybe they plan on melting the snow the old fashioned way. Use to power to charge batteries to run the snow plow..

HankWalker
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Dirt
HankWalker   7/18/2014 12:33:46 PM
If steve92 has been an engineer for a long time, then I guess I've been an engineer for a really long time. Without looking at any details of the concept, the obvious problem is dirt, oil, debris - the junk you find on any road. Melting off snow is laughable - you don't even need a calculator to see how that is completely unrealistic. The people donating to this could have donated to a revival of Reading Rainbow instead.

David Ashton
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solar tiles
David Ashton   7/19/2014 5:23:43 AM
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One wonders why these guys don't put their energies into making practical solar roof tiles.  Something compatible with an existing design or designs, easily connectable and installable.  Sure they would be more expensive than existing solar panels, but you could deduct the normal cost of roof tiles, which is considerable.   Does anyone know if anyone has done anything like that already?

Crusty1
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Re: solar tiles
Crusty1   7/20/2014 2:35:04 AM
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Hi David.

Why they do not insit on new build houses having solar I do not know. My pay back on an old property has been 4 years with subsidy or 8 without from a life of 25 years not bad.

Noe just ewant a good storage system. Solar tiles are available here

Try this link http://www.renewableenergysystemslimited.co.uk/products/solar-slate-traditional.

David Ashton
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Re: solar tiles
David Ashton   7/20/2014 2:59:58 AM
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Hi Crusty, thanks for that link.  Quick calcs - these give around 50 W / m2 as opposed to a sample 185 W panel I looked at which was nearly 150 W / m2.  So a fair bit less efficient, but very nice looking.  And depending on cost you could cover a lot more of a standard roof with these than with panels.

PS just reread the web page - they quote a peak output of 130W / m2, sounds high, I suppose the tiles overlap a fair bit which contributes a fair bit (only 35% of the tiles are active panel).  130 W / m2 is fairly respectable.

David Ashton
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Re: solar tiles
David Ashton   7/20/2014 3:12:53 AM
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Crusty - ref storage systems.  Friend of mine is about to build a new house and looked at a storage system.   5KW PV panels plus an 8 KWh (I think) storage for A$23K.  The array and inverter alone would be around A$ 7k.  BUT the storage means you are effectively saving 31C per KWh which is what the Electricity Co charges you, as opposed to the paltry 6c / KWh they pay you for feed-in.  He did his sums and thought it was worthwhile.  Its a Lithium battery storage and supposed to last 10 years.   If you got 25 KWH a day from the panels, and the storage system allowed you to use it all yourself, you'd save $28K+ in that time.  Doesn't sound like a very good return, though you'd be ahead a bit.  I'll ask him more when I next see him.

Crusty1
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Re: solar tiles
Crusty1   7/20/2014 4:42:48 AM
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Hi David, Yes was thinking could I get a crashed hybrid car, but the car breakers want more for the batteries than the car it's self.

I have a diverter on my inverter so that the export heats my hot water tank along with the solar water panel.

I must say I am pleased with the power output of my north faceing panels dull days they do better than the south facing panels.

All in all glad I bought in at the best subsidy time.

David Ashton
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Re: solar tiles
David Ashton   7/20/2014 5:24:27 AM
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@Crusty...."I must say I am pleased with the power output of my north faceing panels dull days they do better than the south facing panels."

I'm amazed, I would not have thought you'd get much from North facing panels in the UK...???

dt_hayden
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Re: solar tiles
dt_hayden   7/21/2014 2:14:31 PM
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Sharp used to have solar tiles, which I believe were to be used in place of typical asphalt shingles, rather than placed on top.  Those dissappeared from their web site a few years ago.  Now they are marketing "SunSnap" panels which have easier installation and integrated/available microinverters (EnPhase).  http://www.sharpusa.com/SolarElectricity/SolarForResidential/SunSnap.aspx

Sanjib.A
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Scary but most practical road block to Solar Roadways
Sanjib.A   7/20/2014 2:17:19 AM
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It could be scary to most of you, but the most parctical argument why the Solar Roadways will always be a Sci-Fi and never reality (at least in Indian context)...the "road" would get stolen if you do not keep guarding every 500 mtrs (or less) of the road!! How many guards you would need? :)

Sorry...just forget about it!

 

AZskibum
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Re: Scary but most practical road block to Solar Roadways
AZskibum   7/29/2014 12:31:00 AM
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Sanjib wrote, "the 'road' would get stolen if you do not keep guarding every 500 mtrs (or less) of the road!! How many guards you would need?"

Sanjib, that would be a problem in nearly every country. Keep in mind there are people in the U.S. who steal copper wiring because it's worth a few dollars. Imagine what stolen solar road panels would be worth to thieves!

DrQuine
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Solar roads - best applications
DrQuine   8/3/2014 6:39:19 PM
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I'm thinking that the best use for these materials is on roads / parking lots that get most of their use at night when there is no sunshine that would be shaded by the cars. They would also be best used in climates with lots of sun and little frost (in Connecticut we've not yet mastered paving roads with materials that can survive the winter). Finally, the segmented panels on highways will likely cause some road noise / resonance at high speeds that could be very annoying to drivers.

If the technology really works, is affordable, and is waterproof perhaps it should start being used on the rooftops of buildings and garages where the surface has continuous exposure to the sun and can avoid the stress of automobile traffic.

Regardless, it sounds like this will be feeding into the "grid" and not into batteries which would significantly increase the construction costs or inductive charging of cars (which would shade the tiles as they drove over.

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