
The Crazy Genius Behind Solar Roadways - sethbannon
http://techcrunch.com/2014/05/25/the-crazy-genius-behind-solar-roadways/
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danpat
The creators were answering questions on Reddit here:

[http://www.reddit.com/r/IAmA/comments/1042mm/solar_roadways_...](http://www.reddit.com/r/IAmA/comments/1042mm/solar_roadways_amaa/)

The summary seems to be "we've got this awesome idea, and lots of money, now
we're going to try to see if it will work."

The engineering consensus seems to be that it won't, or at best, will have
extremely limited applications. Everybody would be far better off putting
high-efficiency solar panels on rooftops than low-efficiency ones on the
ground where they'll get dirty and broken.

Reading their literature, there seems to be a great big gap where any kind of
decent engineering analysis would be.

While I can see the appeal of the idea, unicorns and hyperspace drives would
also be pretty cool. I have my doubts.

~~~
worrieddot
The engineering consensus or the naysayers consensus? It's all too easy to
tear apart ideas on the Internet, which is a shame.

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bronson
Engineering consensus. The math doesn't pass the smell test, not without some
incredible materials breakthroughs.

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drjoe047
Snake oil. Seriously. Melt snow in northern climes? Think about it. IF there
were enough sunlight to melt snow, why didn't the sunlight just, you know,
melt the snow? Are they THAT much more efficient at absorbing the sun's
energy? I don't think so.

Cost to buy, cost to install, cost to maintain, ... the economics just don't
make sense.

~~~
danpat
Their snow-clearing literature says that they'll pump energy into the grid
when possible, and suck it out for snow melting. Clearly a net-loss for
snowmelt operations.

All the other obvious problems aside, it _might_ be an interesting analysis to
see if there would be sufficient yearly yield to offset snowmelting operations
in winter. Snowfall is not constant, so "melt" operations might only need to
run for a handful of days per year, depending on the location.

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MichaelApproved
> it might be an interesting analysis to see if there would be sufficient
> yearly yield to offset snowmelting operations in winter

There doesn't need to be sufficient yearly yield. This isn't just trying to
pay for itself by collecting electricity on clear days to melt snow. It'd
still be a great solution if it uses far more electricity than it collects
because it's competing with _snow removal trucks_. If it could be cheaper and
more efficient than having trucks driving around dropping salt and plowing,
it'd be amazing.

Even if it's a little more costly, the ability to keep all the roads clear,
all the time, would be incredible and worth some added expense. Think about
how much safer the roads would be if they could remain free of snow.

~~~
danpat
The energy costs of melting snow are huge. It's done frequently for small
areas (private driveways, parking lots) where cost efficiency isn't a concern
(the wealthy) or where heat energy costs are very low (geothermal sources,
i.e. Iceland).

To do it on a wide scale would require ridiculous amounts of energy. I
guarantee that nobody would be prepared to foot the bill for that, and these
solar panels are highly unlikely to produce even a tiny fraction of the amount
of energy required, unless you amortize their production over a longer period
and store it somehow.

Unfortunately, it's not just a "little more costly", it's massively more
costly, to the point where it's just not a good idea.

[http://www.concretenetwork.com/concrete/snow_melting_systems...](http://www.concretenetwork.com/concrete/snow_melting_systems/costs.htm)

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letstryagain
This is a 'feel-good' idea but it's just a waste of resources. Why not build a
good road and a good solar panel separately? Combining them like this makes
for a very expensive solar road that's bad at being a road and bad at being a
solar panel. It's not like we're short on space to put solar panels, and
maintaining roads is already expensive enough as it is.

A waste of time and money.

~~~
joelrunyon
Not even worth trying? It seems like a smart enough idea to at least test out.

~~~
danpat
Road engineering is a pretty mature discipline. If this idea can't pass some
of the basic known challenges in a thought exercise, why bother testing it?
For example, they have no explanation as to how the tiles will be adhered to
the surface. Silica has poor adherence to asphalt in wet conditions, and
silica can react poorly with alkyds in portland cement. Both of those are big
hints that it might be impossible to stick these tiles down for their claimed
20 year lifetime.

~~~
joelrunyon
Seems like the best way to figure those issues out would be to start actively
using them to discover the areas where the feature set starts to break down.

~~~
atomicUpdate
What's your plan for when they fail, because we skipped the lab testing phase?
Don't forget, a failure will likely include multiple cars in a collision on a
faulty road surface (10's of thousands of dollars in damages and risk of loss
of life).

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andrewfong
I expect these will show up in parking lots long before before they end up on
actual roads or other paths. It's much easier to block off a section of a
parking lot for installation, repair, cleaning, etc. than it is to block a
section of a road. Also, parking lots tend to be privately owned.

~~~
icegreentea
Honestly, the first thing to do is just to put up solar panel roofing over
every exposed air parking lot. Everyone already wants the shade anyways.

It's honestly so weird that we're attracted to all of these 'crazy' schemes,
while skipping out on the all sorts of far lower hanging, and sensible fruit.

From an energy generation point of view, this plan is pretty irresponsible.
Solar installations have a relatively poor EROI as it is (for standard
installations) for mid-latitude regions. Purposefully handicapping your solar
infrastructure by putting on the road surface is particularly braindead in
that respect. From a systemic view, it makes more sense to rip out the solar
panels from the road way, and put it ontop of buildings, or really any where
you won't get random occlusions, and ridiculous amounts of dirt.

I mean, I get the attraction of easily reconfigurable displays on your road
surface, but honestly, the intelligence and power generation aspects of the
idea should just be decoupled, and split out.

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Ryel
Just out of curiosity...

What are some of the sensible, low-hanging fruit you have in mind?

~~~
letstryagain
Solar panels on roofs of buildings

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cheald
It's an interesting idea, for sure, but I just don't see how it makes any
sense at all for roadways, where the tiles will be subject to constant stress,
grime/dirt (which will reduce the already-not-great efficiency of PV cells),
non-constant sun exposure, and prime opportunity for theft. We have _lots_ of
not-yet-utilized solar space already that won't be subject to the downsides of
this kind of technology. Frankly, it seems like a solution in search of a
problem to solve. Also, they've got to be a _hell_ of a lot more expensive
than asphalt.

I can _totally_ see this as a technology for building patios and sidewalks on
privately-owned land. It would be really cool to have self-lighting pathways
that also serve to generate power for my household, but in terms of sheer
economics, it's going to be hard to make the argument for a lower-efficiency,
higher-install-cost solar brick than to just slap a PV array on my roof.

~~~
atomicUpdate
> It's an interesting idea, for sure, but I just don't see how it makes any
> sense at all for roadways, where the tiles will be subject to constant
> stress, grime/dirt (which will reduce the already-not-great efficiency of PV
> cells), non-constant sun exposure, and prime opportunity for theft.

This is the part I don't understand...do people not realize how dirty roads
are? How often will street cleaning need to be performed to make sure they are
collecting enough power for just the LEDs? How are they planning on handling
all of the leaked oil/coolant/etc.? How many cans of spilled paint (accidental
or otherwise) will it take to bankrupt a city's road budget?

People are willing to risk their lives to steal copper wire...how are they
planning on securing every hexagonal foot of road in america when they're each
worth $1000+?

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SilasX
The crazy annoyance of linkbait titles.

