Solar Roadways - really

[mr friendly guy]

In an example of when the rule of cool tries to take on the rule of reality. Unfortunately I have a feeling reality will win. Since this is popular on crowd sourcing site indiegogo (its set the record) I feel its worth having a thread dedicated to this.

http://en.wikipedia.org/wiki/Solar_Roadways

Long story short, imagine if our roads were made out of solar panels which can supposedly withstand the stress of motor vehicles driving across them. These panels could (according to the company)

1. Produce high amounts of energy
2. Melt snow in cold environments
3. Installed LED lights could light up various signs, warnings (say when an animal walks across)

Actually you can just watch their youtube video https://www.youtube.com/watch?v=qlTA3rnpgzU

On Indiegogo they have already raised more than $2 million out of their $1 million target
https://www.indiegogo.com/projects/solar-roadways

They plan to first start off demonstrating it can work with a solar carpark (the inside road of the carpark will be made of these panels instead of asphalt)

Now I must admit I first came across this concept when I was watching a criticism of this on my youtube subscriptions. Firstly I am going to throw my fat in with the doubters for several reasons.

1. Given the vast amounts of surface area they plan to cover (ie all roads) obviously it will generate a lot of energy. But you have a few problems
a. Roads can get covered with muck, snow etc and its easier to simply put a panel on the side of the road if you are going to go down this route. A panel will be less likely to be covered in dirt than a flat road.

b. Even if these panels can withstand cars heavy trucks driving across, there is a risk they will be scratch with dirt as a car drives over them. Opaque panels absorb less sunlight than clear panel.

c. A flat panel absorbs less energy than one facing the sun at an angle, which is in turn less than a panel which can track the sun. This is simply physics. If you have the resources to make a ginormous solar roadway, why don't you just put panels on the side of the road as I suggest above, and get more energy. Or in the case of their trial carpark, just put a semi roof composed of solar panels angled so that its facing the sun.

2. The claim about melting snow is very dubious. A black substance absorbs much more energy than a clear one, thus asphalt roads already are hotter than solar panels and in cold weather they are insufficient to melt snow. Moreover you use 15% of that energy into the solar panel. Where does this extra energy come from to melt snow? You would have to transfer energy from some other source.

3. LED lights are not that easy to see in the day, especially when you aren't looking directly on top.

4. $$$$. The cost has been calculated in trillions. The company disputes this, but..... if you calculate the cost of regular glass alone to cover the area they want, its trillions. We haven't even gone into the LED lights and the REE needed for the panels.

5. Power transfer to the grid - going to be difficult with so many panels.

If anyone doesn't have doubts, take a look at this youtube video https://www.youtube.com/watch?v=H901KdXgHs4

[madd0ct0r]

1a and b are correct.
1c is technically correct, but the effect is massively overstated in the popular imagination.

2 is their workaround to prevent salk being sprayed on the electronics. the grid pumps energy into the roadway. stupid as fuck solution.

3. solvable

4. yup

5. power grid transfer - interesting. one friend in the sector reckons this is a good chance to build in electric charging for plug in vehicles. his personal dream is induction charging to charge them as they drive.
In terms of smart grids and everything, if we move to distributed renewables (and we really should) then this sort of flex-grid will need to be built anyway. there's research projects across europe looking into it, it's something that is expected.

that said, this project has been good for a reason (quoting my own facebook post):

You know what is really great about this project though? It works. Not in engineering terms, although Dave Purple argues it's a useful step towards a plug-in transport system. It works because it's convinced 46 thousand people to chip in $43 dollars each to raise over $2 million. As a project to raise money, it works really well.

All over America, there are company analysts looking at that campaign as proof of market. Not proof of feasibility, but proof there is a large market of people who want to see this happen. People who would buy solar panels, who would buy green electricity, who probably vote for the green candidate over the coal candidate. Just like gay marriage, it's nothing, nothing, whoah everyone suddenly agrees!

This isn't a green grid tipping point, it's not a emission free transport tipping point, but it's the latest peak in a series of little waves of change rippling out. Things are getting interesting.

[Darth Tanner]

We had a thread on this here years and years ago... they seem to have made little progress nor will they - its typical solar energy glorious future bull shit which is completely divorced from reality.

The entire scheme has more flaws in it than a Gary Glitter come back tour.

One of the major problems is solar energy is only cash positive because of comical subsidy, if you were rolling it out to this scale the cost of carrying the subsidy would bury the energy industry.

EDIT: Solar does have a place, but that is on roof mounts offsetting Grid use of the building... and even that is reliant on subsidy to be cost effective.

[mr friendly guy]

You know what is really great about this project though? It works. Not in engineering terms, although Dave Purple argues it's a useful step towards a plug-in transport system. It works because it's convinced 46 thousand people to chip in $43 dollars each to raise over $2 million. As a project to raise money, it works really well.

All over America, there are company analysts looking at that campaign as proof of market. Not proof of feasibility, but proof there is a large market of people who want to see this happen. People who would buy solar panels, who would buy green electricity, who probably vote for the green candidate over the coal candidate. Just like gay marriage, it's nothing, nothing, whoah everyone suddenly agrees!

This isn't a green grid tipping point, it's not a emission free transport tipping point, but it's the latest peak in a series of little waves of change rippling out. Things are getting interesting.

I never thought of it that way. I wonder how many of these people who would want to chip in to raise money for this project, would bother buying their own solar panels?

Just to blow my own trumpet my 1.5kw solar panels were installed around November of 2010 (that long ago). Up to May 2014 its produced 6106 units (1 unit = 1KWH) and I used 4676 units in that time. So I produce more than I use. It gets better. The original solar panel cost me $2302 with inverters and another $150 to connect to the grid so I can sell power. As of mid 2013 I had surpassed that. In fact currently I have generated $3043 AUD compared to the $2452 it cost to produce it. So far I had it cleaned once (they haven't actually billed me yet), but generally in only 3 years I have come out ahead. Panels have been known to work for at least 2 decades (and those were the early panels too) although at reduce efficiency. Its win win for me and the environment.

Now wouldn't their money be better spent on buying solar panels than you know, solar roadways. Plus there was a time when China was subsidising their panels. Let them subsidise I say, rather than us doing the subsidising. Its not like we produce much by ourselves, but then the Europeans and Americans will chuck a fit and ignore their own subsidies in other industries.

[Borgholio]

I've always liked the idea of a green roof. Using plants to help shade the roof area does look nice and the more green the better. Solar could be put on sloped roofs that are unsuited for plants, parking lots, and large solar farms that can be placed in the desert or other wide open.

[salm]

Wouldn´t it be cheaper and more efficient to simply build roof structures over roads and put the PV there? I mean, if you absolutely need to use the space the roads occupy.

[Darth Tanner]

Wouldn´t it be cheaper and more efficient to simply build roof structures over roads and put the PV there?

Until you have an unusually high load come through and remove all your solar panels.

[TronPaul]

I'd be really worried about reflective glare from solar panels if this came to fruition.

[Sea Skimmer]

if this had a shot in hell of working out economically they wouldn't need crowdfunding to get a mere 1 million dollars of venture capital.

[StandingInFire]

So many problems with this design:
1) The bumpy surface will make driving across it not as smooth of an experience as normal roads.
2) You are not gonna be able to melt all that snow away in cold climate without supplying lots of power to the system.
3) All the microchips you need relative to the surface area of solar panels drives the coast up a lot.
4) Dirt, roads aren't clean nor is cleaning them often a logical solution.

It's pretty much the opposite of what you are supposed to do as an engineer, Keep It Simple Stupid. Tying to tackle too many problems at once to make it bad at doing any of them well.
If you want more solar power, put up solar panels, far better performance for cost & space.
If you want heated roads, heat roads, be it with hot water pipes or whatever else.
If you want dynamic road markings, why do you want dynamic road markings? that induces a lot of potential for error, what if its cloudy or there is a failure in the electric grid, its already bad enough when street lights stop working think how bad it will be when the road markings disappear or worse get scrambled.

[salm]

If you want dynamic road markings, why do you want dynamic road markings? that induces a lot of potential for error, what if its cloudy or there is a failure in the

Dynamic street signs also have potential for error but they are very usefull to regulate traffic in cases of snow or impending traffic jams and they are widely used.

Dynamic road markings which also light the roads are actually being tested in the Netherlands and the UK. I think they have some potential but apparently need some more research:

http://www.bbc.com/news/technology-27021291

http://www.bbc.com/news/technology-27187827

http://www.bbc.com/news/uk-england-london-26273038

Until you have an unusually high load come through and remove all your solar panels.

Meh, it´s not like trucks ramming into bridges are a signifcant problem. And even if it were you´d just put a big concrete slab at the start of your solar roof to shield the PV. I think overloaded trucks are an easily solved problem.

But since there´s so much other space to place PV, like so many house roofs there doesn´t appear to be a reason to put them on/over streets.

[biostem]

The developers of this should start small - how much would it cost to retrofit a typical 2-car-wide driveway into these? Would they offer various types of these - like ones that are just solar collectors, with no other fancy features? What kind of guarantee are they willing to offer? Are they willing to license the tech out to 3rd parties?

The idea seems very promising, but I'm wary that it may not be able to live up to all the claims it's making.

Also, would the LEDs be bright enough to be visible in a very sunny day, as lane markers and such? What kind of security measures are in place to prevent someone from changing the markers or even stealing whole units?

[madd0ct0r]

that last one at least, they're talked about including gps locaters in each unit.

Sinc etiles have to talk to neighbours to track road markings, it also means theft or removal is spotted very quickly.

[biostem]

I also wonder how they handle spills or roadway fires. Additionally, as time goes on, things like tire residue and random road sludge would accumulate - I suppose they could outfit street sweepers w/ some sort of solvent or scraper to address that.

[Irbis]

Solar roadways? Huh, I wanted to post that for some time, though never got around to doing that. Now I see there is already a thread on it, though very recent, strange, I'd expect local SOLAR POWER crew to post it sooner

Anyway, the idea seems neat at first glance, especially seeing it sidesteps one of solar powers biggest problems, namely that we already need roads and installing solar panels there mitigates both falling deaths (quite common among panel installers) and the whole glass deserts issue. Unfortunately, when you run the numbers, turns out it's yet another 'sounds great, but only if you ignore reality' renewable project...

[InsaneTD]

Especially once you consider the amount of traffic in the average city, the shadow from a car would block a large hunk of the sun's energy.

[AniThyng]

Glancing out of my apartment window at the suburbs it looks like you'll get more surface area if you just mandated solar roofing rather than trying to pave the roads. Also, when there's the most sunlight actually hitting the road it is also the same time the most cars are on the road...

[madd0ct0r]

yup and yup.

it's funny, this project always results in people going - 'but roofing parking spaces and houses would make more sense'
If the SOLAR POWER CREW just said to cover everyone's roof then they'd be shouted down as expenive and ugly and impractical, but this way it's the other person who comes up with the idea

[Irbis]

If the SOLAR POWER CREW just said to cover everyone's roof then they'd be shouted down as expenive and ugly and impractical, but this way it's the other person who comes up with the idea

Um, no? It's ugly and dangerous, but it makes some sense. Some sense in the countries that do practice pointless, wasteful urban sprawl. If you practice modern really ecological buildings, ones reducing heat and land loss, 4 to 10 story apartment blocks, like new Swiss designs, you will sadly find out the roof is far too small for the generating power for occupants and you would need to cover sides too... And then you suddenly have problem of tall buildings sending blinding glares everywhere around.

Also, by SPC I mostly meant the two guys claiming that, like Linux believers, in 5 years solar will have 99% of market and it's time to close all other energy programs down.

[Borgholio]

The only ugly part of solar panels I have found is the scaffolding and bracing to hold the panel up. I don't see how that is a big problem given how you can design a green roof with plants to hide the bracing. The panels themselves can look pretty neat. Glares can be handled by angling the solar panels just right or applying a less glossy protective coating.

Regarding the power output, the goal should never be to power the whole building. That is just not possible given the shape of many buildings. The goal should be to substantially reduce the net power consumption of the city as a whole, by putting panels wherever you can. Cutting the energy needs of a city by 1/3 or more will still have a major impact on electricity production requirements and pollution.

[Me2005]

So, I took the time to read through the FAQ on the Solar Roadways site, and it seems like the goal isn't really generating loads of power from roads. It's doing something to get roads to pay for their costs, making roads more modular and easy to repair, and improving infrastructure by including it into one coherent system that is easier to maintain than each system is separately.

The problem is that the creators are arguing down other solar options rather than admitting that yes, it'd be cheaper to generate energy another way but that that isn't the point. From their own website, covering something like 50% of Ohio with solar cells would generate just as much energy as the roads would; roads which would cover basically all of Ohio if condensed into one spot. Moving that array to Arizona or another southern desert would generate much more power or could be even smaller.

Their other goal is using money that would be spent anyway building roads to build Roads 2.0. I think the best parts of the model, if it works in high-speed trials and durability and isn't significantly more expensive to build/install (or it offsets that cost reasonably), is the modularity. Broken panel/pothole? Just pop the panel out and drop a new one in, hole fixed to 100% in under an hour; as opposed to current road repair methods which are all just temporary patches until you resurface the whole thing. The next best are the 'smart-grid' features that provide distributed power, possible road-vehicle communications (and power transfer), and utility lines. Solar is way down on the list, and something I'd be considering phasing out completely if the cost:benefit doesn't play out the way they think it will.

The problem with that is that the best features of his road design are also only realized on large-scale implementations. Driveways and parking lots don't benefit from smart-grids (well, they argue that parking lots could reconfigure based on load, but some of the other features wouldn't matter as much), and owners don't need to make repairs often or worry about blocking traffic while making them. Some of the least-efficient parts of the road - solar and heating - would be easier, cheaper, and more efficient to implement on the small-scale as totally separate systems.

Unfortunately, they're focusing on small-scale implementation at first. Doing a full set of city streets (or major utility & traffic arterials at least) would better prove their technology I think. Perhaps they can get their tech working and approved and then start entering bids to see if they compete with regular road building costs.


Personally, I think building highway-sign like structures with cells on top would be the best option for vehicle-road communication and solar placement, but they rightly argue that that would be a separate cost to that of the road itself.

[K. A. Pital]

I prefer BIG NUCLEAR STATIONS, BIG DAMS and also BIG SOLAR STATIONS in the DESERT and HIGH SPEED RAIL instead of puny car.

Not interesting, the solar road. Smart road can be done a lot cheaper, without the PV extravagance.

[Me2005]

I prefer BIG NUCLEAR STATIONS, BIG DAMS and also BIG SOLAR STATIONS in the DESERT and HIGH SPEED RAIL instead of puny car.

Not interesting, the solar road. Smart road can be done a lot cheaper, without the PV extravagance.

I do agree; it's more efficient to to one big installation than a boatload of small ones, especially when the small ones are forced to operate at significantly reduced efficiency because of it. But the idea of using money that was going into a road anyway to build power capacity has some merit; assuming he can get it down to a reasonably comparable cost.

I disagree on high speed rail though. I don't think high speed rail can work effectively in my region (Western USA). Population density needs to be way higher first - you'd either need to make so many stops that it'd never make sense on short lines or spend billions+ building the thing long enough to get places just to have it still be slower than taking an aircraft. For reference, Oregon is roughly the same area as the UK, but has a population of ~3.5 million; and 87% of those drive wherever they go.

[Darmalus]

I disagree on high speed rail though. I don't think high speed rail can work effectively in my region (Western USA). Population density needs to be way higher first - you'd either need to make so many stops that it'd never make sense on short lines or spend billions+ building the thing long enough to get places just to have it still be slower than taking an aircraft. For reference, Oregon is roughly the same area as the UK, but has a population of ~3.5 million; and 87% of those drive wherever they go.

My understanding is that high speed rail is planned like major plane routes, between major cities with few or no stops between. Based on the trains I've ridden, I'd gladly accept a longer trip to not be packed in like a sardine and/or lower fares.

[Arthur_Tuxedo]

High speed rail in California has become everyone's favorite whipping post because conservatives have torn into it as government encroachment, boondoggle, etc. and the pro-rail people have done almost zero public outreach to counter the offensive. Unless something like Hyperloop pans out (IIRC they still need to solve the heat buildup issue), we will absolutely need HSR by the time it is complete, and if the project gets killed we will be majorly fucked in 20-30 years. We will either need to spend ~$400 billion expanding the highway system (vs $68b estimated for HSR) or build new airports, as the SF<->LA air corridor is already at capacity and cannot accommodate a significant increase in travelers. Either alternative will cost many times the price of HSR, and both are significantly inferior (or will be by the 2030's). Car travel is much slower and less efficient, while air travel will become significantly more expensive as fuel prices continue their long upward trend. Trains are also much quicker than planes to board and prepare, and a train station with its smaller footprint can be affordably located much closer to population centers than an airport, so an SFO->LAX plane's 1:10 hour flight time turns into a doorstep-to-doorstep travel time of 4-5 hours, while a HSR train's 2:20 hour travel time turns into 3-4 hours total.