Solar Roadways Get DoT Funding 484
mikee805 writes "Solar Roadways, a project to replace over 25,000 square miles of road in the US with solar panels you can drive on, just received $100,000 in funding from the Department of Transportation for the first 12ft-by-12ft prototype panel. Each panel consists of three layers: a base layer with data and power cables running through it, an electronics layer with an array of LEDs, solar collectors and capacitors, and finally the glass road surface. With data and power cables, the solar roadway has the potential to replace some of our aging infrastructure. With only 15% efficiency, 25,000 square miles of solar roadways could produce three times what the US uses annually in energy. The building costs are estimated to be competitive with traditional roads, and the solar roads would heat themselves in the winter to keep snow from accumulating."
Unsafe? (Score:5, Interesting)
Re:yeah right (Score:2, Interesting)
...Also why do they have to make roads out of them.. where did that come from? Just put them out on land somewhere, you don't have to drive all over them.
This was my first thought too. Making the solar panels into roads (or vice versa) is compounding the problem. Just put the 25,000 mi^2 of solar panels in the middle of the desert and call it even. Adding a layer of glass or some sort of protective surface is going to lessen the efficiency and raise the cost of production and maintenance. I'm all about green energy, but there are better places we could be spending our money and energy.
Ok, thought experiment here: (Score:1, Interesting)
For all the time, energy, and materials needed to make a transparent, wear-resistant glass roadway with solar panels, wouldn't it in fact be easier to stick to concrete/asphalt, and instead build roofs over every highway/interstate in the country? You could put solar panels on top of those, with existing technology, and not have to worry about things like grit causing erosion, oil spills, etc.
Because as phenomenally expensive and complex as turning the entire highway system into a shaded tunnel would be, it would still be less expensive than such a ridiculous melange of technologies. Roads should be durable and provide high grip. Solar panels should be kept clean and run at maximum efficiency at all times. Mushing the two together into some pathetic hybrid is just idiotic.
Quibble (Score:5, Interesting)
How will the oil drippings and the tire residue affect the panel output?
What a dumb idea. (Score:3, Interesting)
So much for the solar panels when a 4 ton 4WD EMT truck rolls along on at 40mph.
RS
What Could Possibly Go Wrong? (Score:3, Interesting)
Re:Oh, get real. (Score:4, Interesting)
For heavily used surfaces it probably wouldn't work.
Most shoulders (in Canada) are paved and very lightly used. Most of the streets in neighbourhoods are also very lightly used (hundreds of slow moving cars per day and not tens of thousands).
I imagine there are locations where this could be used as a surface that is durable enough. The big question mark is production cost (more expensive than current surfacing for a 50 year period) and does it generate enough to make it worth wiring it into the grid.
The test seems very cheap. Surfacing tests of different asphalt mixtures on the order of millions are regularly done.
Re:Oh, get real. (Score:5, Interesting)
One other problem with concrete is that at the "seams" (not to mention the cracks) between panels water can get through to the ground underneath. This can lead to localized soil expansion/contraction which causes stress on the concrete and accelerates the deterioration. If a lot of water gets through the ground can be unstable enough to allow the panels to "rock" then they don't line up evenly any more. I would think these large glass panels could be susceptible to the same problem.
Re:yeah right (Score:3, Interesting)
25,000 square miles is a lot of land to give up, even if it's desert.
A quick back-of-the-envelope calculation shows that 25,000 square miles is about 9.4 million lane-miles, or about 2.4 million miles of 4-lane roadway. This sounds suspiciously close to our total inventory of highway miles of all sorts, everything from Interstates down to country roads, so I suspect that that's where that number came from. I would certainly have a great deal of concern about the issue of wear-and-tear on major highways built using this technology; dealing with that would have to cost more than making normal solar panels, and all they have to do is just sit out there in the sun.
It would seem that there are lots of other places you could put that many solar panels that wouldn't have quite as much of the wear-and-tear issues: roofs of all sorts, for example. Since you don't really need 25,000 square miles of solar panels given current solar panel efficiency and current power needs, that would appear to be a better place to site them first. If it isn't cost-effective there, it won't be cost-effective anywhere.
I think all your missing is (Score:5, Interesting)
able to leap tall buildings and being bullet proof...
I am not overly worried about its resilience, I am more worried about how the surface drains water and traction on when wet. Being an avid motorcyclist I dread new roadway compounds because half the time they forget that two wheelers exist. Rubber directional signs applied to road surfaces are already not friendly, I don't need more.
DoT spending (Score:2, Interesting)
I live in Boise, ID. A very significant portion of the population here visits the non-profit skiing and recreation area about 15 miles out of town. The road to get there is a long windy path that frequently gets icey and literally has steep cliffs along the side. Last year I went up there 5 times and saw 5 accidents on that road (1, 1, 0, 2, and 1 accidents respectively). I even have a picture of an SUV completely flipped over on my iphone as proof. To make things worse, the road is narrow and *very wide* ambulances often SPEED UP IT during the winter to help assist injured skiers. Last year I had an incident where I nearly scraped against an ambulance because it was barreling around a corner, taking up a portion of my lane, which itself was already narrow because ice had formed on the right-hand side and my car wouldn't go over any further. So when federal funding comes in for these road projects, do they spend any money putting up guardrails (yes, steep cliffs and NO GUARDRAILS), widening the road, or employing other tactics to improve safety? No, they blow that money doing a very crappy job indiscriminately resurfacing half the roads in Boise by dumping gravel on it, then the next day dumping oil on it, including ones that were repaved not even a year ago. The result is dings in our windshields and poor looking roads.
So overall, this sounds about on par with DoT spending. These people deserve to get fired, their incompetence with our money is a crime against society.
Comment removed (Score:4, Interesting)
Re:yeah right . . . right-o (Score:3, Interesting)
I think the point is this solar panel roads should be cost neutral when compared to current roads. Current roads are not nearly as durable as one might expect. If they are able to achieve cost parity with current road technology then the electric power generation is a net positive benefit. If they are unable to get the costs down or durability up then this will be a no go.
I personally think the larger problem is surface contour and flexibility. Most roads are not flat. There are constant curves to match the terrain or embankments for safer curves. If we are to use fixed rigid road panels there would have to be many different types of panels increasing the need for precise civil engineering.
The smart money is on solar roofs (Score:5, Interesting)
A much more effective concept is solar roofs. [premierpower.com] Rather than putting panels on top of roofs, the panels are the roof. This has many advantages. Rather than paying for a roof and solar panels, plus the headaches of attaching panels to a roof, you only pay for one surface. Mounting roof panels to rafters is easier than mounting panels to existing roofs. The wiring is on the inside, where it's in a dry space. The panels behave better in high winds, since winds can't get under them. And you can mix solar panels and plain roof panels, using solar panels only on the surfaces pitched to get the most sun.
Roads are a much tougher environment than roofs.
Self Cleaning Glass (Score:2, Interesting)
Comment removed (Score:3, Interesting)
Re:The smart money is on solar roofs (Score:1, Interesting)
Roof over the _roadway_, with the same material. That way you're not covering up any more desert, probably making the roads safer, the solar panels do not have to stand up to such punishment, etc.
I propose naming the first one the Robert A Heinlein Memorial Roadway ( "The Roads Must Roll").
Re:yeah right (Score:4, Interesting)
Solar roadways interview (Score:2, Interesting)
Here's an interesting interview of the inventor:
http://www.blogtalkradio.com/thespiritualenvoy/2009/03/12/The-Spiritual-Envoy-Eva-Ravenwood-and-Scott-Brusaw-of-Solar-Roadways [blogtalkradio.com]
Re:yeah right (Score:3, Interesting)
My bad, I just googled for a random picture of solar-panel things in the desert. 8)
The fact that it hasn't been built just strengthens my point. Event the 'optimal' solar panel sites are uncompetitive with traditional forms of power, or the cheaper forms of green power (especially wind). Throwing away a bunch of efficiency on top of that is just crazy.
Re:Oh, get real. (Score:4, Interesting)
I was going to say, how many accidents would this cause?? If you made the surface with a friction, it would reduce it's ability to absorb light. If you avoided that, you'd have cars that are unstable. I get nervous crossing metal grated bridges. My car sways as it grabs traction on the not quite straight lines in the road. What's going to happen when it becomes impossible to stop, accelerate, or turn (lane change). It's a pending disaster. A little rain, and it's a disaster for safe driving. I will admit, I've done emergency lane changes, because someone did something stupid in front of me. With this plan, emergency lane changes would become impossible, right along with braking.
I'm sure they tested with cars. What happens when you constantly run one over with fully loaded 53' trailers? It's obvious where trucks frequent an area, the ditches created by their weight, even in asphault, would destroy the panels.
But hey, not my idea, and I'm not responsible for the liability involved. We'd be better off using the right of ways (that pesky grassy area on either side of the road) for solar, and they'd be able to track the sun for improved light absorption.
The solar roof conspiracy of silence (Score:5, Interesting)
Forget this. (Score:3, Interesting)
I actually think the perfect application for this technology would be the ground between railroad rails, easy transmission of the power, not a lot of wear and tear and if you suspend them slightly off the ground from the rails, some protection from the elements.
Big, big brass ones (Score:3, Interesting)
I was right there with you.
When I've pictured solar roads, I've pictures roads with a solar "roof" so that it's like you are driving on the bottom of a double-decker bridge. This keeps the road cool (saves fuel expenses on air conditioning) while not impacting actual driving. The only real cost is the scaffolding for the panels, which is usually dwarfed by the cost of the land the solar panels sit on. Since the road area is effectively free (or dang cheap) this is a win-win situation. Drivers don't have to roast in hot (Western US) sun, and the grid gets lots of juice at the time of day they are most likely to need it.
But the road itself!?!?! There are so many issues with this I don't know where to begin:
1) Dirt/grit/oil/grease. Ever walk barefoot on a road? Your feet are black within MINUTES. Ever walk barefoot on a freshly paved road? Not so much. Roads are nasty, dirty places with noxious dust from brakes, oil sling, grease droppings, and an occasional tire screetch smear. I can't imagine more than 50% of the light getting to the road in the first place, what with all the silt, dirt, sand, and the like. You want this to be see through?
2) Abrasion. So you have a road, covered with a fine layer of silt. Sandy, dusty, gritty stuff. And then, for good measure, you grind it all in with a 75,000 pound semi every 30 seconds or so. You still want this to be see through?
3) Expansion/Contraction. In the summer, the road surface hits 140 degrees. In the winter, it hits 10 below zero. With traffic, and snow plows - another big knife blad, with a 35,000 pound tractor behind it. Uh, yeah.
4) Accidents. So a semi crushes a small import at high speed. Pieces of metal go flying in all directions, and the chassis of the import becomes a 1,500 pound, 6 foot long knife blade being ground into the road at 65 miles an hour by 75,000 pounds of angry 18-wheel semi. Normal asphalt would have a nice groove in it 3/4 of an inch deep that would cause a "tick" noise as you drive over it. But what's that going to do to a PV road?
I'm not one who normally encourages negative responses to engineering challenges. But this strikes me as fundamentally... stupid. It's like using a hummer to drive fuel tanks of alcohol across the US and calling it "green shipping". Good luck getting anything north of 5% efficiency over 5 years.
Build a scaffold. Put the panels up above. And enjoy 50 years of quality cheap electricity, while making it cooler for the drivers and saving fuel to boot.
Re:Hacker's dream (Score:3, Interesting)
That might pull in even more money than the electricity generation. Sell moving ads in the roadway. (ARRGH!!)
Re:Oh, get real. (Score:1, Interesting)
So the roads are giving off heat...
1/ Is this enough heat to melt the rubber on vehicle tires?
2/ Can it burn the skin?
3/ What about chewing gum and other pieces of crap that will get onto the roads?
Will the glass get dirty? (yes) How will this affect efficiency? How easy will it be to clean?
Will the paint needed for the road markings stick to the glass? If not, will coloured LEDs work? And if so, how much power will they use? Are they always guaranteed to work? How visible are they? Will they distract drivers?
I'm not saying that this can be a good thing, but at least test it before committing to using it on a large-scale section of road. Lay out a reasonable stretch of road and have extensive usage in different conditions in a safe manner.
Re:Oh, get real. (Score:3, Interesting)
People should really read the FAQ [solarroadways.com] and the numbers [solarroadways.com].
To sum up: it's significantly more expensive, but since glass doesn't wear like asphalt does (it either works or breaks -- and it doesn't generally break from compressive stress, only torsional stress and impact), it should last longer and need less maintenance. And since you also get power out of it, displace plow crews, etc, they make the argument that it'll be a better investment if they can make the panels for $10k or less each.
Given that the one-off prototype is to cost $100k, and they have the potential for a *huge* amount of mass production, I don't think it's all that unrealistic. I'd still like to see how they handle in the real world, of course, but hey, that's why you give funding to build prototypes. ;)
Oh... yes! The numbers! I love the wishful naive thinking on that page, it's just brilliant.
For example, lets examine one of the pieces of insanity on his site. He mentions embedding supercapacitors into the road surface to store energy (I assume overnight). If you don't know what those things are, they would be the filthy expensive, highly experimental, rarely used in commercial products devices with lower than battery storage capacity. I'm sure they'll improve, but I can come up with fancy plans too if I can have parts made of unobtanium.
I particularly like the plan to use the ultracaps to store sufficient power to melt ice off the roads. The inventor clearly doesn't remember his 1st year Physics, where we learnt that the the enthalpy of fusion of water is surprisingly high compared to most other chemicals.
Ok, lets get practical: I'm basing this off the technical specs [maxwell.com] (PDF) for one of the beefier ultracapacitors made by one of the top companies in the biz - Maxwell Technologies. (note: I'm sure better devices are available from somewhere else, will be soon, etc.. bear with me)
It states that a device that is about 17.6cm high and has an area of 18.9cm x 51.5cm has a total capacity of 55Wh (~200kJ). That's a big capacitor.
So if you made a road surface with it, every 973.35 cm^2 area would have 200kJ of stored power for it. That's about 200J per cm^2.
Since the enthalpy of fusion of water 333 J/g, then 200J of energy will melt 0.6g of water. A layer of water (or ice) 0.6g/cm^2 is 6mm deep.
To summarize, this guy's fancy 'invention', if 100% efficient could melt 6mm of ice (or something like 5cm of snow), assuming that the weak winter sunlight was sufficient to fully charge the capacitors during the previous day. That's assuming the entire road surface has a layer of supercapacitors in it 17.6cm thick (that's 7 inches for you yanks).
Even if you gave the benefit of doubt and assumed a 10x improvement in supercapacitor technology, you still have to factor in that he plans to use the solar power capacity for other things too, like lighting up the LED arrays built-in to the road, and to power nearby homes. Not to mention that no matter how much capacity you have, there's not enough sunlight to charge it.
Note that the cost estimates conveniently left out the cost of the ultracaps. On one of the pages, he mentions a target price of USD48 per square foot. The Maxwell ultracap is about 1 square foot, so we're looking at $48 split between a square foot of: Solar cells, the glass coating, an ultrapacitor 7 inches thick, high intensity LEDs, heating coils, power management electronics, the road substrate, and more.
Who was the moron who gave him $100K? Can I have my free money now too? I can come up with all sorts of wild plans also that make zero fiscal sense!
Re:yeah right (Score:2, Interesting)
I agree with your contention that the best place to locate solar panels is in the desert.
But, I think you've missed the boat with the heat analogy entirely. I can imagine that a panel on top of a car in a desert race would heat up, but that's not what this project is building. The panels will be located on an enormous heat sink that's always cool, no matter what the air temperature is. Have you ever been in a hot desert? Just dig a few inches under the top layer of sand, and it cools down dramatically. This is why heat pumps work (to cool building down).
The contact with car tires will also be multiple inches of glass away from the panels themselves. They're not going to be heating the panels up.
And of course a traditional road gets hot. That's the whole point behind the promise of this technology! That's the enormous amount of solar energy. On an asphalt road surface, that all gets converted to heat. Solar panels are dark, too, but they're using the photons to generate electricity, instead of solely heating the road surface. Such a road would also lose some incident energy to reflection, which asphalt does hardly any of.
I'm not saying heat is a non-issue, but I think your example is a poor one, that overstates the problem.
Re:Oh, get real. (Score:3, Interesting)
Yet another reason why it would be better to build the cells as a roof above the road as I mentioned in a post further down this thread. Then you can give the cells a slight tilt and use electric heating to only melt a tiny layer of snow beneath them, causing the rest of it to slide off.
Re:Unsafe? (Score:3, Interesting)
Glass as in your window or tabletop is slippery when wet only because it's smooth. It's not hard to imagine a texture grabby enough for tires: gritty like sandpaper, or a micro version of the "diamond" plate used in industrial catwalks.
Further, since it would be on the bottom of a mold at the factory, the pattern could be made quite deep so it'd take longer for it to wear down (plus glass is harder than asphalt or even concrete). Add the right grooves for drainage, and you're set. The only remaining problem is resiliency so it won't shatter when a semi truck eventually loses control and rolls on it.
Re:Not economically viable (Score:2, Interesting)
I met Scott Brusaw, founder of Solar Roadways (Score:2, Interesting)
My god, it's full of tires... (Score:3, Interesting)
In addition to all the engineering nightmare problems people have already mentioned...
You replace your car tires every few years because the rubber has worn off, right? Well, where did the rubber go? You smeared it all over the highway. A lot of it turns into fine dust, but some of it gets literally welded onto the road surface, even in normal driving when you're not skidding or burning rubber.
All that black rubber is covering the road. The dust filters into the cracks and crevices that allow the road to grip tires in wet weather. The smeared tire goo sticks to everything. If you've ever seen a concrete highway roadbed after a year or two of heavy use, it's covered in black grime.
One of the biggest problems people have been having with rooftop solar panels in long-term use is keeping them clean. They get dusty, birds poop on them, etc., lowering the efficiency dramatically. Highways make rooftops look as clean as a hospital in comparison.
That said, this looks like a good use of $100K. That's chump change for government research. Have these guys make a roadway solar panel, stick it in a real roadway for a year or two, and see what happens.
I'm willing to pay $100K of government money to put a bad idea to bed.
It doesn't hurt to try. (Score:3, Interesting)
Lets look at some of the problems:
Durability
Can glass stand up to punishment? We're not talking about house glass here. Anyone who has been to a hockey game knows how much abuse glass can withstand. Truth be told asphalt requires a ton of maintenance or it quickly deteriorates. Snowplows? Of course they will do some damage, but the question is: how much? They're already very hard on asphalt roads. Dirty? Well, we may find that street sweeper technology is effective. Having said that, if we do decide to implement this idea, I suspect that we would end up with a hybrid system. It would be foolhardy to suggest that one solution should fit all. I suspect that concrete or something will take the majority of the punishing loads with these panels along the shoulders or in parking lots or sidewalks. This idea may be more suited in certain climates and not others. At least to start.
Cost
Yes, this is more expensive than asphalt. But what are you getting for your money? If the inventor is to be believed, this surface would last 3X as long and would also incorporate the energy infrastructure of the nation. When people throw out trillion dollar numbers in regards to redoing the entire country, that's a bit of a scare tactic. Much of that money will have to be spent anyway repairing what we already have. If you eliminate some of the ideas such as the ultracapacitors and LED lighting, the costs could be brought down further.
Future Possibilities To me, the most exciting aspect of the solar road is what sort of possibilities it opens up.
1. The electric car is coming. Imagine cars that charge while they drive, or at least when you park at a mall!
2. By incorporating the energy infrastructure into the roads, you eliminate the need for overhead power lines and the associated battles that accompany the building of new lines. Power lines are crucial for other renewables such as wind.
3. If done right, you start to build the mythical 'smart grid' Certainly there are an abundance of problems that may occur, but, I haven't read anything on this site that is not solvable. Everything required to make this project work is already a proven technology. The only question-mark is if they can be combined and if governments and business will embrace this idea.
Use the rest of the right of way? (Score:2, Interesting)
Right now most of the right of way isn't covered with road, it's covered with grass, bush and weeds. This may make more sense for such a venture.
* People don't drive (often) in the ditches and median.
* By putting them on angles, we could eliminiate the snow sticking issue.
* In the latter case, the land underneath would go to shade tolerant species and the land would still be available for soaking up rainfall.
Perhaps a better alternative would be to enclose the roads in snow shed like structures (roofs on posts) This keeps the roads dry most of the time, and allows a cheaper less sturdy alternative photocell.
You still end up with your power being distributed in long thin lines.
According to one book I have on landscape design alternatives, half the impermeable surface in urban areas is roof. Seems to me that putting cells on roofs (and in Canada on south facing walls) makes a lot more sense:
* No one drives on roofs, other than parking lot roofs.
* The average transmission distance is way down: Your customer is often quite near.
Or How about putting them up in nice neat rows in a desert? Hmm.
* Doesn't need paving grade cells.
* Can tilt to maximize light absorbtion.
* The power is in much more concentrated locations, making it easier to tie in to the grid.
* Not nearly as much driving to fix things.
* Less worry about casual vandalism.
What a great idea. If I weren't so selfless I'd run out and patent this today before someone else thinks about it.