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Power Transportation Technology

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."
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Solar Roadways Get DoT Funding

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  • by virmaior ( 1186271 ) on Friday August 28, 2009 @10:07PM (#29238841)
    at least one of the claims here seems a little off: []

    in particular, this sentence: "This means that if each individual panel can be made for no more than $6912.00, then the Solar Roadwayâ can be built for the same cost as current asphalt roads." It seems to assume that an outlay of 3x the money for a road that lasts 3x as long is the same cost as 1x & 1x respectively. While this is true for someone with infinite readily available money, the reality is that most places don't have enough money for that.

    also "The Solar Roadwayâ will, therefore, eliminate half of the greenhouse gases currently being produced. " seems to be a dramatic overstatement.
  • Re:Oh, get real. (Score:5, Informative)

    by Shikaku ( 1129753 ) on Friday August 28, 2009 @10:15PM (#29238881)

    Concrete is solid like a rock. The reason concrete cracks in the weather is because it expands and contracts because of the temperature and water content. If the solar panels were a lot more pliable, just as strong, waterproof, and had something like the self healing plastic abilities, I think it can work just fine.

  • by Anonymous Coward on Friday August 28, 2009 @10:18PM (#29238893)

    They claim the Solar Roadways are self heating and shouldn't need to be plowed since the snow wont' accumulate.

  • by erroneus ( 253617 ) on Friday August 28, 2009 @10:30PM (#29238963) Homepage

    There was a building designed with flooring that uses the energy of people walking on it to help power the place.

    I think that solar power might be ridiculously expensive, but if they captured the hear from the road's surface and extracted the energy from that in some way, it might be quite effective and a lot less expensive. I can't speak for roads in other parts of the country, but here in Texas, walking bare foot on any paved way or even on sandy soil will result in burns in the summer.

  • Re:Oh, get real. (Score:3, Informative)

    by Socguy ( 933973 ) on Friday August 28, 2009 @10:40PM (#29239033)
    Perhaps, but according to the article, the panels will heat themselves thereby eliminating the need for snowplows.
  • Re:yeah right (Score:3, Informative)

    by madcat2c ( 1292296 ) on Friday August 28, 2009 @10:44PM (#29239067)
    Your assuming mile wide lanes. Lets assume 2 lane roads. Normal 12' wide lanes means 48' of width.
    5280'long X 48' wide = 253,440sq feet per mile
    253,440sqfeet per mile X $43 = $10,897,920 per mile
    $10,897,920 per mile X 25,000 miles =

    So $273 billion or so for nationwide energy independence would be pretty cheap if you ask me.
    I cant keep my kids eyeglasses from getting scratched up every six months, so im not sure how they will keep the clear covering scratch free...if they cant then that efficiency goes way down I bet.
  • Re:Oh, get real. (Score:3, Informative)

    by timeOday ( 582209 ) on Friday August 28, 2009 @10:48PM (#29239085)
    Oh, just shut up. You you have no good reason to think this won't work, this is just your biased gut reaction to anything associated with efficiency or alternative energy savings, and nothing more. Lead, follow, or get out of the way.

    The two tracks that take 90% of the wear in each lane cover relatively little of the road, and this doesn't have to be cost competitive with non-energy producing roads because energy is valuable! Roads cover vast swaths of space, which is mostly wasted. So I really hope this works out.

  • by GodfatherofSoul ( 174979 ) on Friday August 28, 2009 @10:48PM (#29239089)
    I've noticed that the quality of this website has slowly decreased to the point it's not my first look anymore. After reading all of the armchair scientists instantly shooting down an experiment with I'm sure they have an inversely proportional knowledge of the subject and hand, I've think I've finally figured out. The AOLers are ruling the roost.
  • Re:yeah right (Score:5, Informative)

    by bertok ( 226922 ) on Friday August 28, 2009 @11:13PM (#29239255)

    ...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.

    Back at uni, I did a mini-course on the the Solar Car challenge [], because my University [] made some of the solar panels for the top cars, and we also had a car that entered and did fairly well (for a low budget). One of the things we learned was that solar cells lose efficiency very quickly from a variety of things. The two that most researchers ignored in the lab but mattered in the field was heat and dirt. The cars in the race are washed with cold water thoroughly at every opportunity because colder, cleaner cells are substantially more efficient. Think CPU overclocking - lower temperatures improves things a lot.

    Now lets compare this situation to a typical road which is:
    a) Blistering hot most days.
    b) Really, truly, thoroughly dirty.

    Sounds like the perfect place to put an expensive solar cell panel!

    Another thing we learned is that a single "test" panel in a lab operates very differently to a bunch of real panels in the field. What a lot of naive researchers miss is that the amount of sunlight over the entire collecting surface in the real-world is not constant. For a one-square-foot panel, it is, but for any significant surface (the size of a car, road, whatever), it won't be. The surface will be curved or partially shadowed. This matters a lot because if you just connect a bunch of cells together, they perform roughly the same as the worst of the lot. If there's a few cells under a shadow, that's drags down the efficiency of the panels receiving sunlight. To efficiently extract energy from a bunch of panels receiving differing amounts of light takes a bunch of expensive power management electronics that can combine the different cell outputs in the right way.

    In practice, cells are so expensive that the best place to put them is on huge, flat, orientable panels out in the desert where there's no clouds, no rainfall to cake dirt onto the panels, and they can be oriented to face the sun at all time, like this array in southern California [].

  • Re:Oh, get real. (Score:4, Informative)

    by RobVB ( 1566105 ) on Friday August 28, 2009 @11:13PM (#29239257)

    This should be applied first in the southern states, because a solar panel in a southern state will yield more energy than a solar panel in a northern state (like Minnesota), as opposed to fossil fuels, which yield the same amount of energy regardless of where you burn them.

    People do seem to be focusing too much on the problems and not enough on the benefits, which is a healthy point of view when you're talking about scientific developments, but most problems I see people pointing out here are easily solved or circumvented. Freeze/thaw cycles are one, the solution being: build them in the warmer states.

    Timothy Brownawell wrote about another problem:

    Oh, lovely. So instead of just snow, you'll be driving on a layer of slush/ice on top of a little water. That's about as bad as it can get, except for maybe a flash flood.

    Again, this problem is relatively easily solved by making sure the roads are properly drained. Slightly slope the roads to the side so the rain or molten snow drains off into a sewer, and you don't have the slush anymore. This snow problem is also severely reduced by building these roads in California and Florida instead of Alaska and New Hampshire.

    copponex wrote:

    Yes, if the people who designed this system are absolute morons, they may have forgotten that trucks exist and are heavy.

    Trucks do exist and are heavy, and do wear down roads and highways quickly. The thing is, a lot of roads aren't heavily used highways, they're calm streets in suburbs.

    As rtaylor wrote:

    Most of the streets in neighbourhoods are also very lightly used (hundreds of slow moving cars per day and not tens of thousands).

    These quiet streets get just as much sunlight per square meter (substitute by your favorite unit of area) as the big highway a few miles further. No need to change the entire transportation network into a power plant at once, you can keep your heavy trucks on asphalt highways, and keep the solar panels in the suburbs where people drive slowly, and heavy trucks are barely ever seen at all.

  • Re:Oh, get real. (Score:5, Informative)

    by Rei ( 128717 ) on Friday August 28, 2009 @11:41PM (#29239429) Homepage

    Can we stop acting like the cars are driving directly on top of the solar cells? They're not. They're driving on glass, treated for greater impact resistance and a textured surface. The question should be, how well does treated glass withstand winter damage?

  • Re:Oh, get real. (Score:5, Informative)

    by Rei ( 128717 ) on Saturday August 29, 2009 @12:22AM (#29239701) Homepage

    People should really read the FAQ [] and the numbers [].

    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. ;)

  • Re:Oh, get real. (Score:5, Informative)

    by Rei ( 128717 ) on Saturday August 29, 2009 @12:33AM (#29239775) Homepage

    Is reading the FAQ [] too much to ask?

    Try this: Go to Google Maps [] and start looking at roads. Random roads. Select without bias. Tell me how much of the road surface is covered on average. Then go deliberately seek out traffic, and again, tell me how much of the road surface is covered.

    Even in "bumper to bumper" stop-and-go traffic, about half the roadway is exposed. On average, a quick glance at the US's road system suggests that perhaps 98% of it is exposed at any point in time during the day, and perhaps 90% in cities.

  • by cbiltcliffe ( 186293 ) on Saturday August 29, 2009 @12:41AM (#29239823) Homepage Journal

    You do realize you're talking about a country that's over 3000 miles wide on average, right?
    And roughly 2000 miles north to south?
    And that's not including Alaska....

    Add in all the little screwy subdivision roads, right up to major 4 lane highways.....I'm surprised it's only 25,000 square miles, to be honest.

    According to Wikipedia, the US is roughly 3.8 million square miles in area.
    25,000 square miles of roads means that roads cover only 0.66% of the surface area of the US.

    That's not exactly a lot.

  • I don't think the idea is to tear up perfectly good roads to replace them with these solar panel. New roads are built all the time, use this instead of the traditional asphalt for the surface. Roads wear out and need to be resurfaced, when it comes time for that the solar panels can replace the asphalt, concrete, gravel, or whatever.

  • Re:Oh, get real. (Score:2, Informative)

    by alaffin ( 585965 ) on Saturday August 29, 2009 @01:50AM (#29240097) Journal

    I'm going to go out on a limb and say that none of this is going to be laid down anywhere that sees snow more than once a century, despite what is written above. Although I can't be certain, I can't imagine the heaving and shifting a road undergoes during that sweet spot where things (water, specifically) freeze overnight and thaw during the day would be healthy for those solar cells. Here in Canada we can barely get regular highways to stay in good condition over more than a couple winters. Those fragile solar cells would be toast.

  • Re:A dumb argument (Score:3, Informative)

    by jsebrech ( 525647 ) on Saturday August 29, 2009 @05:53AM (#29241065)

    You might want to give a practical example of an unregulated market that tends towards optimal efficiency.

    The problem is this: the free market makes prices drop to marginal cost levels, so market agents have two incentives: (1) merge and acquire to increase scale and drop costs, so as to achieve higher profits, and (2) find ways to reduce market freedom so prices no longer have to remain at marginal cost levels. These two incentives combine to reduce market efficiency. Let any market run free, and it will rapidly tend towards oligopoly. Once the number of players becomes small enough, they start to cooperate to reduce market freedom and raise prices.

  • by iamhassi ( 659463 ) on Saturday August 29, 2009 @02:07PM (#29244847) Journal
    " they assume that the cost of making roads is 100% laying down asphalt. "

    not really. RTFA: []
    "The average cost of asphalt roads in 2006 was roughly $16 per square foot. The cost does not include maintenance (pot hole repair, repainting lines, etc.) or snow/ice removal. The average lane width is 12 feet, so a 4 lane highway would be 12' (width per lane) x 4 (lanes) x 5280' (one mile) = 253440 square feet. Multiply this by $16 per square foot and your one-mile stretch of asphalt highway will cost $4,055,040.00 and will last an average of seven years.

    We plan to design the Solar Roadwaysâto last at least 21 years (three times that of asphalt roads), at which time the panels would need to be refurbished. Adding no additional cost to the current asphalt system, this will allow us to invest about $48 ($16 x 3) per square foot. This means that if each individual panel can be made for no more than $6912.00, then the Solar Roadwayâ can be built for the same cost as current asphalt roads. However, asphalt roads don't give you anything back."

    Why not make solar roofs above the roadways? Now you have nothing driving on them and they won't get as dirty as a road would.

    Of course then you still have all the costs of the roads + cost of raised solar panels.

    oh... they answered my question:
    "Wouldn't it make more sense to just build canopies over the roads to hold the solar panels? Or just place solar panels on the north side of the roads, facing the sun? That way, we wouldn't have to be able to drive on them?

    No. It would be incredibly expensive as you would still have to pay for our current asphalt roads. We plan to use the money already budgeted for roads for the replacement Solar Roadways. If we still had to build current roads plus the canopies or side panels, the cost would likely be so high that taxes would have to be raised to cover it. You would also lose most of the features of the Solar Roadways, such as being lit by LED's for safer night driving. The side panel idea would do nothing to keep the roads free of snow and ice, so northern cities would still have the removal expense and the accidents caused by the unsafe road conditions. Many of the other features would be lost too, such as saving the lives of millions of animals, a self-healing, decentralized power grid, all aspects of an intelligent road: reporting in with potential problems, reducing crime and terrorism, etc.

    Ah they used terrorism! The instant govt money buzzword since 2001! That'll get them money.

    Exactly how is the electricity going to work? Am I getting free electricity? I mean if my taxes paid for it, I should get it free, right? Or huge discount?

BLISS is ignorance.