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View Diary: Solar Roadways: A proposition (110 comments)

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  •  Honestly, it makes no sense to me (10+ / 0-)

    to make roadways solar - which has a host of engineering problems - before you get solar arrays on a significant percentage of sun-exposed roofs in the US.

    The next place I would go is parking lots. My instinct says that putting panels OVER parking lots is going to be more affordable and cost effective than making parking lots themselves solar arrays.

    Driving over things breaks them. The asphalt roadway next to my house is a prime example... and it's 20 years overdue for repaving with conventional materials, something they're having trouble funding.

    Fry, don't be a hero! It's not covered by our health plan!

    by elfling on Mon Jun 09, 2014 at 12:12:06 PM PDT

    •  Yes (4+ / 0-)
      Recommended by:
      rduran, HoundDog, SCFrog, koseighty

      I'd like to see hexagonal glass tiles survive Vermont frost heaves.

      Not a chance in hell.

      •  Do traditional roadways? /nt (0+ / 0-)
        •  No (5+ / 0-)

          That's kind of my point.

          Anything in the form of tiles I would suspect would have some issues with freezing/expansion far worse than traditional roadways.

          Not to mention the ridiculous amount of underground components for this.

          Small scale in a mild climate in a low load, low grime environment...sure, it's a great application.

          Nationwide, I don't think it's gonna happen.

          •  You'd be wrong, actually (1+ / 0-)
            Recommended by:

            Roadways have cracks and potholes primarily because they're one long stretch of asphalt melted together. Ever wonder why sidewalks were laid out in square blocks? It's to help prevent cracks in the pavement. The flexibility inherent to tiles, blocks, hexagons, etc is a benefit, not a curse.

            •  Rubbish (1+ / 0-)
              Recommended by:

              So tell me, why are roads not paved with tiles if this flexibility is so wonderful?

              I am beginning to think the people behind this are scammers - especially the bit in their video that shows them shoveling colored recycled glass into a wheelbarrow, as if they are going to make tempered glass from it!

              •  they're hardly scammers. watch some of the (0+ / 0-)

                actual project videos (not just the marketing stuff)

              •  Adds cost (0+ / 0-)

                And believe what you will, but it passes the smell test to this engineer.

                •  You forgot (1+ / 0-)
                  Recommended by:

                  to tell my why tiles aren't used for roads due to their superior "flexibility".

                  Whenever your engineering duties give you a break, perhaps you can answer that?

                  •  what's the animosity all about? (1+ / 0-)
                    Recommended by:
                    Le Champignon

                    just curious.  It's an engineering project, for crying out loud.  If you don't think it'll work, fine.  Others think it will.  In the end we'll find out.  Even if it doesn't work on any scale, teh proejct still has great potential to spur applied science/technology.  

                    •  Agreed (0+ / 0-)

                      I'm happy to answer questions from my perspective, but I'm not going to do so for someone being a smartass like choco. There's a lot of animosity towards this project, and I'm curious as to why.

                      •  you see this with a lot of large-scale projects... (0+ / 0-)

                        i think in some cases people simply don't believe in the projects and they see them as a waste of money (see the occasional vocal opposition to some NASA projects, things like CERN,etc).  

                        some people are threatened by imagination, to be honest.

                        I'm cautiously optimistic about these people.  Maybe not that it will completely change the world (it might) but that it might really move some things forward at a local/urban level.  We'll see...

                    •  What animosity? (1+ / 0-)
                      Recommended by:

                      You still have yet to answer the question. Which is kind of symbolic of this entire proposal - there is very little "there" there.

                      Why are tiles not used for roadways if they are better?
                      Simple question.

                      I am all for green energy. This doesn't mean blindly supporting every half-baked idea to come down the pike, which is how I would characterize this project.

                      As many others have pointed out, there are giant gaping holes in the claims made by these folks. The snowmelt claims being the most obvious fail.

                      Let me know when they run the first large truck crash test on their glass roadway, won't you?

                      •  so because Choco8 isn't exactly sure how the (0+ / 0-)

                        snowmelt is going to work, the idea is a complete crock of shit and should be abandoned.

                        You realize they got a major grant frmo the DoT, have support from companies like google (hell, even their own senator)

                        another link

                        Have you researched it?  Diarist has.  And I've read a fair bit.  Sounds promising.  Earth shattering?  who knows...but defintiely worth the initial few mil investiment.

                        Again, where's your animosity coming from?

                        and your qeustion was answered--they're not using tiles now b/c of cost.  But this system pretty much demands it.

                        •  Not quite (1+ / 0-)
                          Recommended by:

                          No, it's because the people pushing this concept have not adequately explained just how this system is miraculously going to work in cold snowy Northern climates.

                          Of course, many of these types of issues have already been thought through in terms of the design criteria for heated roadways. A classic document states that "[s]now and ice melting systems must provide sufficient heat to melt snow as well as to offset surface heat loss by evaporation, convection and radiation and heat loss from the slab into the ground." One presumes the solar road advocates have all these heat loss numbers worked through? If so, where are they? Such calculations are one of the first steps in assessing this technology, and are not looked into only after large amounts of taxpayer dollars are spent. They are critically examined beforehand.
                          And yes, I have read quite a bit about this. The more I read, the more ridiculous and unworkable it a nationwide project.

                          As I have stated earlier, for small scale, low load situations in a mellow southern climate, this might be good for some applications, but it is FAR from being proven a workable concept on a nationwide scale, much less proven to be the best use of funding given the alternatives like rooftop solar.

                  •  plus your question was answered: (0+ / 0-)

                    "adds cost".  That would be the case here, too--although in this case the system pretty much has to be modular--by definition.

      •  tempered glass (0+ / 0-)

        is stronger than steel.

        Be the change that you want to see in the world

        by New Minas on Mon Jun 09, 2014 at 12:36:31 PM PDT

        [ Parent ]

        •  The joints (1+ / 0-)
          Recommended by:

          and expansion would be a real issue in northern climates, if not a deal-breaker.

          And what happens if a single tile fails? Does all the water gush into the underground section, laden with electronics?

          Big Trucks. They break shit. They don't care what's it's made of.

    •  There are three main arguments (2+ / 0-)
      Recommended by:
      LakeSuperior, koseighty

      1. A specious argument about how transmitting power through road surfaces is better than over suspended wires.  

      2. Unexplained snow removal.

      3. Unquantified assertions that solar roadways will substantially improve EV range (versus, well, charging stations).

      •  thee "main" arguments (0+ / 0-)

        main as in primary or main as in, these are the ones that I have answers for so that I can criticize it.

        how about the specious argument that below ground cables are better than above ground cables for the transfer of electrical energy, from a city planning perspective.

        how about the fact that snow melts and water runs off of roads. . .

        solar roadways, (or any roadway with the proper equipment) can be adapted to charge EVs  see my link above, Volvo is doing it already in Europe.

        however, these are only small benefits.

        others are

        1. increased durability of roadways,
        2. increased signal and traction safety of roadways
        3.  energy generation as a byproduct of the used space
        4.  instant accident sensor ability with remote emergency services call
        5.  the potential for all kinds of new technological developments that are unforeseen as in, what happens when the self-driving google car is mated with an EV charging solar-powered road grid that has communication and internet capability?

        This is so new and so big, you and I cannot possibly fathom all of the potential technological benefits that I will bring (if we could we could be rich!!!!)

        Be the change that you want to see in the world

        by New Minas on Mon Jun 09, 2014 at 12:43:03 PM PDT

        [ Parent ]

        •  Still unexplained (3+ / 0-)
          Recommended by:
          LakeSuperior, koseighty, Choco8

          Simply reiterating that snow melts doesn't show us the math behind snow melting.  

          Simply pointing out Volvo can charge a parked, unoperating vehicle in 2 1/2 hours doesn't make the case for SRs (though it makes the case for solar powered parking, which does not require integrating the PV with the charging system).  

          I also point out that none of this is detailed in the SR system documentation whatsoever.  Congrats, Minas.  You've done more work "explaining" how SR works than SR itself.

          As for your 1-5, that's nice.  But show me the money.  I'd also point out that:

          1. Don't need solar panels to improve roadway durability.
          2. Or signal safety or surface traction
          3. Don't need to put PVs in roads to increase energy generation as a byproduct of used space.
          4. Don't need to build in accident detection into the road system, or if you really want something vehicle independent, no need to build them into the roads themselves.
          5. The same thing that happens when a self-driving google car is mated to a wireless network.

          Solar is big, if not new.  Solar Roadways, however, is looking more and more like and oversold science project every day.

          •  reread (0+ / 0-)

            what I posted,

            the vehicles are being charged while driving.

            the earth currently supplies about .075 watts per square meter 24/7 already (due to subsurface heat)

            so all we need to do is augment this when it is cold at night and there is precipitation.

            This is easily doable.  all we need to do is keep the substrate above freezing and the residual heat will do the rest until the sun comes back up.

            so figure the amount of snow/ice you want to melt per square meter (figure 1.5 inches of snow accumulation)

            assume at 30 degrees F

            then calculate the amount of mass thermal conversion to 32 degrees of water then calculate the phase change and give it a good estimate of the total amount of time you need (say 6 hours)

            this is only while defrost operations are needed.

            don't forget to look at the amount of water/slush that is pushed off of the road by moving vehicles.

            Be the change that you want to see in the world

            by New Minas on Mon Jun 09, 2014 at 01:24:55 PM PDT

            [ Parent ]

    •  Many things wrong with this idea (3+ / 0-)
      Recommended by:
      PeterHug, koseighty, Choco8

      Here are some engineering criticisms:

      Long story short, apart from fragility and maintenance concerns, putting panels in roads seems designed to maximize the cost of solar power.  Why not put them on roofs?  It's not as if America lacks buildings -- mall roof space alone is at least 40 square miles.

    •  Everything has engineering problems (0+ / 0-)

      To address some of your points, there's absolutely no reason why we cannot had solar roofs and solar roadways; putting panels over parking lots removes several key advantages of the Solar Roadways technology; and it's a funny fact, but asphalt is actually significantly easier to break than these panels.

      •  When asphalt breaks (5+ / 0-)

        the road is still a road.  A slightly less nice road, but it remains a road for quite some time before someone comes along to repair it.

        When tempered glass breaks, not so much.

        Vehicles are incredibly destructive to the surface under them. And remember that it's not just tires that will be over the surface, but say rocks and debris that are then run over by trucks. They leave tire residue on the surface.

        If the surface is perfectly flat, the vibration from vehicles is less. Near my house there is a mountain pass that has an incredibly wavy surface to it, with all kinds of discontinuities. People will just accept that Caltrans must not have graded it very flat. But in fact, those waves and dips occurred despite substantial soil engineering and a complete regrading project only a few years prior. They actually started getting dips in the first lanes they finished before the last lanes were done. Welcome to the wet and pudding-like soil of the north coast.

        But this adds stress to the roadway, breaking it outright or setting up vibrations in the vehicles that then take their toll on the roadway. The vibrational force from a large truck should not be underestimated. It's this dynamic load that makes trucks destructive, not their raw mass pressing down.

        And solar parking lots, where the paving surface is the collector, rather than the roof, have kind of a fundamental problem. Which is that people park their opaque cars on them during the daytime. And then thoughtlessly leave them there for hours.

        Fry, don't be a hero! It's not covered by our health plan!

        by elfling on Mon Jun 09, 2014 at 01:51:11 PM PDT

        [ Parent ]

        •  couple thoughts about parking lots (0+ / 0-)

          i'm not remotely an engineer.  I guess the extent of usable space on a parking lot (not covered or heavily obstructed by cars) depends on the lot.  I assume it could be anywehre from, say, 30-70%.  But I wonder if parking lots could be built on a slight incline to maximize efficiency (with simple curb/barriers like we have in many parking lots anyway).

          Also there could be a perimeter of properly-angled panels around the lot itself.

          •  Nah, can't angle them (1+ / 0-)
            Recommended by:
            Namazga III

            Not to any appreciable degree, anyway. Maybe a few degrees to make up for one's latitudinal angle (i.e. the one that helps reduce the effects of higher latitudes on the received power), but the longitudinal angle (i.e. the one that tracks the sun over the course of a day) can't be done.

          •  The needs of the people parking (2+ / 0-)
            Recommended by:
            Namazga III, koseighty

            should take precedence over any auxiliary power generation.

            Some slope is desirable to move water off the parking lot surface. But even a relatively small slope, in solar terms, creates problems like shopping carts that roll away and make it inconvenient to use. And again, terrain remains a factor.

            A comfortable parking lot will make a difference in whether people choose to patronize a particular location. Shade is a huge part of that here in the west. In a typical parking lot, it's usually the shady spots that are taken first, not the ones closest to the entrance.

            Cal Expo in Sacramento has solar panels covering part of its parking. Those spaces, even though they are narrower and further than some other choices, always are filled first.

            Fry, don't be a hero! It's not covered by our health plan!

            by elfling on Tue Jun 10, 2014 at 08:10:50 AM PDT

            [ Parent ]

            •  Water Not a Problem (2+ / 0-)
              Recommended by:
              Namazga III, elfling
              Some slope is desirable to move water off the parking lot surface
              But don't forget:  According to the video, water treatment plants will be built into the substructure of this miracle pavement, to filter, treat and distribute fresh, clean, heathy water to nearby neighborhoods.

              I can't wait for version 4 which will undoubtedly include a snow cone maker -- shipping snow from the the snow burdened north, through the under pavement network to sunny Florida -- delivering the snow cleaned, purified, and perfectly chilled to eager kids of all ages.  Just add the topping of your choice.


    •  I mentioned above (2+ / 0-)
      Recommended by:
      Choco8, Odysseus

      that there are schools around here that have solar arrays in their parking lots, as well as a solar installation which acts as protected parking for the buses at the bus yard where Mr. Scribe used to work. It's a win-win; you have the solar array, and people can park their car under shelter when it's damp or to protect from bird droppings.

      There's only one rule that I know of, babies -- goddammit, you've got to be kind. -- Kurt Vonnegut

      by Cali Scribe on Mon Jun 09, 2014 at 12:39:05 PM PDT

      [ Parent ]

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