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Not sure why you are being downvoted, but I thing your comment makes a lot of sense, and I'd like to know why some think otherwise.

by guiomie 11y ago

_Adam 11y ago
The economics of solar panels in roads are horrible, given current technology. Here's an excellent engineering analysis of this exact project: https://www.youtube.com/watch?v=HOZBrHqTJk4 https://www.youtube.com/watch?v=HOZBrHqTJk4
- meric 11y ago
  I wrote a comment there. Panels on roads, if they can suffer being driven on well, can be economical when rooftop spaces run out. Rooftops are only sufficient for 25% of Netherland's electricity demand. I notice now there is a couple of inaccuracies but they are only minor ones financially. The benefit from saved real estate is too big. Local council governments may have access to its road real estate, but have no legal right to install panels on roofs. Netherland land value, per square meter, is €4,907. There is a local property tax is 0.05% - 0.3%. (http://www.shelteroffshore.com/index.php/property/more/property-tax-expats-in-netherlands-10540 http://www.shelteroffshore.com/index.php/property/more/prope...), and a wealth tax of 1.3% per year. Assuming 1.4% total taxes per square meter, the revenue received by the government is €68 per square meter. Since building the solar panel on the road means they don't have to build solar panels on real estate that can generate tax revenue, the benefit is €10 of generated electricity, plus the €68 of tax revenue that is preserved (assuming all municipal building rooftops are exhausted, already). That makes a payback of €78 per year. In 15 years, this would equate to €1170, compared to building a solar array on free land. The savings would be even greater compared to the local government renting rooftops to place solar panels.
hoopd 11y ago
Logistically speaking, there's a nightmarish level of complexity introduced here. Put a country's food distribution network on top of its energy production system? Put solar cells where you know they'll be constantly driven over by heavy machinery? Replace some of the most durable materials known to man (asphalt and concrete) with glass encased electronics? These things aren't impossible, but it's such an uphill battle that I wouldn't hold my breath. (http://jalopnik.com/why-the-solar-roadway-is-a-terrible-idea-1582519375 http://jalopnik.com/why-the-solar-roadway-is-a-terrible-idea...)
- joshuaheard 11y ago
  I gather from their website that the solar panels are embedded on top of the concrete roadway, so it would seem to have the same strength.
  - hoopd 11y ago
    Durability, not strength. Asphalt is very durable and it fails in predictable ways, it's difficult to design glass that fails gracefully. Yes, it's a surmountable engineering challenge but this project has more than it's fair share of things that fall in the "technically not impossible" or "we'll figure it out later" categories.
    - Retric 11y ago
      Asphalt is cheap, but not really that durable. 3-5 years in you generally see some cracking and should start matence. 5-7 years you generally need some patches and 15-20 you need to replace the surface. Though that's assuming good conditions and reasonable traffic patterns in some areas you need to resurface within 10 years. Concrete on the other hand generally lasts twice as long. From a material perspective glass is much closer to concrete than asphalt. Ex: http://en.m.wikipedia.org/wiki/Glass_brick http://en.m.wikipedia.org/wiki/Glass_brick the point being glass withstands sunlight and the elements without issue, it's being driven on that's going to be an issue. And luckily that kind of stress is much easer to simulate in a lab vs weathering. PS: That or ice which can handle heavy loads with little issue.
      - hoopd 11y ago
        Point granted, we use asphalt because it's a cheap and I should know better. I would still expect it to last longer than wildly complicated solar panel/computer/light displays that have many more modes of failure. For this to work you have to do several things to the glass at the same time, none of which come easy: make it strong, make it hard (probably need to get to 8 or 9 on Moh's hardness scale), make it tough, and have it grip rubber as well as asphalt does even when it's wet. Considering scratch resistant and grippy compete with eachother this is not looking hopeful.
JoeAltmaier 11y ago
In a country with sun nearly all day, on a bike path (not a road), run in a place without shade trees or houses. So they got a few KWH. If instead of a mile of 'solar bike path' you made a proper installation anywhere along that path in an empty lot, you'd do better, it would be cheaper, transmission costs would be less, and on and on. This fixation on "we're already using land area for roads; solar panels need land area; lets combine them!" is not an engineering decision - its politics and public relations.

Not sure why you are being downvoted, but I thing your comment makes a lot of sense, and I'd like to know why some think otherwise.

by guiomie 11y ago

Not sure why you are being downvoted, but I thing your comment makes a lot of sense, and I'd like to know why some think otherwise.

_Adam 11y ago

The economics of solar panels in roads are horrible, given current technology. Here's an excellent engineering analysis of this exact project: https://www.youtube.com/watch?v=HOZBrHqTJk4 https://www.youtube.com/watch?v=HOZBrHqTJk4

meric 11y ago
I wrote a comment there. Panels on roads, if they can suffer being driven on well, can be economical when rooftop spaces run out. Rooftops are only sufficient for 25% of Netherland's electricity demand. I notice now there is a couple of inaccuracies but they are only minor ones financially. The benefit from saved real estate is too big. Local council governments may have access to its road real estate, but have no legal right to install panels on roofs. Netherland land value, per square meter, is €4,907. There is a local property tax is 0.05% - 0.3%. (http://www.shelteroffshore.com/index.php/property/more/property-tax-expats-in-netherlands-10540 http://www.shelteroffshore.com/index.php/property/more/prope...), and a wealth tax of 1.3% per year. Assuming 1.4% total taxes per square meter, the revenue received by the government is €68 per square meter. Since building the solar panel on the road means they don't have to build solar panels on real estate that can generate tax revenue, the benefit is €10 of generated electricity, plus the €68 of tax revenue that is preserved (assuming all municipal building rooftops are exhausted, already). That makes a payback of €78 per year. In 15 years, this would equate to €1170, compared to building a solar array on free land. The savings would be even greater compared to the local government renting rooftops to place solar panels.

hoopd 11y ago

Logistically speaking, there's a nightmarish level of complexity introduced here. Put a country's food distribution network on top of its energy production system? Put solar cells where you know they'll be constantly driven over by heavy machinery? Replace some of the most durable materials known to man (asphalt and concrete) with glass encased electronics? These things aren't impossible, but it's such an uphill battle that I wouldn't hold my breath. (http://jalopnik.com/why-the-solar-roadway-is-a-terrible-idea-1582519375 http://jalopnik.com/why-the-solar-roadway-is-a-terrible-idea...)

joshuaheard 11y ago
I gather from their website that the solar panels are embedded on top of the concrete roadway, so it would seem to have the same strength.
- hoopd 11y ago
  Durability, not strength. Asphalt is very durable and it fails in predictable ways, it's difficult to design glass that fails gracefully. Yes, it's a surmountable engineering challenge but this project has more than it's fair share of things that fall in the "technically not impossible" or "we'll figure it out later" categories.
  - Retric 11y ago
    Asphalt is cheap, but not really that durable. 3-5 years in you generally see some cracking and should start matence. 5-7 years you generally need some patches and 15-20 you need to replace the surface. Though that's assuming good conditions and reasonable traffic patterns in some areas you need to resurface within 10 years. Concrete on the other hand generally lasts twice as long. From a material perspective glass is much closer to concrete than asphalt. Ex: http://en.m.wikipedia.org/wiki/Glass_brick http://en.m.wikipedia.org/wiki/Glass_brick the point being glass withstands sunlight and the elements without issue, it's being driven on that's going to be an issue. And luckily that kind of stress is much easer to simulate in a lab vs weathering. PS: That or ice which can handle heavy loads with little issue.
    - hoopd 11y ago
      Point granted, we use asphalt because it's a cheap and I should know better. I would still expect it to last longer than wildly complicated solar panel/computer/light displays that have many more modes of failure. For this to work you have to do several things to the glass at the same time, none of which come easy: make it strong, make it hard (probably need to get to 8 or 9 on Moh's hardness scale), make it tough, and have it grip rubber as well as asphalt does even when it's wet. Considering scratch resistant and grippy compete with eachother this is not looking hopeful.

JoeAltmaier 11y ago

In a country with sun nearly all day, on a bike path (not a road), run in a place without shade trees or houses. So they got a few KWH. If instead of a mile of 'solar bike path' you made a proper installation anywhere along that path in an empty lot, you'd do better, it would be cheaper, transmission costs would be less, and on and on. This fixation on "we're already using land area for roads; solar panels need land area; lets combine them!" is not an engineering decision - its politics and public relations.