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Solar roadways were always a terrible idea. Solar railways would have the same problem. Putting solar above parking lots and parking decks is a much more viabl

Solar roadways were always a terrible idea. Solar railways would have the same problem. Putting solar above parking lots and parking decks is a much more viable way to use vehicle-related infrastructure for solar. Using desert habitats are probably superior since we are in a climate emergency and need to build as much solar and wind as possible as fast as possible. Ground solar is cheaper than elevated solar as I understand it.

ben_w 5y ago
> Solar roadways were always a terrible idea. Solar railways would have the same problem. As I understand it, the problem was it was too expensive to make it sufficiently damage resistant, that damage being continuous wear from all the traffic. Just outside my window, there is a tram line. Grass grows in the spaces between the rails. I suspect you could put normal panels in those gaps where grass currently grows, and most of the panels would last just as long there as they would on a rooftop.
- lazide 5y ago
  Hmm. And how much square footage do you estimate that would cover? How would you run electrical lines by and through the constantly moving (expansion/contraction, as well as vehicle weight) heavy steel elements? How would you deal with the constant maintenance that must be done on everything from light rail to heavy cargo lines? How would you make sure all your panels weren’t destroyed in one pass by a drug connector? Roads are at least as bad, and near as I can tell, there is literally no road surface (from hardened steel to concrete to glass to asphalt!) that won’t get potholes and other damage decently quickly. And they don’t have any sensitive electrical connections or need clear sunlight to do anything useful.
  - ben_w 5y ago
    > Hmm. And how much square footage do you estimate that would cover? USA has 257,722 km of 1,435 mm gauge track, so… about 3.9 billion square feet there. The EU is a bit less, but similar (208,211 km). Worldwide is 1,370,782 km, various gauges. Roughly 21 billion square feet? Should be good for a combined nameplate capacity around 393 GW. > How would you run electrical lines by and through the constantly moving (expansion/contraction, as well as vehicle weight) heavy steel elements? The trains and trams around here are electrically powered, so that’s already solved technically, and in cases like mine the solution has already been implemented. I have no idea how the other stuff might influence costs.
    - lazide 5y ago
      None of your numbers line up. You’re using US track numbers, but essentially zero US track is electrified. The little bit that is electrified is often underground and all of it is high voltage and won’t work with solar like that. Next to said tracks though are millions of acres of land that wouldn’t have all the maintenance issues and would actually work? It’s a similar issue with solar roadways - it’s a really impractical place to put solar; not even close to worth it maintenance wise or efficiency - and you pretty much always have better options literally 10 ft away.
      - ben_w 5y ago
        > None of your numbers line up. You’re using US track numbers, but essentially zero US track is electrified. Doesn’t matter. The engineering solution is known (as I type I am literally looking at overhead power cables above the street, powering one of Berlin’s tram lines). Use that class of existing solutions rather than asking me to reinvent it badly. > Next to said tracks though are millions of acres of land that wouldn’t have all the maintenance issues and would actually work? Great, so use that too, if you like. But the ask I was responding to was the idea we should use land which is already in an unnatural state.
        lazide 5y ago
        That’s literally not how any of that works at all.

ben_w 5y ago

> Solar roadways were always a terrible idea. Solar railways would have the same problem. As I understand it, the problem was it was too expensive to make it sufficiently damage resistant, that damage being continuous wear from all the traffic. Just outside my window, there is a tram line. Grass grows in the spaces between the rails. I suspect you could put normal panels in those gaps where grass currently grows, and most of the panels would last just as long there as they would on a rooftop.

lazide 5y ago
Hmm. And how much square footage do you estimate that would cover? How would you run electrical lines by and through the constantly moving (expansion/contraction, as well as vehicle weight) heavy steel elements? How would you deal with the constant maintenance that must be done on everything from light rail to heavy cargo lines? How would you make sure all your panels weren’t destroyed in one pass by a drug connector? Roads are at least as bad, and near as I can tell, there is literally no road surface (from hardened steel to concrete to glass to asphalt!) that won’t get potholes and other damage decently quickly. And they don’t have any sensitive electrical connections or need clear sunlight to do anything useful.
- ben_w 5y ago
  > Hmm. And how much square footage do you estimate that would cover? USA has 257,722 km of 1,435 mm gauge track, so… about 3.9 billion square feet there. The EU is a bit less, but similar (208,211 km). Worldwide is 1,370,782 km, various gauges. Roughly 21 billion square feet? Should be good for a combined nameplate capacity around 393 GW. > How would you run electrical lines by and through the constantly moving (expansion/contraction, as well as vehicle weight) heavy steel elements? The trains and trams around here are electrically powered, so that’s already solved technically, and in cases like mine the solution has already been implemented. I have no idea how the other stuff might influence costs.
  - lazide 5y ago
    None of your numbers line up. You’re using US track numbers, but essentially zero US track is electrified. The little bit that is electrified is often underground and all of it is high voltage and won’t work with solar like that. Next to said tracks though are millions of acres of land that wouldn’t have all the maintenance issues and would actually work? It’s a similar issue with solar roadways - it’s a really impractical place to put solar; not even close to worth it maintenance wise or efficiency - and you pretty much always have better options literally 10 ft away.
    - ben_w 5y ago
      > None of your numbers line up. You’re using US track numbers, but essentially zero US track is electrified. Doesn’t matter. The engineering solution is known (as I type I am literally looking at overhead power cables above the street, powering one of Berlin’s tram lines). Use that class of existing solutions rather than asking me to reinvent it badly. > Next to said tracks though are millions of acres of land that wouldn’t have all the maintenance issues and would actually work? Great, so use that too, if you like. But the ask I was responding to was the idea we should use land which is already in an unnatural state.
      - lazide 5y ago
        That’s literally not how any of that works at all.