Sweden is testing a semi-truck trailer covered in 100 square meters of solar panels::A Swedish manufacturer wants to harness green energy from a cargo trailer’s free real estate.

  • ElectricCattleman@lemmy.world
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    1 year ago

    Putting solar on moving vehicles makes no sense except for very specific use cases.

    Install those same panels on the ground and you can point them at a good angle for sunlight capture 24/7, don’t have to literally carry the weight of them everywhere, don’t have to worry about them getting dirty all the time from moving around winter roads, and are much easier to repair.

      • n0m4n@lemmy.world
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        1 year ago

        Solar ditches make more sense. Carrying solar panes add weight and air resistance. The trailer area is 416 ft which can hold ~33 panels if panel configurations are optimized for a trailer. Weight will be 3000 lbs, which cuts the tare payload by 6%. This is not enough electricity to run a semi with two drivers splitting driving responsibilities, running day and night, and in weather that does not have power for the cells.

        Trains are the most efficient system that we have. I wonder how the math would work for trains? I expect that it would be a net gain, but the added complexity of connecting and disconnecting for each car as the cars get switched in yards would be a nightmare. Once travelling, there is little braking and acceleration, which lowers the power demands.

        • bitwolf@lemmy.one
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          1 year ago

          Yes but sadly no one wants to talk about trains.

          It’s really killing the Utopian dreams of public transport

    • GiddyGap@lemm.ee
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      1 year ago

      Pretty sure these solar panels aren’t just your regular residential or commercial building panels. They are specially made for this purpose.

      • CaptPretentious@lemmy.world
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        1 year ago

        Those don’t exist.

        Amount of power that can be generated is dictated by the angle to the Sun. You need to be perpendicular. Panels on the ground can slowly move and rotate to kind of track the sun. Or you put a bunch of mirrors and make a tower made of solar panels.

        Solar panels on roof tend to be fixed infrastructure. You get what you get.

        So if they apply panels to a vehicle you have two options. Flat or angled.

        If they’re flat and the only time you’re ever going to get the maximum amount of power from them is during noon when the sun is directly above your vehicle. If angled that means the height of the vehicle has changed and they direction that they work is very dictated. If they track the Sun then they’re probably going to waste more power than they can ever produce by constantly moving because you’re on a vehicle that’s constantly moving.

        • GiddyGap@lemm.ee
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          1 year ago

          Those don’t exist.

          No one said it does.

          Generally speaking, solar panels aren’t optimized for near-constant traveling. As such, it’s “fairly involved from a technical point of view,” said Falkgrim. Despite only recently starting prototype testing on Sweden’s public roads, he explained the project is “about seeing if the solution makes sense, and so far we believe it does.” Although such a design isn’t expected to become widespread on roadways for a few years, Scania’s initial testing shows the tech is not only feasible, but promising.

          • jj4211@lemmy.world
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            1 year ago

            While they could do things to mitigate the angle of incidence, ultimately that same photovoltaic material will fare better angled consistently toward where the sun might be. If you’ve run out of room everywhere else, sure, time to look at trailers. But so long as we have spare other places, those are better places.

            The trailer might be going through shaded areas, there’s only so much optics can do to correct for angle of incidence, and the added weight means we are using energy to move them around when they’d be better off stationary anyway.

            Even residential solar is a dubious proposition, since you have to work around roof lines that are rarely optimal for solar. In that case it can make some sense for owning your own generation, particularly with battery, to go “off grid”, but I have a hard time imagining similar for the trailer.

            • DeanFogg@lemm.ee
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              1 year ago

              Depends on how much power you can efficiently harness I’d imagine

              A 220 watt solar panel will somewhat efficiently charge a 12v battery on a clear day

              An electric car uses about an 800v battery(s) which is about 67 normal batteries. Let’s go ahead and say a small truck would take twice that and hey to make it a round number let’s call it 2000v. That means you would need a solar panel that can produce 440,000 watts or .44 Megawatts.

              Some Google fu shows that to harness an entire megawatt(1 million watts) you’d need about 5000 conventional solar panels which on the ground would take up about 5-10 acres. Pretty impractical to put half that on the back of a truck I’d say.

              You’d have to have some extremely efficient solar panels to make it practical methinks. Might work on smaller cars though. Anyone feel free to jump in here and get me with an epic slam though

            • GiddyGap@lemm.ee
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              1 year ago

              Yeah, it certainly seems like a challenge. I’ll be interested in seeing where they go with it.

            • CaptPretentious@lemmy.world
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              1 year ago

              Thing is, we’re no where close to running out of room. There’s lots of land to use. I cannot speak for every country, but the US for sure has vast areas of nothing. A truck stop with a solar array nearby storing it for when the trucks stop buy to me makes way more sense to me at least.

          • CaptPretentious@lemmy.world
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            1 year ago

            Those don’t exist.

            No one said it does.

            Pretty sure these solar panels aren’t just your regular residential or commercial building panels. They are specially made for this purpose.

            This you?

        • BakedGoods@sh.itjust.works
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          1 year ago

          Ah yes. The old “this isn’t an optimal solution that will solve all problems so no one should be working on it”-argument. You must be fun at parties.

          • CaptPretentious@lemmy.world
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            1 year ago

            Listen this isn’t mixing drinks or some opinion piece were there’s no one clear way. Things cost money. Every company that would seek to implement this is going to be looking at an ROI. Suboptimal numbers is going to make the project look bad and waste a bunch of money. Sorry if I’m ‘not fun’ because I’d rather have functional solar power than the appearance of solar power.