Scientists develop mega-thin solar cells that could be shockingly easy to produce: ‘As rapid as printing a newspaper’::These cells could be laminated onto various kinds of surfaces, such as the sails of a boat to provide power while at sea.

  • frezik@midwest.social
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    11 months ago

    A camper van. Which has electrical use for things besides turning a motor. Yeah, that’s useful, but it doesn’t exactly help your case.

    Under optimal conditions, the sun gives us 1000Wh per square meter. Let’s say you have a 100% efficient solar panel. A semi truck trailer has a max of 42 sq meters on top of its trailer. So you get 42kWh out of this.

    It takes about 280kWh to keep a semi truck at cruising speed on the highway. Thus, in this most optimal scenario, it would give you an additional 15%. Even this assumes there is no additional aerodynamic drag from the panels, mounting hardware, or wiring. It wouldn’t take much to completely blow that 15% away.

    If it’s a cloudy day, all of it is now deadweight, and now hurts more than it helps. If you don’t drive on the equator, its output drops and it now hurts more than it helps. If you have solar panels that actually exist that do around 20% efficiency instead of 100%, it now hurts more than it helps.

    I guess we could move the Earth closer to the sun. Won’t help our global warming problems, though.

        • JungleJim@sh.itjust.works
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          11 months ago

          You first said is was physically impossible. I’ve shown you it wasn’t and predicted you’d move the goal post from possibility to practicality. And you did. Thanks for proving that you don’t really care about whether it could even possibly work, but just that you wanna dunk on excitement and be right on the Internet. Have a good day.

            • JungleJim@sh.itjust.works
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              11 months ago

              “There are physical limits at play to how much power this can provide. No amount of technological improvement can break them.”

              Also, the fact it powers the motor for the camper AND all the appliances and such just proves the viability that much more, as the extra power draw is still supported by the camper’s solar power system.

              • frezik@midwest.social
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                11 months ago

                Yes, there are physical limits. It cannot provide enough power to justify having it only for the purposes of turning a motor. A camper van can justify it because it has lots of uses for electricity besides turning a motor, and as long as you’re paying the cost anyway, might as well connect it to the battery charging circuit.

                You started this conversation with:

                Or imagine shipping containers covered in these powering the trucks that haul them! Or trains! Even boats. Basically any kind of self powered transit, especially ones with greater surface area.

                All things that primarily turn a motor. None of these are feasible to be powered this way.

                • Meowoem@sh.itjust.works
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                  11 months ago

                  Your physics isn’t terrible but you’re making absurd leaps into nonsence with the rest, you also don’t seem to have practical awareness of trucking logistics.

                  Here’s a thought experiment, if sticking news paper to the outside of your truck was proven to give a 5% fuel cost reduction how long do you think it would take before you see a truck covered in news paper? Probably hours at most, truck drivers don’t like stopping to piss because the extra fuel required to accelerate to highway speeds cuts into their margins so you can be damn sure that if there was an inexpensive way to reduce the cost of charging their truck everyone will be on that.

                  Also trunks have a lot of stuff beyond the motor, security and logging systems for example as well as various forms of climate control. Also being able to leave a vehicle idle and have it’s fuel slowly increase instead of decrease / denature is a huge thing in a lot of situations.

                  If course is not going to make a truck that can drive a heavy load without recharging but if its only going to cost the same as a paint coating and can supply a slow trickle then it’ll be a very popular product.

                  Even more so for things like agricultural machinery, leasure vehicles such as campers and boats, or anything with large gaps between uses.

                  • frezik@midwest.social
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                    11 months ago

                    So let’s think about how a hypothetical electric truck would charge throughout the day. Driver makes a 20 minute stop and there’s a 350kW charger available (about the max of what’s out there for this sort of thing right now). They’ll get 105kWh of charge out of that.

                    The top solar panels I can find at the moment are 540W and take up 2 sq meters each. So a 42 sq meter can have 21 panels for 11kW. That’s the power they’d be rated for in direct sunlight on a bright day.

                    Even if we assume they have that direct sunlight for 12 hours straight (they won’t, not even in equatorial regions), they’ll get 136kWh out of that per day. Only a bit more than what they’d get out of a 20 minute stop.

                    US regulations require that a driver take a 30 minute break after 8 hours of consecutive driving. I also understand that this rule is broken all the time, but I don’t feel the need to pander to exploitative and dangerous behaviors on the part of trucking companies.

                    Then we get to the cost. Those panels will be around $5000 for the set, and there are significant labor costs involved, too. Call it $10k/trailer to save a 20-30 minute stop each day that the driver will probably take, anyway.

                    There’s also significant weight added, which reduces how much cargo they can carry. The factor you’re talking about in getting the truck back up to highway speed just got worse. The panels ones noted in OP would be extremely lightweight, yes, but they also cut the power delivered in half.

                    None of this can happen until the industry electrifies. Current electric semi trucks are barely suitable, and there needs to be some improvements in battery tech before they can be.

                    This idea doesn’t even look good on paper with unrealistic assumptions made in its favor. Put the solar panels at the charging stations, not the trucks.

                    Or better, forget about long haul trucking and replace it with electrified rail. Mount the solar panels on racks above the trains, not on the trains.

                • JungleJim@sh.itjust.works
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                  11 months ago

                  So you did say that. But you just told me you didn’t. You’re confusing. I also showed you a motor powered this way yet you say it isn’t feasible. So I really feel like I’m done with this conversation. Good day.

                  • frezik@midwest.social
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                    11 months ago

                    Not my fault if you don’t understand the difference between “impossible” and “infeasible”.