Why don't electric car manufacurers put solar panels on the car roofs? - eviltoast

Honestly it seems like a no-brainer to me to put a solar panel on the roof of electric cars to increase their action radius, so I figured there’s probably one or more good reasons why they don’t.

Also, I acknowledge that a quick google could answer the question, but with the current state of google I don’t want to read AI bullshit. I want an actual answer, and I bet there will be some engineers eager to explain the issues.

  • mortalic@lemmy.world
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    5 months ago

    While most of the points are covered here, and it’s likely true that the cost to add the panel and micro inverters is high, (I built a small two panel one battery off-grid system for about $4000 to power a chest freezer)… I have a counter point that I feel should be considered.

    While it’s true that it isn’t going to extend driving range by much, my thought is that it is still worth it. Take these examples:

    Drove to great wolf lodge in the summer, left car in parking lot for 3 days without charge. It lost several %.

    Left car in an airport lot for a week lost even more power.

    Drove to NorCal, left car at Airbnb driveway, had to find charging despite the car sitting in very bright sunshine for 4 days.

    Car camping

    Apartment complex parking (literally one of the main negatives about EVs)

    All of these would benefit from trickle charging, even if it was just to prevent the drain of sitting.

    • eyeon@lemmy.world
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      5 months ago

      the question then becomes how much weight are you adding/energy are you consuming by having to carry the weight. I honestly don’t know and considering how heavy batteries are it is likely not that significant, but if you are only getting a few % charge a day then anything eating into that is going to hurt.

      I still see some merit in a more utility style vehicle where you do expect to take it out camping, but for a daily commuter I think most people would prefer the sunroof to the trickle charging.

      Also as an apartment dweller… I just wish they’d make normal wall outlets more available. Not everyone needs a proper fast charger but only having a few inconveniently located ones to fight for also sucks. But if more spots could just plug in and slow charge that would be a huge improvement

    • Tja@programming.dev
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      5 months ago

      What car do you have? I worried about this for my Model 3 back in 2021, when it had some vampire drain. But if you don’t open the app on your phone, the car goes into deep sleep and it can be parek for weeks without a single 1% loss.

    • TheFriar@lemm.ee
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      5 months ago

      You seem to know what you’re talking about and I want to piggyback off this question to ask why they don’t harvest energy from the brakes or the wheels spinning. I always heard braking once could power a home for a day or something. And I assume if you put a passive spinning wheel power generator on each of the four wheels, you’d also produce a lot of energy. Are all of these things too heavy to have any benefit? Plus the wind passing the car as it drives…it just feels like there are a lot of missed opportunities for new energy production as the car moves that aren’t taken advantage of. What’s holding these ideas back?

      • joostjakob@lemmy.world
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        5 months ago

        Electric cars do charge when braking. Obviously the energy recuperated is less then waht was needed to drive that fast in the first place. Using driving wind would just increase the energy needed to drive that speed and would be net negative.

      • ryathal@sh.itjust.works
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        5 months ago

        Most electric cars have regenerative braking. It’s not magic though, it takes more energy to speed the car back up than it recovers. Regenerative braking just makes stopping less bad for range. Sure you can go down a mountain and gain a lot of power, but not enough to go back up the mountain.

    • COASTER1921@lemmy.ml
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      5 months ago

      The problem is that this isn’t really even trickle charging. Customers would absolutely complain and say it’s not working because it couldn’t charge the battery more than 1-2% in an entire day of sun. EV batteries are 60kWh+ yet getting more than 2kWh/sq meter daily from residential panels is hard for much of the US. Add to that the:

      • weight of panels
      • cost of panels
      • heat trapped in the car from having a roof literally designed to absorb solar radiation
      • fragility of panels (although all these glass roof EVs have that problem already) And it’s really not worthwhile.

      One solution to the apartment street parking problem is adding charging ports to streetlights (they do this in Europe). But for most of US apartments there’s already dedicated parking space so also space for chargers. The unruly size of new vehicles is a much bigger problem in my mind, if there were actual motivation to fix this problem in government it would already be solved through some tax credits.

    • mortalic@lemmy.world
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      5 months ago

      Replying to my own comment because I just stumbled upon uncle Rich doing exactly this on a cheap chinese EV truck.

      It’s kind of a fun take on the crappy truck too. youtube link