this post was submitted on 07 May 2024
907 points (98.4% liked)
xkcd
8791 readers
127 users here now
A community for a webcomic of romance, sarcasm, math, and language.
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
The sun gives you around 1500W per m2. If sun shines at maximum brightness for 24 hours, you get 36kwh per day. That's enough to fully charge a small EV every day. That's a spherical chicken estimate.
Bringing this to numbers that exist in the real world, the sun will only give you about 20% of that over the course of the day, and the panels are around 20% efficient. You'll get more like 1.4kwh per day per m2. You can double or triple that, depending on how much surface area you can cover. An EV can get around 3 miles per kwh, so tripling that number will get you 12 miles. Considering the extra costs involved (both in buying the panels and adding weight), it's not even worth it as a supplementary source.
There's some possibilities for RVs, which have a lot of roof space for panels, tend to sit in one spot for days or weeks, and have other power usages that are a lot less than driving. Otherwise, put the solar panels over the parking places and roadways, not on the cars.
The benefits increase as the efficiency of the car increases though, check out Aptera. They say they get 10 miles per kwh, and they have a lot of surface area for panels. Enough that in ideal conditions they say they get 40 miles per day from solar. It is a bit different looking though.
https://aptera.us
It's also a three-wheeler, which gets around US safety regulations. It gets registered as a motorcycle or autocycle (depending on how your state handles it). However, it's still an enclosed metal box. There's not a lot of good data, but it's arguably better to be sitting loose on a motorcycle with a helmet and safety gear as opposed to being crushed inside a sardine can.
There's a certain point of shrinking cars where you have to ask "why not use an e-bike?", and this is that point.
Well, it has a carbon fiber frame with a crumple zone in the front. They are going to put it through 3rd party safety testing. It won't be as safe as a big SUV, sure, but I think it will be safer than an ebike. It also protects you from weather and has 35 cubic feet of storage in the back. I think ebikes are great too, but this does have more of the advantages of a car.
You know how the Internet made fun of Stockton Rush for using carbon fiber in a sub, which is a compression structure? Similar thing going on here. Carbon fiber is a great material for tensile strength and lightweight. It can be used in compression structures, but it needs more careful engineering to pull it off. The benefits do not always outweigh the costs.
As a more general issue, if a car the size of a Geo Metro or smaller can't be safe on roads, then motorcycles and bikes can't be, either.
Well, I just said carbon fiber, but to be more exact it is forged carbon SMC, so yeah, careful engineering involved. Same stuff Lamborghini is using for some structural components, so probably fairly fit to purpose.
https://en.m.wikipedia.org/wiki/Forged_composite
Cuz you can haul more, camp inside of it with the tent mod, travel further and faster.
They’re planning 250, 400 and 1000 mile versions. I’m also not taking an e-bike on the highway.
I'm not sure you can haul more. Cargo e-bikes can do a lot more than you think.
Ya I saw that cybertruck to cargo bike comparison. I automatically went to the mountain bikes. We don’t have the same cargo bikes the Dutch have but there is a guy around here with a cargo e-trike. I bet it’d be close. But the car can also take a second passenger not in the cargo space.