this post was submitted on 19 Jun 2024
1137 points (100.0% liked)
xkcd
10093 readers
38 users here now
A community for a webcomic of romance, sarcasm, math, and language.
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Real answer: power density. Pound for pound, gas still contains more energy than our best batteries. The weight of energy storage is still a massive deal for anything that cannot be tethered to a grid or be in close practical proximity for frequent recharging, from rockets, planes and cars (sometimes) to chainsaws and lawnmowers (sometimes).
Density is relative to efficiency, and electric wins
What i cannot understand is people trying to defend something that is clearly worse,
Googling tells me that:
So the math here says electric gives you (0.97 * 77%) 0.75 MJ/kg output and gas gives you (46 * 30%) 13.8 MJ/kg output. Plus, as someone else said, spent gasoline no longer weighs you down.
I like the idea of electric, and I want to see it replace gas as soon as possible, but fair is fair.
And let's not forget that fueling your car requires a tank, a decently sized pump and 2 minutes of your time. A quick charge will hopefully charge your battery to 80% in 30 minutes, while giving you less km and running 300kW of power through hefty cables and big transformers, consuming the amount of energy that a family house consumes in a few days.
(And yes, battery manufacturing and disposal consume enormous amount of resources)
Electric and gas have different situations in which they shine. Gas/diesel engines are just a bunch of steel and some control chips, optimized in more thana century of technological development if we couls develop carbon neutral fuel, electric cars would not be needed. Unfortunately, it woulf be difficult to do at scale of current fuel consumption. More (electric, battery-less) public transport, less road goods transportation, more nuclear, electric for vehicles that move 100% of the time (delivery and logistic vehicles) and carbon-free fuel for other kinds of vehicles (personal transportation) is a good balance, in my personal, ignorant, armchair opinion.
I dunno, I've never looked into them. How do they stack up against electric motors in everything else, and is the hydrogen expensive to get?
The comment you're replying to is deleted, but from your comment I assume it was about hydrogen as fuel?
Hydrogen fueled vehicles are generally electric, using a hydrogen fuel cell, rather than being internal combustion using a hydrogen engine. Compared to battery electric, hydrogen has the benefit of fast refueling and higher energy density, but has the drawback of difficult storage and lack of refuelling infrastructure.
As a vehicle fuel, I think hydrogen does have a future, but only in commercial/industrial, particularly shipping. Semis already have predictable routes and stops/depots, and building hydrogen refuelling stations into those depots wouldn't be too complicated.
Hydrogen passenger vehicles, with gas stations being replaced with hydrogen stations, will never happen.
How do you think about hydrogen cars? They have better fuel density, and hydrogen is renewable.
The argument that I've heard is that electric cars aren't actually cleaner because of the pollution caused by mining the minerals required for the batteries.
I'm sorry but I'm too lazy to dig up links to back up my claim. But you are correct in that electric vehicles pollute far more being produced than combustion engine cars, however the electric vehicles gain that back over it's lifetime if your charge from mostly non-fossil sources. The figures I have read says that over the lifetime of a car, electrics output 70% less CO2 than combustion cars, and that includes the production of each of the cars.