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Comment by JimmyAxod | Hacker News Reader

> it currently costs about 1/10th the price to fuel up an electric car vs. a petrol car

Can you provide some data for that claim. Are we talking cost per mile travelled eg like for like?

I think it's closer than that?

Very roughly, UK prices are ~£0.2/kwh electrity and ~£2/litre of petrol. Per mile I make that £0.2 for petrol vs £0.045 for electric. Although you could probably get to the 1/10th figure if you always charged on the super-off-peak EV tarrifs.

Where are these places that give you massively discounted electricity at night?! Done away with around here many years ago… I wouldn’t rely on them always being there - obviously especially if everyone starts charging cars at night as it will cease being off peak and the reason for the lower price will be eroded.

It's common in france due to the amount of nuclear

Octopus (https://octopus.energy/) do 7.5p/kwh 00:30-04:30. I haven't used it, though, no idea if there are catches.

They are becoming more common here in the US. Although the one that I see most is more like a 3-4 hour peak period with very high rates and lower rates the rest of the day.

There are multiple electricity providers in the UK currently that have "EV tariffs" where they give you substantially discounted overnight/off-peak rates in exchange for a slightly higher daytime rate in order to encourage overnight charging. Often up to a maximum specified number of KWh per cycle.

In previous times they used to offer a tariff called economy 7 which worked in conjunction with so-called storage heaters. They would charge during off-peak times and provide heat during more active hours. (disclaimer, I've never lived in a property on such a scheme but definitely saw a few in my student days)

Assuming 7 pounds / gallon and 30mpg, a gas car would cost 23p per mile. Assuming 28.2p/kwh and 300wh/mi that comes out to about 8.5p/mi (figures pulled from Google for London, no idea if they're accurate, I'm in the US). In my experience that 300wh/mi is generous (my 2022 model y is usually closer to 350wh/mi in the summer driving downhill with the wind at my back and up to 450wh/mi in the winter). In any case, it doesn't seem to be anywhere near 1:10.

Do you drive like a maniac? Even here in Texas where you need to run the a/c full bore most tesla drivers see 250-300wh/mi.

There are charging losses to take into account as well. I think my gross is closer to 300 wh/mi lifetime than the 260 or so that the car reports.

My figures were not gross, sadly. :(

No, and I'm actually worried that I got a shit battery. It also charges at max 60kw. I just drove from Illinois to Denver and we got an average of ~350wh/mi (we had the A/C on but we tried to moderate it to save battery).

Energy pricing doesn't have to be constant - there's tariffs available which have cheap overnight electricity (eg Octopus Energy) - if you sign up now it's something like 7.5p/kWh, but some older contracts have it at 5p/kWh. You pay more during the day, but if you're charging a car a lot then it works out cheaper overall.

Looking at this, which has petrol costs from a month ago, it seems possible, although ⅛th is more realistic.

With today's price it would be 16p/mi for petrol. Their optimal May electricity price gives 1.88p/mi.

https://www.whichev.net/2022/05/13/is-it-cheaper-to-drive-an...

I pay $0.07 per kwh in Portland, OR. My Tesla Y gets roughly 3 miles per kwh. So 30 miles for $0.70.

At $5/gal and 20mpg, you'll pay $7.50 for 30 miles.

Cost per mile driven. 1/10th cost is on the more favorable end of the spectrum, but it's achievable if you can charge at home using an off-peak tariff. The ratio depends very much on what petrol MPG you compare it to.

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