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Comment by squishy47 | Hacker News Reader

$20k to install a 22kW charger!!!! i was quoted £1300 (uk) to have one fitted and i thought that was expensive! to reply to another comment about why a 22kW is needed. if you're on a flexi tariff where energy price is super cheap from like 12-4am then having it fully charge in that time is needed to maximise the best price

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In the UK you have the advantage of easy access to 3 phase electricity, most houses can simply pull 2 more wires from the mains and have it. Whereas in the likes of Ireland you need a special setup and massive extra cost to get 3 phase.

Having a 22kw charger at home is amazing especially for only £1300!

Emm. No we don't. We only have a single phase supply to the home. At least traditionally, new homes may be built to different standards.

Ours comes into the house via a very scary looking lead sheathed TN-S cable.

Hmm, fair enough, maybe it's only in large towns and cities. The pricing you got seems a bit suspect in that case because you would need 3 phase to run a 22kw charger and if you don't have easy access to 3 phase then the cost would be quite a bit higher as new wires would need to be added.

The charger alone would cost around 1000 (if not slightly more) so I can't imagine them doing the amount of required work for 300 pounds.

It's actually usually the other way around. In a rural location you are much more likely to have access to a 3-phase supply. Farms for example almost always have a 3 phase supply for running pumps, motors and heaters etc.

Yes we do. Well, theoretically anyway - you know those electricity poles with 4 cables above each other? That's 3 phase. Usually each house just gets one phase but I guess theoretically having 3 phase would just be a matter of connecting up the other wires too.

I'd be surprised if you could actually convince suppliers to do that for a house though, and definitely not for £1300.

Ha, my cables are all underground, making life harder.

Some DNOs are only installing 3-phase now - they'll just connect a single phase up, but the wiring will be ready for three.

Not mine, of course. Bitter about that.

This is the same the world over. Power is generated and distributed as 3 phase because it is better for the generators and it makes better use of the power cable since you don't require a neutral for a balanced 3 phase load.

$20k problably includes the cost of digging tranches and lay new cables. Here in France it's tops a few thousand euros if you want 36kVA, but that doesn't include civil engineering.

22kwh is 90 amps at 230 volts. Surprised is 20k to install a single one of these.

In the us most newer homes have 200+ amps of service providing 48kw of peak electric capacity.

Aren't US homes running at 120 volts?

22kw at 230 volts would be ~95 amps. 22kw at 120 volts would be ~183 amps. 48kw at 120 volts would be 400 amps.

No, US homes are typically 240V split-phase: https://en.wikipedia.org/wiki/Split-phase_electric_power

Aren't US homes running at 120 volts?

Yes . . . and no. In North America, homes are actually supplied with 240V. A split-phase system with a centre-tap transformer is then used to create two 120V "phases." So, your typical outlets will be on one of two 120V phases. However, there are usually a couple of 240V outlets as well for things like electric stoves, and clothes dryers. So, in short, single phase 240V is available in essentially every U.S. household.

The cars, themselves, usually require 3-phase 240V to do 22kW. You are highly unlikely to have access to that in a U.S. home.

no, 22kW is 32A as we use three 240V (to neutral, so around 400V between phases) phases here. Most home here have 40A capacity (mine does).

You have to pay for the introduction box, which need to be changed in my case and is about 7000$ [1] and you have to may for each extra A capacity, which is 150$ per A. So 32*150 is 4800 + 7000. And that's only to change the capacity of what we call the "introduction". Then I have to change the cabling inside the house up to the breaker room and install a charging station. The whole thing is about 20k

[1]: https://www.romande-energie.ch/images/files/conditions/2021-...

I don't get what you are saying.

You have 3x40A. Your biggest user is occasional 3x25A. So you have 3x15A available almost all the time. 3x16A is 11kW, you can tell your car or charger to go no more than 3x13A or 3x10A or whatever, this can even be automated by most charging stations. When you have your local EV meetup with 3 cars and all want to charge then either take turns or have all charge at 3x13 each and switch the heating off for that time.

I have this at home [0]. It plugs into a regular (red) 3x16A socket, has RCD protection built in and needs 0 installation cost and no nonsense about utility needing to come and do anything.

Surely you have one of those red 3x16A or 3x32A sockets in your garage/workshop wherever? If not your local electrician can put it in for xx instead of utility doing something unneeded for xxxx or xxxxx.

[0] - https://eauto.si/metron-shop/product/pc05t-3x16a-3-phase/

As I said I am at the limit already, I have my home lab and a small server farm for work, I also have a workshop. I already cannot put everything on, if I use the workshop, you cannot use the kitchen oven for example. I realize 11kW is enough for most usage, but in my case, even that requires changing infrastructure, which is expensive.

Most chargers have Dynamic Load Management readyness where they have a Modbus power meter at your main circuit breaker and makes sure the charger only uses available power. So you can switch on your oven and car will automatically back off.

For this kind of consumption tho I would consider installing solar panels if that is possible/feasible.

I have an 11A charger and some 5kW solar panel setup, and I am lucky enough that I'm able to charge during the day the trips I make early in the morning just with solar.

He's talking nonsense. He's talking running a new line from the nearest electrical pole to his house. That is almost never necessary.

This price is only applicable in the UK if you already have 3-phase electricity to the property, which is rare. 7kw otherwise.

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