EV Charging in the UK

I was surprised how common it is in the UK to have instant electric water heaters for showers, often 10kW or more. Here is a typical example:

While in some countries it is a necessity for a family to own one or more cars, this is not the situation in large parts of Europe. This reduces the number of EVs that needs charging in an area.

What is the EV consumption ? If one believe the EV manufacturers claims, you should be able to drive 5-6 km with 1 kWh. At 6 km/kWh then 240 km translates to 40 kWh. A 3 kW (13 A 240 V) socket could barely supply that in 14 hours each evening and night.

However that daily 240 km sounds quite a lot, i.e. commuting 120 km in one direction. No way, that is not a realistic average commuting distance in UK. That would be spending more than 3 hours in the car each day.

Perhaps they are not as expert as you give them credit for.

It trips if the flow of current in the Live and *Neutral* do not balance out to within some fairly tight tolerance typically 10mA, 30mA or 50mA.

IOW any current escaping to Earth means it trips.

On average it may well be right since space heating and about half of all cooking is done by mains gas or kerosene. My own house only the computers, kitchen appliances and electric lights are on electricity.

The annual UK national average is claimed to be about 4kWhr/day. See

The 2kW number is just hopelessly wrong! When the 1960's estates were built night time Economy 7 electric central heating was all the rage (the infamous nuclear electricity too cheap to meter promise) so the distribution network in towns would have been sized accordingly.

Even prior to that the national grid system must have been designed to handle electric cookers all being run at roughly the same time to cook evening meals. They are hardwired because they are 6kW heating elements (but again only on for a proportion of the time). Some modern designed cookers will plug into a 13A socket being less than 3kW peak load.

It is a time average. The distribution network can handle a lot more. Electric 10kW flash heaters for instant hot water and showers are quite common here. The duty cycle they are used for makes all the difference.

Same with kettles. It is a 3kW load but only for a couple of minutes.

Well, R.C. was told, so we'll just have to leave it at that.

Oh, picky picky picky :)

Yes indeed, and so have I.

I was surprised at how well I held up, particularly due to the unseasonable weather and that I went on the Wainfleet-All-Saints bypass, of current front page news fame!

I was fully expecting to have to doze for an hour at one or two service stations, but to my surprise it wasn't necessary.

I don't remember seeing those 2A plug/sockets.

OTOH I have seen mains wiring consisting of a two core cable covered in a lead sheath. The latter was the protective mains earth, and junction boxes gave/give me the screaming heebie-jeebies. Fortunately it wasn't connected to any live circuits.

You are lucky to find a green campaigner that understands that kW != kWh. It is impossible to get them to answer "if we install X GW of wind power, how much conventional plant can we remove?".

Well, that's not quite true. They answer, but the answers are invariably wrong.

That does rather assume there is not also a move to shift domestic heating away from gas or oil to electric. We would certainly need more generating capacity for any significant shift.

Distribution networks are sized based on statistical models - so they will calculate an average load over 24 hours to assess total demand. However they do also anticipate significantly higher peak demands. New properties are typically built with a 24kW electrical supply (1 phase,

PME (Protective Multiple Earthing) distribution systems supply the property with a "PEN" conductor - Protective Earth and Neutral. This is the main neutral as derived at the substation - however as its name suggests it is bonded to earth at the substation, and then at regular intervals along the distribution network. Its the preferred solution for new supplies since it delivers a reliable and low impedance earth path. Many older properties however will have TN-S earthing systems, (i.e. separate earth delivered from the sub station to the property). Older rural properties may well have no earth supply from the network at all (TT systems)

For more detail see:

Generally more caution is used when exporting a PME earth to outside circuits. The risk of neutral disconnection (and not line also) is considered a fairly low likelihood event. However precautions taken typically include extending the equipotential zone to where you are exporting power. This is not ideally suited for EV charge points outside.

No not really. In many cases you simply convert to TT with local RCD (GFCI). Hence any ground rod only needs a stable earth impedance under the low hundreds of ohms, and that is relatively easy to achieve.

See:

Note also that there are specific additional rules for EV charging point protection (special classed of RCD etc) designed to mitigate some of the perceived problems.

Street charging is a more difficult problem to solve without significant new infrastructure. Hopefully at some point there ought to be a larger network of fast chargers that can be used to charge on demand, rather than overnight. Making for something closer to the current normal practice of stopping off at a filling station to refuel.

The government (and I use that term loosely) is making noises about preventing gas being supplied to new-build housing estates.

The Nigerians have invented solutions to that, as occasionally seen on the news.

The number he has might well be right as a time average across a year for a household. Typical numbers for various sorts and sizes of UK house are online here in terms of energy use in kWhr per household per year.

It is about 3-4MWhr per year per household or 8-11kWhr/day on average.

That translates to a 300-500W average daily load which seems a bit high to me. My own daily peak load is about 350W average and night time base load is well under 100W unless I am running something on the computers.

Interesting that several green sites quote the 6kWhr/day figure when working out how many homes a new green energy PV farm can supply. (at least when the sun is shining or the wind blowing hard enough)

But I am fairly sure that the distribution system is good for delivering considerably more than that as peak transient load without any problems at all. It happens with 3kW kettles at half time every cup final day.

They have to prep the generating system ready for the exact moment and then engage the rapid response kit and pumped storage at full tilt.

That's good compared to my road in similarly leafy suburbs.

Currently I'm parked 50m away, it has been 200m away and/or on the other side of the road and/or across a busy road.

And then there are people living in houses converted into flats.

EVs would do for many of my journeys, but, crucially, not for all. Having a hybrid for some journeys is not practical.

And the effect of hills shouldn't be neglected, particularly if you live at the top of a hill and travel to the bottom of the valley.

It would be very exciting if it were ever breached as the operating pressure is never less than 60bar and usually 80-90bar.

A helicopter with a sniffer flies along it every fortnight.

I hope it's buried under several meters of cement.

Cloudy days are a noticeable problem.

Short days are even more of a problem.

Yup. We have So they will certainly be doing something

Yup, it is beginning to feel that way.

It breaks my heart, but I've advised my daughter to try to find a way to emigrate.

Correct. Residential premises don't use heat pumps running in either direction.

Yes it does go up in winter. You can see the last annual graph at

Scandalously, we have >> I'm also being told it will be a huge problem to provide enough charging

Insurmountable? No.

Very significant to the point of being impractical, yes.

Correct.

Not in my road, not in many roads.

Thanks, John. Nice to have advice from someone that actually knows what they're talking about for a change.

at. I do it when I drive to TN or back.

rules here are max 4.5hours then minimum 45 minute rest, max 9 hours total then a 11 hour rest

We have 30KW, 120-N-120 at 125 amps. We have gas too, so we use a tiny fraction of that capacity.

Car charging would be possible but very inconvenient.

Do you get many false trips?

Kerosene? Yikes.

I hate cooking on an electric range. Gas is great.

I thought you were referencing the situation specifically in the UK, where access to charging, even if you own your own home, is frequently impossible.

Instead of making ignorant, offensive remarks, take the guesswork out and check out the facts for once in your miserable life.