energy in UK

At the moment lithium batteries are collections of quite small cells - roughly D-cell size.

A tiny dendrite puncturing a separator may start an ignition wave that can propagate at centimeters per second, but only inside that D-cell - and that would take a badly designed separator.

This sounds more like journalistic alarmism than any kind of peer-reviewed study.

South Australia has had a grid scale battery for years and now has several of them. They haven't caught on fire yet. A grid scale battery in another state did catch on fire during construction, but mechanical damage seems to have been the root cause, and the fire was pretty localised - confined to one refrigerator sized block of cells. the batter got built anyway.

In the UK a lot of large domestic batteries use lithium iron phosphate which is much less likely to produce a spectacular fire than lithium ion. The individual cells are the size of a large brick.

For example:

Is there some time-averaging provision for high start-up transients, such as motors would need?

Is the metering based on wattage or current?

The current draw of a multiple lighting installation in a shop may be capacitive or the motors in a small workshop would be inductive and this would determine the size of cables needed, so current-based netering would make sense for that purpose. The current wouldn't be representative of the energy used, so wattage-based metering would make sense for energy-consumption billing purposes.

ISTR Italy and to some extent Japan have similar rules. When I lived in Japan only the aircon had a really juicy 240v supply. The domestic ring main 100v could not support for example a 3kW kettle. They had special slow electric kettles come thermos flasks to have boiling water on tap.

You also had to be careful not to run the aircon at full pelt and the washing machine at the same time or the circuit breaker would trip.

In the UK it is done by size of fuse into the home. You can overload the circuit a fair bit without blowing the fuse but it is expensive if you do since the electricity company has to come out and do the bonded repair. There are lead seals on the fuse connecting to incoming mains.

A few homes last rewired in the 1950's are still on 40A, most are on 60A or now 100A circuits. You pay for what you use. A few tariffs have a higher price for going beyond a certain amount for high use premises.

Local mains supply here had to be reinforced a couple of years back to support then PM Rishi Sunak's luxury heated swimming pool (he paid for the network upgrade himself). Wife is fabulously rich.

Traditional way in the UK is a copper nail through the cables on the wrong side of the meter. A method beloved of illegal cannabis farms.

Those individuals "cells" are almost certainly batteries of smaller cells, assembled into a neat rectangular package to ease the construction of large batteries. This is where on of John Larkin's X-ray machines would be useful. A hacksaw could be as informative, but it could get messy.

It depends a lot on the chemistry. The previous generation of NiCoMn Lithium cells were extremely volatile if they get damaged although have higher energy density. The latest generation of Iron based ones in the BYD blade implementation seem to be a lot more forgiving. This isn't a bad demo of the differences (bear in mind they are a battery vendor):

Moves are afoot to double the energy density in the next generation if they can overcome the tricky problem of metallic dendrite growth under certain charging conditions.

Only in toys and a few older cars. You are hopelessly out of date. Prismatic or latest blade cells are now in vogue for new build.

They do tend to go completely until it encounters an effective fire break. The jets of directed intense flame are something of a problem. Particularly in car collisions (tendency to relight also an issue) and vehicle recovery companies are unwilling to remove such fire damaged electric vehicles because of the risk of reignition.

The propagation between adjacent containers is predicated on windspeed less than 12mph and 6m spacing which is highly unlikely in the UK. They usually go for 3m here with pairs passive surface back to back.

The one I'm fighting is in a region with mean windspeed ~20mph and they want to use a 2m spacing based on some "interesting" fire risk analysis. UK land prices mean they want it as compact as possible.

Fire fighting plan consists of stand well back and let it burn. There is no water supply on site (actually there is - well pumped water on a 3" pipe 2 miles long). Fire code calls for multiple 0.6m fire hydrants.

You obviously missed the Victorian Big Battery fire using Tesla modules where during installation they burnt out two full containers worth (infant mortality on precharge due to a coolant leak). Safety systems that fail dangerous are not good. I suspect rough handling poor installation practices were to blame as root cause.

The choices the members were given were between a vastly pared-down selection of possible candidates: a short short-list decided by Tory MPs. If the members had had the choice of picking *any* MP they wished, I'm certain the result would have been completely different.

The major flaw in our current model of democracy as thing stand is the 'career politician' - who 30 or 40 years ago may have got into politics for the noblest of reasons, but has since had their principles completely compromised and has amassed considerable wealth from selling their influence to the highest bidder. We need to make the 'career politician' an historical curiosity.

I know that the classical motor in a fridge has a device, I don't know its name, that thermally triggers if the motor demands an unusual high current for some seconds, like when starting under load. It then keeps the motor off for a long time (minutes?), while the compressed gas leaks into the circuit, the pressure drops, and then the motor tries again.

Surely a modern fridge or AC unit with inverter knows how to cope with the situation.

I wonder how they are going to power those smart meters. Batteries? The water runs a generator that charges a battery?

With the electricity meter, I can browse to a page at the electricity company that shows a table or a graph of electricity usage per month or maybe a shorter period. We can see down to the usage per hour, I think. I suppose the water meter will do something similar, so that I can look by myself the water flow at 3 AM. If the meter has a leak detector, it should show in that web page.

Yeah, but I hope they tell us. I have not experienced this, but I suspect so.

Happened to my parents. They didn't bother, and put the new pipe above the floor, attached to the wall. Mostly behind the sitting room furniture, so visitors do not see it :-D

When the pipe arrives at the kitchen, it goes again under the floor tiles. I had to renovate the kitchen, I suspected slow leaks, and the pipe was indeed corroded. I replaced iron with some plastic.

Oh, it is indeed significant, can be higher than actual usage.

Doesn't fit the only politician I know all that well. His principles still seem to be in fine shape - he was a minister for a few years, and while his career may have suffered from his unwillingness to do the wrong thing, he did pretty well.

We bought the book he wrote before he became a minister, and when it got damaged in a domestic disaster I was afraid that it was going to be hard to replace, but the local bookshop had plenty of copies - it was a set text in a Cambridge University course.

If you do not limit your usage, some switch goes off, and the entire house is down. You learn to control what appliances you connect simultaneously.

An old granny can call her son or an electrician, but probably doesn't need to because the installation has decades of use and the calculation was done decades ago.

Yes. The trigger is slow.

Before smart meters, it was certainly current, a slow switch triggered by heat or a magnetic field. With smart meters I don't actually know.

The meters measure watts.

I suppose current smart meters can also measure the power factor.

Yes, same here.

I don't know if smart meters can sense that :-?

I expect they could easily do both - but I would be worried about which one was used to calculate my bill.

The meter that I designed noted the neutral current imbalance, which at least catches one cheating mode. No meter can tell if people are stealing power from the pole out on the street, except to note net power.

In New York city it was common for building owners to punch through a wall to tap into a neighbor's power wires. It wasn't unusual to find that being done in both directions.

Civilization runs on energy, and there is a powerful faction that wants to both control and cut off our energy.

Some want the power, and some are fundamentally anti-human.

Really.

The "US style two phase and neutral" is not actually two phases (at 90 degrees), it's single phase from a center-tapped transformer, with the center tap grounded to neutral (white wire in US). This is not the safety ground (green wire in US).

If I understand, Australia uses a corner-neutral 3-wire 3-phase distribution system, at least in rural areas.

Yes. There are two reasons. The first is of course to reduce the electric bill. But far more important is to prevent detection by looking for unusually high electric bills.

Ammonium Nitrate fertilizer sales are monitored for a similar reason.

Joe Gwinn

Yes. It is exactly the same as you describe in my village single phase centre tapped. Referred to here as two phase. Three phase is the norm.

We have two anti-phase mains supplies that have been transformed down from a transformer that spans A-B live phases on an ABC delta. Next village along will be on B-C and then C-A in a cyclic pattern.

These days they find them by drone thermal imaging.

We had other reasons to monitor it carefully. Bulk ANFO is a powerful explosive if you have a stick of dynamite and a detonator.