Is the "Smart" meter role out being done ready for another Winter of discontent.

[ericmark]

In 1978 with the last Winter of Discontent the electrical power was switched off at set times to conserve energy, OK for those with coal and gas fires, but those with only central heating even if it did use gas or oil, it would not run, we had a cold winter, and we fitted a flue less gas fire and vowed we would never again have a home which relied on electric as only form of heating.

Today many people live at home where back in 1978 they would have needed to be in hospital, we have devices which can keep people alive at home, their homes are on a register so energy companies know they must not be switched off, which would mean the repeat of 1978 power cuts can't be done now, however smart electric meters have a relay so the supplier can disconnect the home, so they can select who they disconnect, has this been done so people can be switched off but leave the vulnerable connected. I see no other use for the relay which the energy companies say they will not use. But the government has given no such reassurance.

Glad I have not got a Smart Meter.

 

[AdrianUK]

I do remember the Winter of Discontent 1978/9 and the previous one with the strike of 1973/4 leading to the 3 day working week - although I was at school for both of these so didn't mind the extra holiday

I know that there are registers of vulnerable persons but I'm not sure that would mean they won't be disconnected if "rolling Blackouts" happen this winter. I suspect the disconnection would be at the 11kV or higher level & probably remotely via SCADA. I don't see that it would be selectively pulling 400V fuses at the local substation. If the decision is taken not to disconnect any 33 or 11kV circuit with a vulnerable person on it I don't think there would be many circuits that could be switched!

Our world is very different today than in 1978. We have been starting to plan for how we might cope in our small (~100 people) factory if scheduled power cuts were to happen this Winter - its starting to make my head hurt! Obviously we would have to close on those days that we don't have power. The space heating is by gas but it does rely on an electrical control system so there would be no heating. The factory hasn't been 'black started' for at least 5 years. I'm not sure what would happen if we attempted it. I'm quite sure that if the place wasn't shut down properly the start-up surges as everything tries to re-power would be popping breakers out all over the place.

Obviously the fire-alarm & intruder alarms would ride thru a 4/5/6 hrs power cut with no issues, but the UPS's supporting our Servers would not. Nor would the ones supporting our networking switches etc. Most UPS systems are only intended to hold up for long enough to allow a graceful shutdown of systems - 20-30 min at the most - the wont deliver for 6 hrs. In any case the server room aircon will have shutdown so the servers need to shut off to stop the heat production.

 

[JohnW2]

I know that there are registers of vulnerable persons but I'm not sure that would mean they won't be disconnected if "rolling Blackouts" happen this winter. I suspect the disconnection would be at the 11kV or higher level & probably remotely via SCADA. I don't see that it would be selectively pulling 400V fuses at the local substation. If the decision is taken not to disconnect any 33 or 11kV circuit with a vulnerable person on it I don't think there would be many circuits that could be switched!

You're talking there about the 'old' system, whereby all they could do was to switch of bits of the HV network (and probably not even bits of the LV distribution.

However, eric's point was surely that 'smart' meters theoretically creates the opportunity for supplies to effect switching off of individual consumers at the level of their meter - which presumably, if done, would enable the (obviously automated) process of transmitting instructions to countless 'smart' meters to 'switch off' could easily be programmed to exclude meters of those customers on a 'vulnerable register'.

That would obviously be of benefit to the vulnerable people, but I don't see why this should be of any concern (or even 'interest') to anyone else - if they lose their electricity because of a deliberate 'switch off', it makes no difference to them whether the switching was done by a relay/contactor in their meter or by a much bigger bit of kit interrupting an 11 kV (or whatever) feed.

Kind Regards, John

 

[AdrianUK]

But is the penetration of smart meters deep enough to make that actually work? I agree that, in theory, it would be possible to turn off the output of a smart meter at will (do they all have switches? I'm not sure they do) but would it reduce demand by "enough"? If not, then we would be back to higher level switching at the HV level.

 

[JohnW2]

But is the penetration of smart meters deep enough to make that actually work?

I presume that the comments are 'forward looking' - looking to the time (which will presumably come) when 'smart' meters are pretty universal - either literally or effectively 'compulsory' (the later being that suppliers won't offer supplies to people who aren't prepared to have a 'smart' meter).

Having said that, even at December 2021, some 26 million 'smart' meters had been installed (nearly all in domestic installations), so the 'penetration' is already very high (there are only about 28 million 'domestic households' in UK)

I agree that, in theory, it would be possible to turn off the output of a smart meter at will (do they all have switches? I'm not sure they do) ....

I may be wrong, but I think the specification of SMETS2 meters requires that they have 'switches' - even though suppliers appear to have 'promised' not to use them (at least for people who don't pay their bills0.

but would it reduce demand by "enough"? If not, then we would be back to higher level switching at the HV level.

... as above, deployment of 'smart' meters appears to be already very high but, if not now, then presumably 'eventually'.

Kind Regards, John

 

[MeldrewsMate]

In recent months I've read many interesting articles revolving around renewables' generation. The last one (Dogger Bank) was of a new offshore wind turbine plant claimed to be capable of generating (from memory) 3.6 GW. It was quoted as being enough to power 5 million homes.
A quick calculation therefore, revealed that '1 home' consumes about 720 W on average. Surely this is a misleading figure. This is of course the average, but it's only about 1/3 of the power my kettle consumes, so for a couple of minutes I'll be using 2 neighbours' allowance each time I make a brew...and vice versa.
If I plug my 40kWhr electric car in for an overnight charge at 5 kW I'll be using 6 neighbours' power allowance for 8 hours, and if my modest 8 kW air source heat pump is on all day this winter (and all night if the weather gets cold and it's CoP drops below 3) I'll be taking another 10 neighbours' power....
...and I won't be the only one in my street with a kettle, an electric car (or two!!), and an ASHP.

So in essence I'm going to use up about 16 times as much electricity overnight as I should and, I assume, the power distributors deem normal. Now if my neighbours also want to squander power in the same way, those teensie weensie distribution cables in my street might run a little hot....if they run hot there'll be a high risk of a cable going pop, and all of my street losing power. Leaving aside the inconvenience of waking up to a cold house with a car that won't get me to work, and with no power to 'work from home', I and my neighbours will be stuffed.
I'm sure the distribution network will get sick of popping cables and react 'to protect the network' by selectively shutting off smarty-pants meters down my street.
Think about that future, it's certainly disfunctional, but on present performance it's unavoidable. I have some predictions for the future, Nostradamous take note

1. You won't be allowed to have a car charging point unless you have a smarty-pants meter.
2. Building Regs will be changed to insist on all new buildings having 40% or more of the roof facing south. (A truly sensible idea...one of mine!)
3. Regulations will be introduced to allow distribution network operators to limit the total amount of electricity a household may consume, with a sliding scale of charges as consumption approaches this household maximum target.

Come back in 5 years to see how I did.
MM

 

[JohnW2]

A quick calculation therefore, revealed that '1 home' consumes about 720 W on average. Surely this is a misleading figure. This is of course the average, but it's only about 1/3 of the power my kettle consumes, so for a couple of minutes I'll be using 2 neighbours' allowance each time I make a brew...and vice versa.

I think you probably need to gain a better understanding of what 'averages' are all about.

What you say above is arithmetically true, but only for two minutes. If you boiled your kettle just once per day (for 2 mins), then assuming it was a 2,000 W kettle, the kettle's average power consumption would only be about 2.8 W. Even if you boiled it 10 times per day (each for 2 mins), its average consumption would only be about 28 W - still a very small proportion of a household's total daily consumption.

If I plug my 40kWhr electric car in for an overnight charge at 5 kW I'll be using 6 neighbours' power allowance for 8 hours, and if my modest 8 kW air source heat pump is on all day this winter (and all night if the weather gets cold and it's CoP drops below 3) I'll be taking another 10 neighbours' power.... ...and I won't be the only one in my street with a kettle, an electric car (or two!!), and an ASHP.

One now has to look at averages across houses as well, and not just over time. In the case of the kettle, the chances of hundreds, thousand or millions of households boiling their kettles during exactly the same 2 minutes is incredibly small and, in practice, it would largely 'even out' - so that, over a whole day, the average over N households would be close to N times the (very small) average consumption/day/household.

The EV charging and heat pumps are (will be) a different matter, since when both are in very widespread use, the average consumption per household (over a period such as 24h) will become much more than the present 720 W - so the sums will change a lot. However, at present, both EV charging and (even more so) heat pumps are so relatively uncommon that the average electricity consumption ()across households) has not (yet) increased very much.

So in essence I'm going to use up about 16 times as much electricity overnight as I should and, I assume, the power distributors deem normal. Now if my neighbours also want to squander power in the same way, those teensie weensie distribution cables in my street might run a little hot....if they run hot there'll be a high risk of a cable going pop, and all of my street losing power.

Yep, one of the major issues is that the current distribution network is not going to be able to cope with widespread deployment of EV charging and heat pumps. As above, there are not yet enough of either for this to have yet become a significant problem, but it certain will eventually, so that some major upgrading of the supply network will eventually become necessary.

Kind Regards, John

 

[ericmark]

I have been debating buying a small inverter generator and swapping the FCU on boiler to plug and socket, so in a power cut I will still have heating. I do have a small inverter battery pack not sure if large enough for boiler, and a fire place, never lit a fire in it, maybe I should get the chimney swept?

Due to an industrial injury I can't stand cold weather, we have a stand-by oil filled radiator in case boiler fails, but getting out the chainsaw to keep warm is not my idea of fun, and clearly any wood not already cut will be too green to burn.

The one remaining coal mine in Wales the washing plant has failed, so all coal sold direct to steel works. I have seen the problems with compressed coal dust fuel in the boilers at work, the ash, well not really ash, more like un-burnt coal dust gets everywhere, the guards need to sweep the carriages out every run, really don't what that in my house.

So is it one of these at the ready? It depends on how likely we are to loose power.

 

[winston1]

In the case of the kettle, the chances of hundreds, thousand or millions of households boiling their kettles during exactly the same 2 minutes is incredibly small and, in practice, it would largely 'even out' -

It happens, usually at the start of an ad break in a popular TV programme.

 

[bernardgreen]

What you say above is arithmetically true, but only for two minutes. If you boiled your kettle just once per day (for 2 mins), then assuming it was a 2,000 W kettle, the kettle's average power consumption would only be about 2.8 W.

But if everybody switched their kettles on at the same time the load for those 2 or 3 minutes could exceed the output from the generation.

When TV programs had an advert break people put kettles on resulting in an increased demand and a drop in voltage and frequency as the generators took up the extra load.

EDIT I hadn't seen Winston1's post

 

[AdrianUK]

But if everybody switched their kettles on at the same time the load for those 2 or 3 minutes could exceed the output from the generation.

When TV programs had an advert break people put kettles on resulting in an increased demand and a drop in voltage and frequency as the generators took up the extra load.

EDIT I hadn't seen Winston1's post

Yes it does, but it needs to be (and is - since the TV schedules are known) planned for.

As demand starts to exceed generation then the frequency begins to fall as the kinetic energy stored in the rotating generators is converted at a rate greater than it is replenished. If steps are not taken PDQ to bring extra generation online (which is why we have 'spinning reserve' in the system) restoring the balance then automatic load-shedding will happen to protect the system. Once this starts it tends to be a chain reaction which can be hard to stop - the system can yo-yo between too much & too little generation as load may be removed in bigger lumps than the excess. Recovery from this situation can take many hours - especially if generation has been shut down quickly without proper slow down/cool down.

('Spinning Reserve' are generators which are running upto speed & synchronized onto the grid but not actually producing any real power. They may well be producing reactive power & thus providing voltage support but they are not providing any Watts into the system. When they are required, its a quick matter to further open the steam valves and start to actually produce real power. the process takes seconds instead of the hours that it would take if the generators were not already spinning. Note that the trend towards renewables is making this problem worse - inverters don't have any rotating mass & cant store kinetic energy - they have no ability to help ride-thru small short duration power demands unlike their coal or nuclear brothers & sisters.)

 

[ericmark]

Your account of the rotating mass is good, and is one of the problems where the generation is through inverters, be it wind or solar the inverter synchronises not the rotating mass. And even as the gas valves are opened with the combined power like at Connah's Quay there is a delay before you get steam, I seem to remember when I worked there around 24 hours to heat up/cool down. We do have the Electric Mountain "Dinorwig Power Station" but very few generators can come on line that fast, and to protect workers micro generation is set so if frequency is not 50 Hz or the voltage is above 253 or under 207 they auto shut down, so you get the domino effect.

It was to be frank some thing I missed, switching off areas of power will also switch off micro generation, so even more reason to do it home by home.

The EV charging will likely help as this can be switched off remotely but leave the home with power, but what proportion of EV charging point have the remote control I don't know?

I visited daughter and noted the EV charging point next door, but was told they no longer have an electric car, that was also some thing I did not consider, with the main reason for the electric car take up being the tax breaks one gets with it, especially when a company car, changing ones job can mean you no longer have the electric car. So unless the DNO tests an area then no idea on how much they can save turning off EV charging points.

 

[JohnW2]

It happens, usually at the start of an ad break in a popular TV programme.

But if everybody switched their kettles on at the same time the load for those 2 or 3 minutes could exceed the output from the generation. ... When TV programs had an advert break people put kettles on resulting in an increased demand and a drop in voltage and frequency as the generators took up the extra load.

Needless to say, I expected that one, but didn't have time to anticipate it in what I wrote yesterday!

All the above is true, but the OP was talking about average loads (over time), which will be the same whether the kettles are all on simultaneously or nicely spread out over time.

However, it is obviously in the nature of averages that they do not in any way preclude the possibility of very high peaks (or very low dips) in instantaneous demand. That usually does not happen to a problematic extent (things tend to 'even out') but it certainly can, in situations such as you both mention. The producers of electricity are well aware of this, and therefore do everything they can to anticipate and 'cope with such instantaneous peaks in demand, as has been said ....

Yes it does, but it needs to be (and is - since the TV schedules are known) planned for. ......

There is, of course, a limit to their ability to service a very high instantaneous demand (even if it can be anticipated) but I haven't yet heard of any cases in which they have 'failed' to the extent that, say, a Coronation Street break or half-time in a cup final has resulted in the need for power cuts - but it theoretically could happen, increasingly more likely if demand (particular due to EV charging and heat pumps) rises more rapidly than supply capacity..

Kind Regards, John

 

[ericmark]

We have reports of the problems with the moving of power where the decentralisation of generation is causing problems. In the early days of micro generation it reduced the load in an area, but there was no real transfer area to area of micro generated power.

I know when working on the building of Sizewell 'B' there was a problem with the voltage difference when the 'A' station was on line or not, with 260 volt at some times being recorded. And never before had I seen auto transformers used for imported plant from the rest of EU, it was set to reduce voltage from 240 to 220, but at the time we should have all been at 230 volt.

There must be a volt drop and can't see how we can transmit power bi-directional without having two net works at low voltage, the supply and using, I did see in North Wales the voltage drop from 245 to 230 as solar panels were fitted, but simple maths, 100 amp must cause a volt drop, at 0.35Ω looking at 35 volt 253 - 207 = 46 volt to work both ways needs to be no more than 23 volt, so max is 0.23Ω and that with no volt drop on HV supply, it is simple maths, we seem to have reached the limit for micro generation unless we use different step up and step down transformers.

 

[JohnW2]

.... , but simple maths, 100 amp must cause a volt drop, at 0.35Ω looking at 35 volt 253 - 207 = 46 volt to work both ways needs to be no more than 23 volt, so max is 0.23Ω and that with no volt drop on HV supply, it is simple maths, we seem to have reached the limit for micro generation unless we use different step up and step down transformers.

I need to think fairly deeply about that 'simple maths" - but if I succeed, I may have something to say

Without that necessary thought, my first intuitive reaction was that the 'export VD' ought to reduce (maybe even 'cancel') the import VD' - but that may well be all wrong!!

Kind Regards, John