immersion Heater mystery? (Ed.)

JohnW2 · 14 Feb 2025

JohnD said:
The wholesale price is set dynamically, by bid and offer, it's much much less than the punters pay. It used to be published in half hour lots, I don't know a source for it now. .... The nighttime demand is low, so every extra pounds worth they can sell is an extra pound towards the CEO's next yacht. ...

Yes, I obviously understand why nighttime electricity is cheaper, and why it'sin the supplier's commercial interests to sell as much of it as they can.

What I find much less easy to understand is why they seem to be offering much cheaper nighttime electricity specifically 'for EV charging' but not if it is wanted for other purposes - do they simply see (hope) that by so doing they will attract a lot more customers with appreciable night-time usage,or what?

Harry Bloomfield · 14 Feb 2025

ericmark said:
What have you got to test with? An immersion heater can take hours to heat the tank, even a pen tester,

can help, you know power to cable in seconds rather than hours, I don't like pen testers so not saying rush out and buy one, but give us an idea what you have to test with.

You can usually hear, when an immersion heater is on, just as you can when a kettle is turned on.

ericmark · 14 Feb 2025

Harry Bloomfield said:
You can usually hear, when an immersion heater is on, just as you can when a kettle is turned on.

If you say so, since mine uses variable power, the only way I know it is on, is what the display says. It will say 200 watt etc.

But if you can tell if bottom or top immersion working from the noise, then fair enough. The tester my wife got me does do more,

however, there is no point trying to work out what is going on, if you have to wait for the tank to get warm. Also, an idea of how it should work, there must be at least 50 immersion heater timers,

some for dual supplies and some for a single supply, with boost buttons etc, and to work out which is being used requires some feed back.

Yes the tariffs have changed, I have an EV tariff, with by the way no EV, and I have 8.95p per kWh for 5 hours, and 31.31p for the rest, it was 29.57p per kWh when on a single tariff. The £1.74 extra during the day is nothing when you look at the ratio peak to off-peak,

it is clear I am gaining using off-peak.

But that is not the question, @amosbrown1 wants hot water, as to cost, and well, that is of secondary importance, we get use to the idea of using a meter, my little meter

does so much in one little package, including non-contact AC volts, and AC and DC amps, but without some tools, it is going to be hard.

Harry Bloomfield · 14 Feb 2025

ericmark said:
If you say so, since mine uses variable power, the only way I know it is on, is what the display says. It will say 200 watt etc.

I would not expect to hear 200w, but 3Kw, produces noisy 'micro-bubbles' at the elements, after a few second of being on, and quite noisy.

Harry Bloomfield · 14 Feb 2025

JohnW2 said:
What I find much less easy to understand is why they seem to be offering much cheaper nighttime electricity specifically 'for EV charging' but not if it is wanted for other purposes - do they simply see (hope) that by so doing they will attract a lot more customers with appreciable night-time usage,or what?

They try hard, to make sure there is no surplus wasted energy, it costs big money to run plant up to speed, and to close it back down. Octopus, offer next day incentives to reduce consumption, when demand is high, and offer free power when demand is low, to attempt to balance out demand. So far as the EV charging goes, I understand it is the one thing, the supplier can directly control, to turn it on and off, when it suits them - unlike domestic off-peak heating.

JohnW2 · 14 Feb 2025

Harry Bloomfield said:
They try hard, to make sure there is no surplus wasted energy, it costs big money to run plant up to speed, and to close it back down. Octopus, offer next day incentives to reduce consumption, when demand is high, and offer free power when demand is low, to attempt to balance out demand.

Sure, I understand all that, but my question remains - why do they want gto 'incentivise' those who have EV chargers, but seemingly not others, to use electricity when demand is currently low? However, you go on to say ....

Harry Bloomfield said:
So far as the EV charging goes, I understand it is the one thing, the supplier can directly control, to turn it on and off, when it suits them

Is that true? How?

Harry Bloomfield · 14 Feb 2025

JohnW2 said:
Is that true? How?

I don't know much about it, but I understand suppliers can 'talk' to the meter, the meter can 'talk' to the charger. The EV can even back feed the network, to help with the peaks.

JohnW2 · 14 Feb 2025

Harry Bloomfield said:
I don't know much about it, but I understand suppliers can 'talk' to the meter, the meter can 'talk' to the charger. The EV can even back feed the network, to help with the peaks.

The supplier can certainly 'talk to the meter' (as well as vice versa) and the ultimate plan is that the meter will then be able to talk to 'smart appliances' (very few of which yet even exist) and so 'interfere' extensively with when one can and cannot use all of ones appliances - but I doubt that is going to happen in my lifetime

Maybe some EV chargers are already 'smart' in that way but, if so, I didn't realise that.

AndyPRK · 14 Feb 2025

I believe all (big/30A+) chargers must have an internet connection, so that the load can be switched off to protect or ballance the grid (or maybe select the starting time). I think they have a random start time built in.

This maybe one reason why some tarriffs/companies prefer EVs to storage heaters

Murdochcat · 14 Feb 2025

JohnW2 said:
The supplier can certainly 'talk to the meter' (as well as vice versa) and the ultimate plan is that the meter will then be able to talk to 'smart appliances' (very few of which yet even exist) and so 'interfere' extensively with when one can and cannot use all of ones appliances - but I doubt that is going to happen in my lifetime Maybe some EV chargers are already 'smart' in that way but, if so, I didn't realise that.

Suppliers can’t legally remotely turn off your power, so they can’t control when your EV is charging or not, or your dishwasher etc

JohnW2 · 14 Feb 2025

Murdochcat said:
Suppliers can’t legally remotely turn off your power, so they can’t control when your EV is charging or not, or your dishwasher etc

I think they probably can, if you sign a contract (in order to get the cheap tariff) that says that they can. As I said, this 'smart control of smart appliances' is what smart meters are (ultimately) all about - but I don't think you'll be around to see much of that happening, any more than I will!

JohnW2 · 14 Feb 2025

AndyPRK said:
I believe all (big/30A+) chargers must have an internet connection, so that the load can be switched off to protect or ballance the grid (or maybe select the starting time). I think they have a random start time built in. This maybe one reason why some tarriffs/companies prefer EVs to storage heaters

Yes, maybe and maybe - I really don't know.

Murdochcat · 14 Feb 2025

JohnW2 said:
I think they probably can, if you sign a contract (in order to get the cheap tariff) that says that they can. As I said, this 'smart control of smart appliances' is what smart meters are (ultimately) all about - but I don't think you'll be around to see much of that happening, any more than I will!

Smart meters are all about charging variable rates for lecky. Nothing more, nothing less

JohnW2 · 14 Feb 2025

Murdochcat said:
Smart meters are all about charging variable rates for lecky. Nothing more, nothing less

At present, that's all they can be used for. Once 'smart appliances' become more available and our widely deployed, it's going to be a very different world - but, as I said, I doubt that either of us will see it!

JohnD · 14 Feb 2025

JohnW2 said:
Yes, I obviously understand why nighttime electricity is cheaper, and why it'sin the supplier's commercial interests to sell as much of it as they can.

What I find much less easy to understand is why they seem to be offering much cheaper nighttime electricity specifically 'for EV charging' but not if it is wanted for other purposes - do they simply see (hope) that by so doing they will attract a lot more customers with appreciable night-time usage,or what?

The EV owners may buy quite a lot, making a profitable segment of the market.

If the other mugs are willing to pay high prices for low cost nighttime electricity, the power companies will not stand in their way. They have no choice but to buy it.

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immersion Heater mystery? (Ed.)

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