Changing Economy 7 times

NFH

I have an Economy 7 meter, which is radio controlled with fixed hours of 23:30 GMT to 06:30 GMT (00:30 BST to 07:30 BST). These fixed times are marked on the meter and I do not have a separate Economy 7 circuit; my hot water is heated on a timer.

According to NPower (not my supplier), the Economy 7 cheap rate period can fall between 22:00 and 08:30, depending on time of year and region. I am in London, which NPower says falls between 23:00 and 07:00. Given that mine ends at 07:30 BST, I assume that the times stated by NPower are in GMT.

I would like to change my Economy 7 times to 00:30 GMT to 07:30 GMT (01:30 BST to 08:30 BST) so that my hot water continues to be heated while I am using it first thing in the morning, which will leave more hot water remaining in the evening. Is this possible, and if so, how?

Cardew

No - not possible.

NFH

Cardew wrote: »

No - not possible.

Can you elaborate please?

matelodave

E7 times are usually controlled by the generation company and not the supplier so you have to try and work around those times.


If yours are radio controller rather than timer controlled then there is always the possibility that they might change within the specified window so that the generator can optimise his power profile.


You should make sure that your timers are set well within the window of operation otherwise you could end up with half an hour or so of peak rate if you aren't careful.

NFH

matelodave wrote: »

If yours are radio controller rather than timer controlled then there is always the possibility that they might change within the specified window so that the generator can optimise his power profile.

In that case, why are the times marked on the radio controller? I've checked many times, and the times are always accurate to within 30 seconds.

footyguy

Post removed ... :cool:

NFH

footyguy wrote: »

So unless you can find an illegal transmitter that can hack your meter, it's not possibible.

Taking into account that the meter goes on to cheap tariff at fixed times, which of the following applies?

1. The meter listens to the time transmission and changes the tariff at 06:30 GMT and 23:30 GMT (in which case the meter could be reprogrammed for another time).
2. The meter listens for an instruction from a central controller to change tariff, and the central controller is programmed to send this signal at 06:30 GMT and 23:30 GMT (in which case it must be possible to change the meter to listen to a different instruction given that the times vary from one customer to another).

How exactly does this work? No guessing please.

molerat

From the IET forums

Economy 7 switching signals are sent to dual rate meters over the radio 4 long wave carrier - a low data rate phase modulation is 'hidden' under the normal AM speech signal. This transmits coded time information every minute and also proprietery "meter switching" data blocks for different DNOs teleswitches and meters.
Thus a modern E7 time switch is going to work anywhere you can receive radio 4 (and a few places you cant - the data rate is low enough that quite a poor signal to noise ratio can be accepted).

and
https://en.wikipedia.org/wiki/Droitwich_Transmitting_Station

So to change it I suspect you would need to commit a criminal offence and break into the metering equipment.

NFH

So it could be scenario 1 (using time transmitted every minute) or scenario 2 (proprietary meter switching data blocks). How does either of these preclude a change to my switching time?

Bark01

The time pattern is set by your local meter operator not your supplier. Each meter has an SSC (Standard Settlement code). The SSC defines your time pattern. It is not possible to change an SSC without replacing your meter and even then you can not pick and choose what times you get or what SSC you get, you'll likely get the same one.

Energy Suppliers will gave the ability to bypass the current restrictions in the SMART world, but I think allowing personalised time patterns is a long way off.

thozza

Try these for more information:

https://www.ofgem.gov.uk/ofgem-publications/82288/state-market-customers-dynamically-teleswitched-meters.pdf

https://www.elexon.co.uk/wp-content/uploads/2012/07/PSRG22_01_dynamic_switching_roadmap.pdf

Key parts from the 2nd would appear to be

2.3 Both clock switched and teleswitched meters can support a static regime (i.e. where the registers are switched at the same time every day of the year) or semi-static (i.e. where the registers are switched at the same time every day within a defined season). Teleswitched meters can also be switched dynamically. For example, some night storage heaters are controlled dynamically to take into account prevailing or forecast weather. Suppliers are responsible for determining register switching times and communicating them to the RTS Access Provider for onward transmission to Metering Systems via the administrator of the switching infrastructure (the role fulfilled by the ENA).

2.4 Teleswitch commands can be programmed (i.e. issued in advance) or immediate – i.e. to shed/boost load quickly (e.g. in the event of loss of generation or periods of high demand). The latter is currently used sparingly, and creates issues for profiling accuracy in terms of determining whether a Settlement Period in which load shedding occurred should be treated as “on” or “off”.

Which seems to suggest that for the OP with a teleswitch there are a number of possible operating modes dependent on the supplier and the meter, as to whether it is possible to have the times changed, it appears that this would be only be possible if the supplier organised it.