Snug Octopus (Economy 7) Problems

worlestone

Has anyone else here switched to Octopus Snug and having timing problems?

Apparently the smart signal can take a while to switch between peak/off peak.  Our switching is happening 10 minutes later than expected. This means we benefit from 50 minutes of off peak electricity, then the last 10 minutes of charging falls into peak rate. Not a concern overnight as the heaters have largely charged up, but for the afternoon hour boost the heaters are still charging, an extra 55/60p per day… it all adds up. 

For the last week the off peak 'boost' has been scheduled between 15:00 and 16:00, so ours switches at 15:10 and off again 16:10. Fortunately I'm at home a lot and can manually switch the off peak consumer unit off, but less than ideal.

Surely Octopus could compensate this by sending the switch signal ay 14:50 and 15:50.

I've also noticed that the 6 hours overnight is now spread between 23:00 and 06:30, some half hour slots being switched off...

QrizB

worlestone said:

Has anyone else here switched to Octopus Snug and having timing problems?
Apparently the smart signal can take a while to switch between peak/off peak.

This is a feature not a bug. E7 switching times are deliberately varied by up to 15 mins in each direction, to prevent every consumer being switched simultaneously and surge loading the distribution network. I would espect the same to appy to Snug.

For appliances switched by the meter ALCS, it makes little difference since the ALCS should switch at the same time as the tariff. It's only really a problem where you're using a standalone timer to try and match the off-peak hours.

Scot_39

worlestone said:

Has anyone else here switched to Octopus Snug and having timing problems?

Apparently the smart signal can take a while to switch between peak/off peak.  Our switching is happening 10 minutes later than expected. This means we benefit from 50 minutes of off peak electricity, then the last 10 minutes of charging falls into peak rate. Not a concern overnight as the heaters have largely charged up, but for the afternoon hour boost the heaters are still charging, an extra 55/60p per day… it all adds up. 

For the last week the off peak 'boost' has been scheduled between 15:00 and 16:00, so ours switches at 15:10 and off again 16:10. Fortunately I'm at home a lot and can manually switch the off peak consumer unit off, but less than ideal.

Surely Octopus could compensate this by sending the switch signal ay 14:50 and 15:50.

I've also noticed that the 6 hours overnight is now spread between 23:00 and 06:30, some half hour slots being switched off...

Not on snug - but interested in considering it in future.  If ever lose e10 - or decide tge 9p night worth risk of paying a bit more on day even on plugins.



This behaviour was expected and described in the FAQ as a definite possibility - and they say would vary by meter but not explicitly by meter type.


I am not sure it's description in the FAQ made it sound like the upto 15m configurable but certainly in past preset fixed per digital or analogue anti surge offset on standard regional e7 alcs meters timings.

Do you know if your meter offset was 10m before moving to snug ?

Mines is within minutes of other clocks - but I guess Octopus could reconfigure it if an option on smart.

But it's an interesting thought i hadnt considered.


From FAQ under at least 2 or 3 of the questions 

"It sometimes takes a bit of time for meters to react to smart charging, but most respond within 15 minutes. Any delay that does happen could cause some charging to happen at peak times, which means you'll be charged the day rate."



But I am being quoted 9p night 26p peak and your showing like 15p and 45 p on the blue  pricing line.

Have you checked the kWh vs the costs displayed.


And be interested to know what you requested I terms of charge profile.

As faq implies you can set a time target and a cap on total hrs off peak.

When I first looked at the snug pre launch page it contained a sentence that I cannot see any more which I didn't fully understand the implications of  and so asked for  clues / clarifications 

https://forums.moneysavingexpert.com/discussion/6569093/snug-octopus-new-tariff-for-older-meter-alcs-nsh-inc-1-hr-afternoon-winter-boost

"On sign up, you'll tell us how long you want the heaters to run and when you want your house to be warm, and we'll charge them at the cheapest, greenest times" 

We're you still asked to chose those when actually signed up ?

Looks like you have highish use in 11 if not 12 slots overnight - but the pre midnight is certainly an unexpected departure as is the extra hour - you have 14 green bars from 1130pm to 630am showing  (just).

I took that as being able to set a reduction on the 7 hrs or rather 6 hrs overnight window - and say if only wanted 2 hrs to be able to choose warmest at say 2:30am or 630 am - but it's not obvious if many with older heaters and a more standard sleep pattern would choose the earlier early am slot  time.

And then i wasn't sure if asked for say 3 hrs if that meant the ful 6 hrs wasn't thrn off peak.

Say if wanted snug for alcs hesting and an ev charger in future needing the longer block and probably I guess more fixed timing - unless drove an ev charger off of restricted as well if they can be wired that way.

Even in realky cold weather I don't think I've ever charged my nsh for the full 7 hrs limit on snug in winter let alone my e10 s 10 hrs  with time to discharge in between the 3 charges.

Ildhund

What type of meter is this? It probably doesn't matter, but SMETS2 mandates a built-in randomized delay in offpeak times:

5.7.5.28 Randomised Offset [INFO]

The product of the Randomised Offset Limit(5.7.4.33) and the Randomised Offset Number(5.7.1.5) rounded to the nearest second. This value is used to delay the Tariff Switching Table times and the Auxiliary Controller switching times.

I don't know how Octopus are implementing this new tariff (does anyone?), but if they are sending a command to change the ALCS calendar but leaving the ToU matrix as it is, the sort of discrepancy you're seeing might arise. The offset can in theory be up to 30 minutes ...

If the meter has separate registers for peak and offpeak consumption, you should be able to check whether the differences between readings for consecutive days tallies with the peak and offpeak usage data. 

Of course, what you're seeing may have a completely different cause.

worlestone

Our offset has been 10 minutes since Octopus fitted a Smart meter 4 years ago.  

I'd not noticed that the Octopus chart showed off peak at 15p! It is 9p/kWh on our agreement.

We haven't chosen our hours, but what has happened during the last week and a bit is that the off peak started off as 00:00 - 06:30 with charging across all the hours and has now changed to charging between 23:00 - 07:00, though there are half hour slots during this time when no charging takes place.

I think my concern with this is not the technicality of how or why it happens, but that Octopus have promoted Snug as having an off peak hour 'boost' in the afternoon.  But it's not, for us it's 50 minutes off peak which then rolls into 10 minutes at peak, so any saving is gone. An hour is 60 minutes after all, not 50

Scot_39

I took at as typically anywhere between 60 / 0 and 45/15 rates wise - possibly even worse.

And in theory the 15m could happen at the end of the night 6 hr session as well.

As when doing sums before a change - I tend to look for the problems - after years of testing complex engineering solutions.

QrizB

worlestone said:

But it's not, for us it's 50 minutes off peak which then rolls into 10 minutes at peak, so any saving is gone. An hour is 60 minutes after all, not 50

Do Octopus charge for Snug based on the 30-minute metering values (like they do Agile or Go) or do they use two registers in the meter (like they would for E7)?

If the latter, it makes no difference. You'll get the full 60 minutes at the cheaper rate.

Phones4Chris

That graph is VERY poor IMHO. The Half-hour pricing (blue) plot should not have a gradual rising/falling line, (leaving aside the 9/15p issue) after all the rate switches immediately it doesn't gradually change from 15 (or 9) p/kWh to 45p/kWh so the plot should be a "square-wave" in effect.
As pointed out by @QrizB are they charging the Snug tariff by the R1 & R2 registers?
Also look at which register is incrementing in the afternoon boost. Does it change from R2 to R1 during (towards the end/last 10 minutes of) the boost period?

@worlestone so as to be crystal clear about this, we need you to confirm that your smart meter is indeed a FIVE terminal where your off-peak is switched entirely by the meter ALCS.
Also for general clarity, on a normal E7 tariff the ToU (R1/R2) switching and ALCS switching should be at identical times - any difference means something hasn't been programmed correctly. I would hope this would be similar for the Snug tariff.
Going by the cost plot on that graph (hence kWh consumption) it suggests you are getting 90 minutes (3 x1/2hr buckets) of afternoon boost UNLESS your heater on timings are not fully controlled by the ALCS but some other timing device.
I'd also like to see the kWh plot because that graph also suggests there maybe more than 7hrs of "off-peak", there seem to be 16x 1/2hr off-peak (green) buckets! If it's a 5-terminal meter I do wonder exactly what the ALCS is doing!

Scot_39

I assumed Octopus would be using half hourly billing - as it is a requirement for the meter / tariff.

I also perhaps wrongly assumed that the ALCS might actually vary from the core 6 hours - but still not 100% sure the 9p would remain for 6 hours - if could - as the how long and when ?s  implied - say to reduce charge times to say last 2 or 3 hours of window.

I thought that the ALCS table would at most if used be updated daily - and as the OPs appear to be switcing with the same 10m delay - assume the QRizB answer probably explains it.

But had wondered if the "react to .... respond" wording meant they were actually doing something even more dynamic - an actual open / close contact - OTA message - but then dismissed thinking that could screw up royally if lost signal for hours / days etc.

IIRC the HAN spec allows for messages for several external switches - not sure if WAN messages do - I found a long list of them years ago - must search again.

worlestone

@Phones4Chris our meter is as photo below, as far as we're aware (told by Octopus) the switch triggers the off-peak/peak switch for whole of house though two separate consumer units, one with immersion + storage heaters and one for everything else.

@Scot_39 I don't understand much of what you've written, I'm not familiar with the acroynms! I've just had an email from Octopus saying they would change my off peak times to 00:30 to 06:30 as Snug should be, but nothing about the 10 mins offset.  The only way I can deal with that at the moment is turning the off-peak consumer unit between 16:00 - 16:10 to stop the storage heaters from charging at peak rate.  I'll have another go at asking Octopus if they can change this after the Christmas break.

Scot_39

Phones4Chris said:

@worlestone so as to be crystal clear about this, we need you to confirm that your smart meter is indeed a FIVE terminal where your off-peak is switched entirely by the meter ALCS.

Or as in the OP's case a 4 port meter with a 2A (max) ALCS control signal output and an external contactor.

The preferred solution of some suppliers - including EOn at the time of my last upgrade. (They actually replaced a 5 port digital with 4 port smart and Proteus 100A block - so meter cabinet isolator switches etc had to be moved on back board)

It's still fully meter controlled.