Here I go again ….

Swipe

@vienna28 Does your IHD show the off peak tariff rate cost when it is active?

QrizB

Let's work out the cost.

We've got Snug at 9p/kWh off-peak and 31p/kWh peak.

Rosie's meter switches 7 minutes late. So a one-hour afternoon boost (the worst case) will have 7 mins at 31p and 53 mins at 9p.

That's an average of (31 x 7/60) + (9 x 53/60) which is 11.6p/kWh. So it's still cheaper than EDF's E7 off-peak, and cheaper than Rosie's current E10 off-peak.

For the overnight 6 hours, so long as the heaters charge for more than an hour then the average tariff will be less than that, closer to 9p.

vienna28

Swipe said:

@vienna28 Does your IHD show the off peak tariff rate cost when it is active?

Swipe, no the IHD is not super accurate in displaying when off peak begins and ends.

With the Snug tariff they take half hourly readings from the smart meter.  Here is a breakdown from my bill of my 21 April usage.  At 6:30am on this day I forgot to turn my hot water off, so I overran into peak by 7 minutes.

Swipe

Thanks for that, Vienna28. TBH, I tend to shift my day back by 1 hour during winter, even more so during cold snaps, so I'm normally up well before 6:30am so can turn the heaters off at the wall manually if they are still charging after the window has ended. 

vienna28

Yes Swipe, the overrun into peak is not really a big deal.  It's not too difficult to avoid. 

Scot_39

debitcardmayhem said:

Rosie1001 said:

I don’t understand thou , if the meter is controlling the heaters etc how they run over 

The meter doesn’t know when the rates change , only when it switches on for  7 hours and then switches off, e.g. your meter switches on the circuit at  0007 it switches off at 0707, but the supplier charges from 0000-0700 ergo you lose 7 mins at the start and then have 7 mins at peak

From the SNUG FAQ

"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."

Octopus do not control the specification of the meters - nor do the fully explain - exactly how their Snug operation operates realtive to conventional meter parameters for E7/E10 etc - on ALCS settings in particular - as they do say they use half hourly billing and not E7/E10 twin register based billing.

So on conventional E7/E10 etc - the heating remains controlled by the meter - the ALCS calander, the tariff timing by the tariff timing paramters - both currently share the same offset - in Rosie1001 case 9m - on E10.

But with Snug - the billing works on half hourly consumption registers - that remain on the hour and half hour.

That is unlikely to be corrected given the march to Half Hourly Settlement for all electric consumption (initially at Supplier to Generator level).  (Ofgem have actually changed 1/2 hrly data protection built into original DAPF to enable by default the gathering of that 1/2 hrly data on all new meters / switches) 

There are timing examples to show that those who set say sub 6 hours do not get one simple block period - but a series of maybe 1/2 hr periods chosen no doubt based on market prices - maybe say half hourly - as these obervations were based on 1/2 hourly use charts not live restricted feed monitoring - so for 3 hours potentially 6 on / offs possible - for all such eventualities. 

Sample costs of delay

However given the price differentials cf even their E7 let alone many RTS / E10 - its potentially not that major a cost difference - unless you had a really long dealy (which they do warn - as above with "most respond within 15 minutes").

Say it was iirc your 9min - in an afternoon hour scenario - based on current ALCS behaviour

you still get 51 min at 9p    

and 9m in at peak 31p (from post on page 6 - which might by June or July rates ?)

So ave price  you would be paying would be  (51*9p+9*31p) / 60 = 12.3p for every kWh - assuming constant.

but in a longer charge period - so the guaranteed max

Youd be upto 5hr 51 min off peak + 9 min.  So as little as 9.55p.

(in just two of the simplest max charging cases)

And unless your heaters were set to the old max - which to be fair iirc Rosie1001's were when on RTS 5+2 - but many wont be for most of the winter for many others - they probably wouldnt still be charging after the full 6 hours - so during the 9 mins etc in many cases not charging - for many more likely far closer to if not the 9p.

Whereas on E10 - youd pay off peak for the full hour - so 14.8p  in that last post by Rosie1001 on SVT E10 - possibly -1.2p c 13.6p+/- (depending on how EDF apply the 1.2p - the Northern region multirate ave cap rate price drop today.)

Others like EOn charge far higher for their E10 off peak - now just over 18p for me.  So losing the 9 mins or even more less of an issue still vs 9p for most of the period.

And as EDF load their peak more to offset cheaper Off peak a higher 38p (-1.2p ?) outside E10s 10 hours for other uses vs Snugs 31p day rate.

Like anything its a whats best for you.  

Edit a few typos and user references to use Rose1001's 9m in examples

Scot_39

There is no overrun per se in the sense implied.

There is no mismatched billing - its twin register based and the ACLS swithching offset is common to tariff and ALCS calander iirc.

My ALCS switching delay - virtually 0 on my old smets1 - so close I don't even worry about it.  AS it was on old RTS and old digital in interim iirc.

The smart spec iirc allows for a range of 0-30min.  Never saw anyone here report theirs that high.

And iirc the label on my RTS said +/-15 min - not sure about the pre smart digital which was the first replacement for my RTS. Which EOn replaced after just a few years (without saying why - long before it's normal EOL cycle).

Swipe

Scot_39 said:

There is no overrun per se in the sense implied.

There is no mismatched billing - its twin register based and the ACLS swithching offset is common to tariff and ALCS calander iirc.

I still consider it an overrun as on E7 the tariff times are synced with the ACLS times so the offset becomes irrelevant from a billing point of view.

Scot_39

Its not an overrun though for conventional register based TOU tariffs - it's a deliberate design feature.

To stop 100,000s if not millions of homes in a region - switching large heating loads at the same time in a given grid supply / DNO regional timing block.

And so avoid the corresponsing voltage and frequency spikes that would accompany it if did.

Think of the sort of kettle surges after a major TV event - only thats typically 3kW - that we use the likes of Dinorwigs fast spin up generation for  - whereas even in my small all electric home - my ALCS switches 10kW+.

Gas heating is a lot more common now - it isn't in other parts fo the country.  There are 100,000s of homes in Scotland off grid - and with huge large power / energy demands - hence the relatively high all electric RTS metering repacement problems - many where mains gas isn't available still - or simply to expensive to add when is.

mmmmikey

It is clearly the intention to phase out legacy TOU / complex metering tariffs like E10 in favour of smart TOU tariffs. That has been fairly obvious for a few years and now stated explicitly by EDF (and possibly other suppliers?) The risk is that any continuation of E10 etc. could end up being just a short term stay-of-execution rather than a long term change. It is quite possible that E10 users will find themselves in exactly the same situation in another 3 months time. 

There is nothing to stop anyone who objects to this complaining. This doesn't have to be a done deal and could be changed. But it is equally possible that these tariffs will be stopped soon and it seems unlikely to me that electricity suppliers will be compelled to support legacy metering systems indefinitely.

If that does happen it would arguably be much better to get ahead of the game and switch to something different now in the summer months (i.e. outside the heating season) to allow plenty of time to get things sorted. Anyone hanging on to the very last minute to change runs the risk of that happening at the worst possible time, and needs to consider that risk carefully.

Something else to consider is that there are many more heating options available now than there were 30 or 40 years ago when many of these legacy heating systems were installed and the new systems are often less wasteful, easier to control and cheaper to run. There are also some straightforward options for just updating the controls to allow different smart tariffs to be used and options around phasing the replacement so the cost doesn't need to be borne in one go. There have been schemes in the past for those on low incomes to replace againg storage heaters at no cost to themselves, removing the need for E10, and I'm not sure if those schemes are still available.