Aclara smart meter + Scottish Power + Off peak electric water heater immersion

antokeffort

Surprise there isn’t more awareness about this whole farce ongoing considering most flats in this area have no gas what so ever and are all hooked up with electric water heaters. 

Electric water heater supplies hot taps shower bath etc. It’s recommended to time the water boil between suppliers off peak cheap rates, and off peak time chunk varies between suppliers. 

Scottish power off peak 12- 5am GMT

To my surprise despite the country moving to Britain summer time I predictably moved my water heater forwards 1 hour as expected. Only to now discover this was detrimental as Scottish powers off peak time chunk remains frozen on GMT Greenwich mean time all year round 365 days a year.  

Have now had to move the water heater back an hour to accommodate the billing system.

Wondering how many people are paying the more expensive full day rate during BST as they are moving heaters forwards not realising the smart meter and billing system remains locked on GMT. 1 hour a day of daytime peak rate is adding up I suppose.

Anyway most flats in city centre Liverpool are now electric only.

I am fairly switched on to this type of stuff. Opens my mind to how many people don’t realise they May be accidentally paying an hour of daytime peak rate.

If programmed correctly and used correctly on the right tariff i firmly believe the electric water heater can be the equivalent price or sometime less expensive than gas. 

4.5 kWh is what my water heater uses overnight for a full next day of hot water showers and washing. (No baths) had a lot of experimenting and reducing the boil time down in increments of 15 minutes per night until we would run out and discover the tolerance this way

radiators are disconnected from it totally separate electric units.

subjecttocontract

Even if your hot water tank is completely cold I very much doubt it would need the full 5 hours to achieve a temperature of 60 degrees. Immersion heaters generally are rated at 3kw.

Newbie_John

People don't realise as they find time of use tarriffs too complex.

There were days when I would adjust my immersion heater daily to match constantly changing Agile rates..

With your tarrif it's always 0-5am, one day a year you get 6h and one day you'll get 4h. Now depending on your set up - if smart meter turns on night circuit - then you dont have to do anything, but if your immersion heating device is quite old school - better set it to run from 1am.

Also at 6p/kWh I probably wouldn't bother trying to improve anything with it, it's already dirt cheap.

QrizB

Surprise there isn’t more awareness about this whole farce

Most all-electric properties with storage heaters and HW tanks would be on an Economy 7 tariff where the off-peak circuits are switched directly by the meter via ALCS. With this system you don't need to know the off-peak timings; it's all taken care of automatically.

You seem to be on an EV tariff that doesn't include ALCS switching, and in a property that wasn't wired for E7. Hence your dependence on manual timers.

Only to now discover this was detrimental as Scottish powers off peak time chunk remains frozen on GMT Greenwich mean time all year round 365 days a year.

That's normal for E7 (it dates from a time when the E7 timings were done by dumb equipment that didn't adjust for BST) but is unusual for an EV tariff.

If programmed correctly and used correctly on the right tariff i firmly believe the electric water heater can be the equivalent price or sometime less expensive than gas.

Everyone on Octopus Agile who is being paid to heat their water today will enthusiastically agree with you.

My off-peak electricity is also cheaper than my gas tariff at present.

The flip side is that your day rate (and mine) is somewhat more expensive than the SVT and so you'll be paying more than most for other uses of electricity. This might not be so important during the summer months but (per your previous thread) when you come to turn your electric panel heaters back on you might want to consider that.

4.5 kWh is what my water heater uses overnight for a full next day of hot water showers and washing.

Which suggests to me that you only need to run the immersion for the last hour and a half of your cheap-rate window, 0330-0500. Although leaving it on for the whole period might only cost a couple of pennies extra, depending on how well insulated it is.

Edit to add:

Here's the OP's previous thread, which has questions open for the OP to answer. (Ignore the reference to a storage heater, it's his HW tank.)

Swipe

Luckily my old Horstman Electronic 7 immersion heater timer (on my peak rate circuit) is clever enough to auto adjust the tariff times by 1 hour for BST so it still comes on for the last 2 hours of cheap rate.

Heedtheadvice

UW keep their customers up to date fortunately by email ( to me at least)

"

As the clocks change to British Summer Time (BST) on Sunday, 29 March, it's important to know that your off-peak hours will stay on Greenwich Mean Time (GMT) all year round.

What does this mean for you? To make the most of your cheaper off-peak rate, remember to use your appliances during GMT hours when the reduced rate is active.  For example, if your off-peak period is set between 12.30am and 7.30am GMT, you'll need to use your energy between 1.30am and 8.30am BST to benefit from the cheaper rate.  Remember, the clocks return to GMT on 25 October. Adjust your behaviour then, too, to take advantage of the cheaper rate.

"

Do SP not promulgate the info?

Scot_39

https://forums.moneysavingexpert.com/discussion/6663619/aclara-smart-meter-scottish-power-off-peak-electric-water-heater-immersion

What SP tariff only gives you 5 hours off-peak - are you on some sort of new smart meter EV special - but in a flat without an EV charger attached ?

Multirate tariffs vary in how they handle GMT / DST - some older meter tariffs like E7, E10 effectively shift in clock time as meters stay rigidly on GMT - so a meter that is 12-7am in winter will be 1am to 8 am in summer DST clock time.

Others - often the more modern - that are half hourly billing based say - like latest smart tariffs - often do remain fixed time and so 12-5 would stay 12-5.

And most suppliers I've seen are pretty good at pointing out the mainly new ones that do stay clock time - and most poeple used to old non smart meter multirate know the old ones do not - and that even their smart meter replacements - generally do not.

My RTS, my digital and now my smart meter all keep off peak times as GMT - so I now have to wait until 1am for night off peak to begin. From memory of the specs smart meters don't have to though - there are configuration switches that can be used iirc for tariff and presumably meter controlled restricted feed ALCS.

In fact iirc some posts - tariffs that claimed to be fixed - like one 5 hour ovenight BG special - reportedly behaved differently on different legacy meter brands - to those installed and configured by BG themselves.

And the advice to anyone with multirate - where meters not in control (as you say many modern flats have no restricted circuits, only self timed heating - space and hot water) - is to know your times and program accordingly.

Bearing in mind that although 12-5 may be fixed on a smart half hourly billed timing - older meters with ALCS controlling the heating - the tariff times and the ALCS - have a unique configurable delay preset - so 12-7am GMT / 1-8am DST - could in fact shift by upto 29m59s - some will not shift at all - but for many they will have 5-10min offsets - so need to know their individual true switching times - so if 10 min, say 12:10 to 07:10 GMT etc.

antokeffort

https://forums.moneysavingexpert.com/discussion/comment/81960411#Comment_81960411

yes correct it’s the only one I could select

Scot_39

https://forums.moneysavingexpert.com/discussion/comment/81960414#Comment_81960414

Suppliers will often default to showing only single rate to non traditional PC2 / multirate / restricted meters - but your 5 hr night rate is probably around half the equivalent E7 night rate - albeit for 2 hrs less everynight.

If your only using 4.5kWh though - 5 hours is more than enough - as thats likely only 4.5kWh/3kW tpyicala immersion heater rating - 1.5 hours

And so yes - very likely you will be being billed using half hourly meter consumption data.

And the times will not shift - but you might have to be careful with apps like bright when checking there time reporting shift - some have a user selection - others might be smarter.

Older TOU tariffs like E7 (still in millions of homes) tend to still use registered billing - with a set of preset start and end times (1 or 2 for E7 - upto 3 for my E10 etc) and the old standard was for them to stay on GMT - if you like harking back to the days when off peak was controlled by often sealed external electromechanical clock timers.

And its not all plain sailing - my 8 yr old smart meter pairing - meter and IHD - actually gets confused a little when IHD accessing it's history data registers (the buffers used for last 8 days, 5 weeks, 13 months) when used between 00:00 and 1am in DST - so if I look now - the results will be wrongly day stamped - but if look again after 1am - they will look OK again.