Economy 7

[WayneLa]

Hello

I would like a bit of advice on Economy 7. Could someone help answer a few of these questions, please?

1. If you get Economy 7, when it switches over at night do all the rings switch over or is it only the timers outputs? i.e. does the primary ring main supply Economy 7.
2. I'm looking to have two larger S.Heater fitted in easy-wirable areas, these would be connected to the switched & 24hrs ring. However, access to other parts of the house would be difficult, so wanted to use a smaller <1.5KW heater on the main ring connected to timers - is this possible?

Thanks and appreciate the time.

Wayne

 

[Harry Bloomfield]

All of the power you use from the on time of E7 to the off time, is charged at the reduced tariff. All of the power you use from the off time of E7 through to the on time, is charged at the higher tariff.

That includes lights, TV, washing machine, water heater and the heaters.

 

[oldbutnotdead]

I believe that most Economy x installs nowadays don't have a separate night output, the whole house is cheap or dear depending on the time of day. Talk to your supplier, see what they are offering
And then do some sums. You may find the saving of firing the storage heaters on a cheaper tarriff doesn't balance out the cost of daytime power being significantly higher than on a standard setup

 

[WayneLa]

OK thanks. So that also answers my other questions. Much appreciated Harry.

 

[BlueLoo]

Do a power usage estimate of your daily usage vs nightime usage before you switch over. Do the estimate on am annual basis so as to incorporate the lack of heating load in the summer months.

To counter the cost of higher kwh during the day and a higher annual service charge, i think you need to be using over 50% of the total annual usage on the nightime rate to make it worthwhile.

 

[SUNRAY]

There are basically 3 systems
1. 2 meters where one is exclusive to ok peak rate, in which case only circuits connected to it are off peak. I have not been aware of this format being installed for a long time but I'm assured it may be.
2. A dual rate meter (2 meters in one) in which it records day and night usage on different dials, everything overnight is on the cheaper rate.
3. Smart meter... basically works the same as 2.

As long as it's not 1. your proposal is good as long as your existing circuits are suitable for the additional loads.

 

[BlueLoo]

Be careful going the smart meter route. The variable tarrifs are usually more expensive for people who have a dedicated reason for night time usage (charging cars,etc).

 

[SUNRAY]

There are basically 3 systems
1. 2 meters where one is exclusive to ok peak rate, in which case only circuits connected to it are off peak. I have not been aware of this format being installed for a long time but I'm assured it may be.
2. A dual rate meter (2 meters in one) in which it records day and night usage on different dials, everything overnight is on the cheaper rate.
3. Smart meter... basically works the same as 2.

As long as it's not 1. your proposal is good as long as your existing circuits are suitable for the additional loads.

several other replies while I penned mine. Indeed the cost of E7 is not as economical as it used to be as the cost of day rate has significantly increased recently.
If this is a rental property be very careful and make sure you have a chat with your EPC inspector before you make any changes.

 

[SUNRAY]

Be careful going the smart meter route. The variable tarrifs are usually more expensive for people who have a dedicated reason for night time usage (charging cars,etc).

This may be very true, I'm seeing differing reports about this at the moment which I suspect is different suppliers tariffs.

 

[BlueLoo]

This may be very true, I'm seeing differing reports about this at the moment which I suspect is different suppliers tariffs.

It's big news in Ireland where the networks are rolling them out under the premise of lower bills, rates, energy usage.
The reality is not quite that. Day rates are higher, especially during peak and whilst night rates are less than day rates, they are much higher than a night/day meter.

If you have high usage at night, in Ireland, you get a night meter, but you have to be proactive about stopping the networks from installing the smart meters. I have a big sign on my meter telling any installer to bog-off.

 

[JohnW2]

To counter the cost of higher kwh during the day and a higher annual service charge, i think you need to be using over 50% of the total annual usage on the nightime rate to make it worthwhile.

The (daily) 'Standing Charge' is usually not significantly different between dual-rate and single-rate tariffs - and, in any event, unless one's electricity usage in tiny, that Standing Charge is insignificant in relation to one's total electricity bill.

It varies between suppliers, but the 'break even' point for most is usually around 33%-35% of usage at night rate. Although I seem to be a definite exception (achieving 45% -50% at night rate despite not having storage heaters), I think that, for most people, a dual-rate tariff like E7 will only be cost-effective if one has storage heaters.

Kind Regards, John

 

[BlueLoo]

The (daily) 'Standing Charge' is usually not significantly different between dual-rate and single-rate tariffs - and, in any event, unless one's electricity usage in tiny, that Standing Charge is insignificant in relation to one's total electricity bill.

It varies between suppliers, but the 'break even' point for most is usually around 33%-35% of usage at night rate. Although I seem to be a definite exception (achieving 45% -50% at night rate despite not having storage heaters), I think that, for most people, a dual-rate tariff like E7 will only be cost-effective if one has storage heaters.

Kind Regards, John

Interesting.
In Ireland, the break point is >50%
In the UK, it seems better at >40% (money market).

Uk electricity seems more expensive than Ireland?

Must have a deeper look at that.

 

[SUNRAY]

M

The (daily) 'Standing Charge' is usually not significantly different between dual-rate and single-rate tariffs - and, in any event, unless one's electricity usage in tiny, that Standing Charge is insignificant in relation to one's total electricity bill.

It varies between suppliers, but the 'break even' point for most is usually around 33%-35% of usage at night rate. Although I seem to be a definite exception (achieving 45% -50% at night rate despite not having storage heaters), I think that, for most people, a dual-rate tariff like E7 will only be cost-effective if one has storage heaters.

Kind Regards, John

My father in law was in sheltered accomodation as was achieving 65-70% night rate at a price ratio better than 4:1 (Running only one of the 3 NSH's & immersion). The landlord changed over to wet gas heating with a heat meter in every flat. His heating and hot water cost soared.
Then came the row with the electricity supplier, he was on the twin meter system (with about 70m between meters & CU's) everymonth the night meter was clocking ~4 units despite the night CU being switched off. We could not convince them we wanted the meter removed.
I wanted to disable the contactor (3ph feeding 6 meters), which was very easy as all 5 contactors are fed by a Henly block from the mechanical time clock, but the wardermanager wouldn't let me.

 

[mattylad]

In my mother in laws E7 wired house, she has a separate fused unit that fuses all the E7 radials.
If you have this then 1 way of identifying them would be to turn them off and see what sockets etc. do not work.

 

[JohnW2]

Interesting. In Ireland, the break point is >50% In the UK, it seems better at >40% (money market). Uk electricity seems more expensive than Ireland?

There's obviously a fair bit of variation between suppliers but,in the UK (at least, England, which is what I know a bit about), the general situation is:

... something like 3-4 years ago, there was a dramatic change in lost E7 tariffs, such that the difference between day and night costs got a lot less. However, with most supplies, this was accompanied by the day ('peak') E7 cost getting much closer to the single-rate tariff figure, so that the break even' point (in terms of minimum night-time usage) fell appreciably.

[ with my penultimate 2-year tariff (2018-2020), whether intentionally of due to an error on their part (which Idid not complain about!), the daytime E7rate was identical to the single-tariff rate, so that the 'break even' point fell to 0% for that 2 years - i.e. I couldn't possibly lose! ]

Of course, if (as seems probable) night-time EV charging becomes increasingly prevalent, the night-time may not remain anything like as 'low a demand period' as it historically has been, so this may well be reflected in the tariffs before long!

Kind Regards, John