A question for anyone who's been following Economy 7 rates for more than a few years

Gerry1

Cardew said:

A generally accepted 'rule of thumb' was that you needed to use 30% cheap rate electricity to justify an E7 tariff. However this break-even percentage has varied widely over the last 30+ years. It has been as low as 0%* and the last time I looked it was around 40%. For years it hovered around 10% to 15%.

I'm in a very similar position, but I don't recall the break even rate being as high as 40% for a very long time.  I switched to an E7 meter many years ago, despite having GCH; my night usage is about 22%.

Single rate has sometimes been cheaper in the last few years, sometimes E7 wins, so I just take whichever is the cheaper each time I switch.

coffeehound

Gerry1 said:

coffeehound said:

I suppose a major difference in the earlier days of E7 was that only the storage heaters and water heating went onto the cheap rate, and everything else stayed on peak rate all the time.  But then off-peak was much cheaper and we had fewer appliances on overnight.

There were tariffs like that and probably still are, but I'm fairly sure that E7 has always switched the whole supply over to the cheap rate. E7 was a refinement of the eight-hour White Meter tariff.

I might be wrong but was under the impression it was dictated by the hardware: the clock-controlled contactor just switched the off-peak circuits in and out via their dedicated off-peak meter.  

It might have been possible to switch everything over in that way, but there would have been a break in supply if so.  It was digital meters which made it possible to switch electronically between rates without interrupting supply.

Gerry1

coffeehound said:

Gerry1 said:

coffeehound said:

I suppose a major difference in the earlier days of E7 was that only the storage heaters and water heating went onto the cheap rate, and everything else stayed on peak rate all the time.  But then off-peak was much cheaper and we had fewer appliances on overnight.

There were tariffs like that and probably still are, but I'm fairly sure that E7 has always switched the whole supply over to the cheap rate. E7 was a refinement of the eight-hour White Meter tariff.

I might be wrong but was under the impression it was dictated by the hardware: the clock-controlled contactor just switched the off-peak circuits in and out via their dedicated off-peak meter.  

It might have been possible to switch everything over in that way, but there would have been a break in supply if so.  It was digital meters which made it possible to switch electronically between rates without interrupting supply.

No sir, IIRC I used to have a meter like this one, and I've never had a contactor.  My radio teleswitch just determines which register is incremented, there has never been any change in any electrical connection when the low rate kicks in.

coffeehound

Ah okay, I stand corrected.  Not had a meter like that.

MWT

coffeehound said:

I might be wrong but was under the impression it was dictated by the hardware: the clock-controlled contactor just switched the off-peak circuits in and out via their dedicated off-peak meter.  

It might have been possible to switch everything over in that way, but there would have been a break in supply if so.  It was digital meters which made it possible to switch electronically between rates without interrupting supply.

Gerry is right, my last meter was a clock controlled E7 meter and although they can control a contactor to switch a heavy load like night storage heaters, that doesn't stop them simply recording all the usage on a different register without physically switching the other loads.