How Much Cheaper Is Eco 7?

charlieheard

Cardew wrote:

As its Panto season can the audience join in?

...

At this point the Panto audience are cheering Paul and booing Charlieheard."Oh yes they are!"

Having re-read my T&C's and calculated my bill from scratch, you are of course right

My new tariff is split at the first 1000Kwh, and it is calcualted quarterly, so there I was assuming 1000/quarter. Having worked out the figures properly, I can now see that a tariff like that would be very unattractive!

But why the boos?

BTW, I'd checked all the available tariffs using Martin's recommended site, and was looking at a dual-fuel saving of £20-£30 p.a. which seemed tiny. I then looked individually, and managed to get £200 p.a. :j Well worth doing

Cardew

charlieheard wrote:

But why the boos?

It is a sign of endearment with a panto audience!

carpy

what are the latest thoughts on E7?

anyone know what Scottish Power's E7 rates are like because i've just changed to their capped price until 31/8/09 tariff from Eon?

just a thought do SP automatically put me on an E7 tariff because i selected it during price comparisons?

BexTech

russellgreeno wrote: »

A few years back, my partners parents (who we lived with) had Storage heaters installed and were switched to Eco 7.

The idea is great, let the heaters charge up when the electricity is cheap. The downside was, that, as OAPs they hardly ventured from the house all day, and therefore were burning lots of electricity during they day at THREE times the cost of the night-time electricity.

If you are out at work all day with no need for many appliances on while you are out, then it is great, but being marketed for OAP's isn't quite fair.

In our first flat we had E7 and storage heaters - gas was removed years previous due to being a tower block.

Storage Heaters were useless then and they were brand new ones and set up correctly.

Yes, they'd drink electricity during the night and you could feel the rooms warming up then, but whilst you are at work they are releasing the heat, so by the time you come home most the heat has gone and you start to feel cold, and the cycle continued.

dillyj

Last nght I switched on my night storage heaters on economy 7 and early this morning they were cold so had not been charging overnight - they were on all morning till at least 1.30 pm.

Do you pay according to the timer (so I am getting my other electricity at a cheaper rate) or am I being charged more because the E 7 timer is wrong?

tomstickland

I've just done a quick analysis.

First of all compare the E7 prices with the std single tariff prices.

I used BG Click 5.
Daytime electricity is 40% more expensive with E7.
Night time electricity is 40% cheaper, this has to be compared to the tier 2 daily rate. i.e. Assume that enough units are used per day to breach the tier 1 prices.

Express these as ratios.
I'll call the daytime price ratio "d". In this case it's 1.4 because it costs 1.4 times as much for dayime electricity.
I'll call the night time price ratio "n". In this case it's 0.6 because I pay 0.6 of the daytime rate (1-0.6 gives 0.4, ie: 40% cheaper).

Now, the effective unit cost now depends on how much night time electricity is used. I'll call the proportion "r". So if I use entirely day time electricity then r will be zero and the relative cost will be the same as ratio "d".
If I use entirely night time electricity then r= 1 and the relative cost will be the night time ratio.

So the effective cost can range from 1.4 to 0.6 for this example.

ie:
cost_ratio = (1-r)*d + r*n

For the break even point, the effective cost ratio is set to unity. The solution for r is then:
r = (d-1) / (d-n)

For d=1.4 and n=0.6 then r=0.5.
So I'd need to use 50% of the electricity overnight.

In fact I use 74% of my electricity overnight, so cost_ratio=0.84.
Hence I'm paying 0.84 of what I would be paying using single rate electricity.
So E7 saves me 16% in this example.

tomstickland

Repeating the exercise for Scottish Power energy saver 4 gives a much lower value for break even, at 20%.

With Discount Oct 2009 the numbers are slightly different, but still around 20%.

With Price Fix Dec 2009 the initial daytime rate is a bit higher, so the answer is 27%.

tomstickland

poundhappy wrote: »

I was under the impression that economy 7 only affected certain plug sockets / switches. I have economy 7 storage heating, and when I bought my flat was told that the only economy 7 supply switches were the 2 storage heaters and the hot water supply, so although the switches are always on the on position, they are only fed juice from the electric company between the night time hours. If I need extra hot water in the day, I need to turn on the other switch for 24hr electricity supply.

As far as I'm aware, I don't get cheap rates for any other appliances or convector heaters during the night.

All electricity used in the E7 period is chaarged at E7 rates.
To make this easier to implement then overnight only items are all connected to a secondary supply so that the meter can turn them all on a the optimum time.

dillyj

tomstickland wrote: »

All electricity used in the E7 period is chaarged at E7 rates.
To make this easier to implement then overnight only items are all connected to a secondary supply so that the meter can turn them all on a the optimum time.

Is the E 7 period decided by the company or dependent on when the E 7 timer in the meter switches it on?

Mine has come on all morning until lunchtime.

WOuld be grateful if anyone can answer this as I don't know if I am paying too much!

charlieheard

dillyj wrote: »

Is the E 7 period decided by the company or dependent on when the E 7 timer in the meter switches it on?

Mine has come on all morning until lunchtime.

WOuld be grateful if anyone can answer this as I don't know if I am paying too much!

All E7 setups that I have seen (not very many) have 2 meters, and the timer switches between the two. So you are charged one rate for everything connected to "overnight" usage, and the higher rate for everything connected to the other meter. In that kind of setup, you are charged on the meter readings for both meters at the appropriate rates.

Is that what you have?