Help - power consumption

[Andy Burns]

Shouldn't that be divide by 35.31?

[AnthonyL]

These are the figures copy and pasted from my Eon Electricity bill.

Consistently I find that I am disagreeing with you by a large factor which is why I'm trying to double check

Some sites seem to want the reading entered as 100's cu ft.

shows 0.2 cu ft to be 6kWh which agrees with my calcs and not the 0.6 you calculate.

If I'm misreading the meter by a factor of 10 or 100 I need to get back to my provider. But at the moment my spreadsheet calculates the billing amount as well and I seem to be in-line with Eon on this - though I would like for it to be overestimated by a factor of 100!

I think we agreed that my meter is measuring Cu ft though I'd like to understand what the dial on the right is doing. Seeing the photo shows one revolution = 0.071 cu ft - strange way of doing things as I expected (before I saw the photo) for it to be 0.1.

[Andy Burns]

does your meter read cu ft, or hundred cu ft?

i.e. 100/35.31 = 2.83

[Tim Streater]

There's a useful table here:

which says that natural gas has 0.0364 MJ/litre, at just over 1 bar. The table also says that 1MJ = 0.28kWh, so a litre of gas is 0.0102 kWh.

Now, 1 cu ft is 28317 cc, so 0.2 cu ft is 5.663 litres. So your .2 cu ft contains 5.663 x 0.0102 = 0.06 kWh.

Hmmm. That doesn't agree with either of you. However, 0.2 cu ft of gas containing 6kWh can't be right anyway, since a litre of home heating oil is 10 kWh, and that's a liquid, not a gas - much denser.

[Tim Streater]

I think you mean 0.2 *units*, not cu ft. If a unit is 100 cu ft then it would indeed be 6kWh, and I see now (looking further up that post) that Chris' calculated it at 0.06 kWh for 0.2 Cu ft, not 0.6.

[AnthonyL]

Then it seems to me that my electricity supplier is charging me as per units yet my meter is display cu ft - so they are charging me 100 times too much!

[AnthonyL]

I'm only going off what is written on the front and as per

I can't believe it is so bloody obtuse. I'm using Eon's formula to convert to kWh but I hadn't clocked and haven't yet seen anywhere that say 1 unit = 100 cu ft.

Where is it written on

?

[Chris Hogg]

I agree there seems to be something strange going on. All I can say is that 0.2 cu ft is a cube 7 inches on side, or a balloon 8.5 inches in diameter. I don't believe that such a volume holds 6 kWh of energy. If you slowly deflated the balloon over a period of an hour and burnt the gas, would you really get 6kW of heat out of it? That's equivalent two

3-kW electric fires or kettles running for an hour. Seems way too much to me. If I/you were underestimating the meter reading, and it should be up by a factor of ten, i.e. 2 cu.ft of gas not 0.2, by your calculation giving 60 kWh of heat, that would be the equivalent of twenty 3-kW electric fires or kettles going for one hour. Phew!

I'm not surprised you're confused. I think I am now!

[Dave Plowman (News)]

Since you're talking about 6 months, you must have had a bill or two by now? It might not be easy to calculate your unit cost exactly from that, but not difficult to be better than 10 times out. ;-)

[michael adams]

One unit (Imperial in this case) is one cubic foot.

As unlike with electric meter "units" which are universal with gas there are both metric and imperial units.

The reading in the picture is 7847.9 cubic ft

Only the 7847 figure is relevant for billing

The small dial on the right appears out of sync with the .9 red figure but then it does on mine as well.

Assuming for the sake of example that the reading before your last bill was 7747.9 cubic ft then on the next bill it will give your useage as 100 units.

With the subsequent calculations.

But regardless of this your gas consumption seems rather high. "Rather" being a bit of an understatement, IMO.

Your best bet is to log your usage for a couple of days with meter readings and maybe get it checked.

Failing that have you checked that there are no holes in the wall behind a cupboard maybe, with a hosepipe leading into next door's house ?

michael adams

...

[AnthonyL]

OK - the 4 black numbers on my meter are reading 100's of cu ft which the industry calls units.

So whilst I was reading that as being 7847.970 cu ft it is in fact

784790 cu ft*

• The dial is doing .071 cu ft for 1 revolution so I would need to sit and watch how many times it goes round - 14 to a cu ft.

It reminds me of old electricity meters where you could watch the red blob on the wheel go around and so work out how much the kettle had used. I think they need smart meters nowadays - clever progress isn't it?

[astrog29]

This is a vital fact which I thought others would have noticed. We had a timer control on our old boiler, and because there was no thermostat, it would still be firing up the heating when it was not needed, then we had to turn it off manually. But often as not, we would not notice and we would be heating an already heated house.

We got a new boiler with a thermostat, admittedly the old boiler was

15-20 years old and not very efficient, but our bills have dropped dramatically, and the house is now always comfortable.

Astrog

[Tim Streater]

If I hover the mouse over the picture of the imperial meter, the tip that shows up says "Imperial gas meter - showing gas units used in 100 cubic feet".

Also, look at the dial in the bottom right corner. Underneath it it says "1000 per rev". So the pointer moving from 0 to 1 is 100. And you have the evidence of the two dials above the bottom row, the right one counting in cu ft and the left one in "10 feet", as it is written.

[Tim Streater]

I think you'll find that it is 100 cu ft.

[Dave Plowman (News)]

Surely you'd notice if the house got too hot?

[Tim Streater]

No, you get 0.06 kWh out of it, as you already calculated. I came to the same answer independently.

[AnthonyL]

This is what is on my bill:

[quote] Period Meter no. Previous Present Units used kilowatt hours 19.11.15-1.2.16 0000406 7296 E 7596 C 300 hcf 9502

?300 units x2.83 (to get cubic metres) x1.02264 (conversion factor) x

39.4 (calorific value) ? 3.6 (to get kilowatt hours) = 9502 kWh?

We measure the gas you use in cubic feet, but like all suppliers we charge for gas in kilowatt hours. You can find the calculation we use to do this below your readings - all gas suppliers use the same calculation. To find out more, go to eonenergy.com/gascalculation [/endquote]

So each increment of the black number is 1 hcf and not 1 cu ft according to the ambiguous wording above and is at odds with what you are saying. If you are right I've used 3 hcf, I'm not using a lot of gas and Eon are overcharging me.

[michael adams]

My mistake. Obviously the cubic ft on the dial refers to the red figure and red dial

The units are the white on black ones. And to get those you simply deduct the units shown on the last bill.

michael adams

[AnthonyL]

Yes - that meter seems very consistent within itself - 10 increments of 100 (1hcf) = 1000 cu ft.

It still would only take the wording "1 unit = 100 cu ft" in the text to remove all ambiguity.

[michael adams]

First up 300 units is an awful lot.

Sorry I've only just caught up with the start of this thread.

"Six months ago my wife and I moved from a coal heated house to a gas fired centrally heated bungalow. "

If you've only lived in the property for six months, who provided the estimate for the bill three months ago ? I assume the meter was read, and that reading confirmed by yourself* when you bought the house ?

Because otherwise there might be a suspicion that the previous owner somehow got behind with their readings/estimates/payments despite the two year statutory requirement for readings.

michael adams

• In my area readings are subcontracted to G4S. Not only don't I trust them to always read the meter correctly i.e they don't - basically I usually do my own readings and didn't confirm the figure for the two year visit - meaning they had to come back and have another try as it was obviously wrong

- but I wouldn't trust them to make statutory readings either as required by their contract.