Extremely High Gas Bill! Can This Be Correct?!?!? Help!!!

freegenie

mute_posting wrote: »

Well they wouldn't need to bother with all the calculations taking in conversion factors and calorific values if they could just apply the "unit" rate to your meter reading.

the calorific value chages (as does hte conversion factors) which is why they can't just apply it to the meter reading - so to answer, a "unit" is a Kwh not a m3 or ft3..

MP

Think you're right.

However their tarrif sheet is misleading. It says "per unit" not "per unit of kilowatt hour" or the like... We calculated our estimated bill based on per cubic metre...

If you figure it out it seems to be that the gas board here is therefore charging over 35pence for a cubic metre! Mad. I feel nauseated.

Sgt_Oddball

The reason why you aren't billed directly for the volumed used (from the meter) is that the amount of energy in the gas varies slightly over time. This is why, as mute posting says, they use the various conversion factors (which combined can vary between 11, 11.1, 11,2 etc. etc.) so that you pay for the energy you actually use rather than the volume.

This is why, although I think it is 7.9p per kwh unit, they could actually be generalising to per m3. As I said it only slightly changes around the x 11 mark. You should phone and double check.

mech_2

The low calorific value of the gas seems to be causing some confusion. It seems wrong compared to UK mains gas because it's LPG mixed with air. About half the volume is air, not fuel, therefore the calorific value is roughly halved.

I have done some searching and I have found this:
http://www.gov.im/lib/docs/oft/comparativeheatingschedulefebru4.pdf

Comparing this with the link freegenie already posted, it appears correct that the 7.9p is indeed per kWh. VAT is levied at 5% (the same as in the UK for domestic fuel) bringing the VAT inclusive price to 8.44p.

I don't know where they get the "average efficiency" of 90% from though. That is a little bewildering.

EPultra

Calculating your units (as recorded by the meter) into kilowatt hours (as billed for) is as follows:

Metric meter:
Units recorded X volume correction factor (always 1.022640) X calorific value (usually between 37.1 and 42.5) divided by 3.6 = kWh

Imperial meter
Units recorded X 2.83 X volume correction factor (always 1.022640) X calorific value (usually between 37.1 and 42.5) divided by 3.6 = kWh

Cardew

One cubic metre is 1 unit on a metric meter and equates to approx 11kWh.

So if your assumption that you have now used 1024 units is correct then that equates to a consumption of approx 11,300kWh.

The price of 7.995p cannot be correct for gas, if you are paying a daily standing charge - it should be 3p maximum.

Sounds like that is a price for electricity unit- or the primary gas units if you didn't have a daily standing charge.

mute_posting

Cardew wrote: »

One cubic metre is 1 unit on a metric meter and equates to approx 11kWh.

So if your assumption that you have now used 1024 units is correct then that equates to a consumption of approx 11,300kWh.

The price of 7.995p cannot be correct for gas, if you are paying a daily standing charge - it should be 3p maximum.

Sounds like that is a price for electricity unit- or the primary gas units if you didn't have a daily standing charge.

Think the prices OP gave are correct - they have posted the manx gas tarrif sheet above.

From what I can gather manx gas is actually LPG mixed with air

I know LPG is expensive but I'm not sure if it work out that expensive (especially when mixed with air)

mixing with air probably explains why 1 m3 is not 11 300 Kwh on IoM?

espresso

freegenie wrote:

My meter does say M3...

The bill has some thing on it saying "Gas consumed is converted into Kilowatt House as follows: Imperial to metric factor 1.0000000 times volume conversion 1.000000 times calorific value 18.6302 divided by kilowatt conversion factor (3.6) equals units in kilowatt hours used"

So its 01024 X 18.6302 / 3.6

Which equals 5299.1

SHOULD they be doing these conversions like this if already in M3??

Multiplying by 1.0 has no effect. Yours is a metric meter, if it was an imperial meter they would multiply by 2.83.

And it's an actual not estimate. I gave them readings on 21st April. The new meter was fitted on the 31st Jan (hence the reading of 00000)...

Thanks. Sorry this confuses me so much!

As far as I can see, the figures are correct! As this is LPG the calorific conversion factor is 18.6302.

In your case 1 cubic metre of gas equates to approx 5.18 kWh.

freegenie wrote:

Yup. That's what they've done!

They've charged us 7.9225 pence per KILOWATT hour...

This is correct and is the only way that any gas is charged so that the calorific conversion factor is calculated.

freegenie wrote:

It says we've used 5299.1 units in just 75 days! That is, on average, 70 units PER DAY!

That is a normal figure! I don't know where you have got the 14 units per day from!

I've read elsewhere average usage is all of about 14 units per day (national average) so I am sooooo confused! Units are 7.9225p per unit...

The units that you are charged for are definitely kWh.

At least your LPG is not going up again by 14% on the 1 May, see here.

...........

SwanJon

I agree with the above, the price is most likely per kWh. Every other supplier charges per kWh, and as well as taking into account calorific value, they also have to take into account imperial and metric meters.

How energy efficient is the cottage? Is it double galzed, are the walls/loft insulated etc?

Cardew

Didn't spot the IOM bit.

5,300kWh for 75 days in winter is not excessive consumption.

If that was on the mainland and cost, say, £120 - £150 for 2.5 months most people would be reasonably happy for that period in winter.

IMO the problem is not the high consumption but the high price!