Energy a/cs clear as mud!

starsign47

I thought David Cameron said that Energy companies had to provide clear information on their bills? I moved house 12 weeks ago and BG are the energy supplier. They sent me an enormous bill after only two weeks which I disputed. This was followed up by several reminders and then another bill, and so it continued. I decided to switch supplier, gave BG and my new supplier the final readings and I got a closing bill. The outstanding amount did not tally with my calculations and so I queried this with them. The response was:
gas units used multiplied by the imperial to metric conversion factor of 2.83 to one decimal place multiplied by the volume conversion factor of 1.0226400 multiplied by the calorific value of 39.2000 divided by the kilowatt conversion factor of 3.6.
Please note, however, that the calorific value is variable - it is a measurement of the quality of gas supplied, and this can change from bill to bill.


I've worked in accounts all my working life, but I cannot get the hang of that!

Ectophile

The maths is a bit messy, and the number if significant digits varies wildly for no apparent reason. It's worse if you've got an old imperial meter.

An imperial meter measures in hundreds of cubic feet. 100 cu ft = 2.8316846592 cubic metres.

The gas is supplied to you slightly compressed, which means you get more gas in a cubic foot than you would if it was at air pressure. So they multiply by a volume conversion factor. Essentially, you're getting about 1.022 times as much gas as the meter suggests.

The calorific value converts cubic meters of gas to joules (the standard metric unit of heat). It will be a bit of an estimate based on typical natural gas. That way you're paying for the heat you're getting, which is what really matters.

The factor 3.6 (exactly - it's not an approximation) converts joules to kilowatt-hours. We've always paid for electricity in kWh, so it's nice to do the same for gas.

Cardew

The detail of the conversion from gas units(metric or Imperial) to kWh does appear complex; albeit it is only arithmetic.


However the customer doesn't really need that information as the bill shows the kWh.


If the customer wishes to calculate how many kWh they have used since the last bill they simply need to multiple a metric gas unit by 11.2 or an Imperial gas unit by 31.7 to give a close approximation.