Gas bill - how to convert units into kWH?

Question

we have used 244 units in 2 months which according to our gas bill converts into 2703 kWh (Kilowatt-hours) used, does anyone know how this conversion is calculated? I have searching on the net but to no avail. Thanks

Answer 1

Is it not on your bill?

My gas bills from Eon have the formula used to convert the volume of gas used into kWh printed on them. Unfortunately I don't have one at hand.

Answer 2

You have to find out how much energy is in a unit of gas.  There are roughly 870 kJ of energy provided by a mole of natural gas.  2703 kWh is:

2703 kWh = 2703 kJ-hr/s = 2703*3600 kJ-hr-s/s-hr = 9.7x10^6 kJ

That means you used:

9.7x10^6 kJ/870 kJ/m = 1.11x10^4 moles of natural gas.

that comes out to around 245 cubic meters of methane, which is suspiciously close to your 244 units on your bill.  So I suspect a "unit" is a cubic meter of natural gas and the  2703 kWh represents the total energy in that volume of natural gas if you burned it and extracted the heat.  

Answer 3

you can find the awnswer on the n power website,  

Answer 4

You have to look up the most recent gas declaration of calorific value regulations. This gives a figure in megajoules (around 39) per cubic metre of gas which when divided by 3.6 gives a figure which must be multiplied by the units of gas consumed to give kilowatt-hours.

From the numbers you state it appears that the this figure is 39.9.

Divide be 3.6 and this gives 11.08. Multiply this by the gas units consumed - in your case 244 units and this gives 2703 Kilowatt-hours