NPower using seasonal ity table to calculate gas consumption.

matto

I suspect the difference lies in how they calculate the average calorific value versus the calorific value they use on a different basis to calculate bills.

At the end of the day we are talking about a 0.1% error which is pretty insignifcant. For instance, as far as I can work out the energy companies use 2.83 as the feet to metric conversion factor when the more accurate figure is 2.832 - which means if you are on an imperial meter you are being charge 0.1% less anyway.

Haza

Its funny how when there has been no price changes that the calculations are accurate but when there is a price increase you are undercharged at the cheaper rate then over charged the same amount at a higher rate. Seems to be a pattern in the spreadsheet.

I think I'll start looking for new supplier.

energylinx_2

Hope that these tools may help:
http://energylinx.co.uk/how_much_gas_used_in_a_year.html
This will allow you to enter your gas consumption, either in pounds or kWhs for any period and it will then, using industry standard seasonality factors mentioned it this thread, calculate your expected consumption or spend for a full calender year.

http://energylinx.co.uk/calorific.html
This link lets you see the calorific values which are used when calculating a gas bill for about the last ten years.

and as mentioned if you don't know the actual kWhs but have meter reading then you can use http://energylinx.co.uk/gas_meter_conversion.html to convert units into actual kWhs.

Hope that these help anyone looking to understand their gas bill.